swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169)

* swarm: propagate ctx, enable opentracing

* swarm/tracing: log error when tracing is misconfigured

cmd/swarm/main.go

@@ -43,6 +43,7 @@ import (
 	"github.com/ethereum/go-ethereum/swarm"
 	bzzapi "github.com/ethereum/go-ethereum/swarm/api"
 	swarmmetrics "github.com/ethereum/go-ethereum/swarm/metrics"
+	"github.com/ethereum/go-ethereum/swarm/tracing"
 
 	"gopkg.in/urfave/cli.v1"
 )
@@ -430,12 +431,14 @@ pv(1) tool to get a progress bar:
 	app.Flags = append(app.Flags, rpcFlags...)
 	app.Flags = append(app.Flags, debug.Flags...)
 	app.Flags = append(app.Flags, swarmmetrics.Flags...)
+	app.Flags = append(app.Flags, tracing.Flags...)
 	app.Before = func(ctx *cli.Context) error {
 		runtime.GOMAXPROCS(runtime.NumCPU())
 		if err := debug.Setup(ctx, ""); err != nil {
 			return err
 		}
 		swarmmetrics.Setup(ctx)
+		tracing.Setup(ctx)
 		return nil
 	}
 	app.After = func(ctx *cli.Context) error {

cmd/swarm/swarm-smoke/upload_and_sync.go

@@ -77,8 +77,9 @@ func cliUploadAndSync(c *cli.Context) error {
 	log.Info("uploaded successfully", "hash", hash, "digest", fmt.Sprintf("%x", fhash))
 
 	if filesize < 10 {
-		time.Sleep(15 * time.Second)
+		time.Sleep(35 * time.Second)
 	} else {
+		time.Sleep(15 * time.Second)
 		time.Sleep(2 * time.Duration(filesize) * time.Second)
 	}
 
@@ -108,7 +109,7 @@ func cliUploadAndSync(c *cli.Context) error {
 // fetch is getting the requested `hash` from the `endpoint` and compares it with the `original` file
 func fetch(hash string, endpoint string, original []byte, ruid string) error {
 	log.Trace("sleeping", "ruid", ruid)
-	time.Sleep(1 * time.Second)
+	time.Sleep(5 * time.Second)
 
 	log.Trace("http get request", "ruid", ruid, "api", endpoint, "hash", hash)
 	res, err := http.Get(endpoint + "/bzz:/" + hash + "/")

p2p/protocols/protocol.go

@@ -29,6 +29,8 @@ devp2p subprotocols by abstracting away code standardly shared by protocols.
 package protocols
 
 import (
+	"bufio"
+	"bytes"
 	"context"
 	"fmt"
 	"io"
@@ -39,6 +41,10 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
+	"github.com/ethereum/go-ethereum/swarm/tracing"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 // error codes used by this  protocol scheme
@@ -109,6 +115,13 @@ func errorf(code int, format string, params ...interface{}) *Error {
 	}
 }
 
+// WrappedMsg is used to propagate marshalled context alongside message payloads
+type WrappedMsg struct {
+	Context []byte
+	Size    uint32
+	Payload []byte
+}
+
 // Spec is a protocol specification including its name and version as well as
 // the types of messages which are exchanged
 type Spec struct {
@@ -201,7 +214,7 @@ func NewPeer(p *p2p.Peer, rw p2p.MsgReadWriter, spec *Spec) *Peer {
 // the handler argument is a function which is called for each message received
 // from the remote peer, a returned error causes the loop to exit
 // resulting in disconnection
-func (p *Peer) Run(handler func(msg interface{}) error) error {
+func (p *Peer) Run(handler func(ctx context.Context, msg interface{}) error) error {
 	for {
 		if err := p.handleIncoming(handler); err != nil {
 			if err != io.EOF {
@@ -225,14 +238,47 @@ func (p *Peer) Drop(err error) {
 // message off to the peer
 // this low level call will be wrapped by libraries providing routed or broadcast sends
 // but often just used to forward and push messages to directly connected peers
-func (p *Peer) Send(msg interface{}) error {
+func (p *Peer) Send(ctx context.Context, msg interface{}) error {
 	defer metrics.GetOrRegisterResettingTimer("peer.send_t", nil).UpdateSince(time.Now())
 	metrics.GetOrRegisterCounter("peer.send", nil).Inc(1)
+
+	var b bytes.Buffer
+	if tracing.Enabled {
+		writer := bufio.NewWriter(&b)
+
+		tracer := opentracing.GlobalTracer()
+
+		sctx := spancontext.FromContext(ctx)
+
+		if sctx != nil {
+			err := tracer.Inject(
+				sctx,
+				opentracing.Binary,
+				writer)
+			if err != nil {
+				return err
+			}
+		}
+
+		writer.Flush()
+	}
+
+	r, err := rlp.EncodeToBytes(msg)
+	if err != nil {
+		return err
+	}
+
+	wmsg := WrappedMsg{
+		Context: b.Bytes(),
+		Size:    uint32(len(r)),
+		Payload: r,
+	}
+
 	code, found := p.spec.GetCode(msg)
 	if !found {
 		return errorf(ErrInvalidMsgType, "%v", code)
 	}
-	return p2p.Send(p.rw, code, msg)
+	return p2p.Send(p.rw, code, wmsg)
 }
 
 // handleIncoming(code)
@@ -243,7 +289,7 @@ func (p *Peer) Send(msg interface{}) error {
 // * checks for out-of-range message codes,
 // * handles decoding with reflection,
 // * call handlers as callbacks
-func (p *Peer) handleIncoming(handle func(msg interface{}) error) error {
+func (p *Peer) handleIncoming(handle func(ctx context.Context, msg interface{}) error) error {
 	msg, err := p.rw.ReadMsg()
 	if err != nil {
 		return err
@@ -255,11 +301,38 @@ func (p *Peer) handleIncoming(handle func(msg interface{}) error) error {
 		return errorf(ErrMsgTooLong, "%v > %v", msg.Size, p.spec.MaxMsgSize)
 	}
 
+	// unmarshal wrapped msg, which might contain context
+	var wmsg WrappedMsg
+	err = msg.Decode(&wmsg)
+	if err != nil {
+		log.Error(err.Error())
+		return err
+	}
+
+	ctx := context.Background()
+
+	// if tracing is enabled and the context coming within the request is
+	// not empty, try to unmarshal it
+	if tracing.Enabled && len(wmsg.Context) > 0 {
+		var sctx opentracing.SpanContext
+
+		tracer := opentracing.GlobalTracer()
+		sctx, err = tracer.Extract(
+			opentracing.Binary,
+			bytes.NewReader(wmsg.Context))
+		if err != nil {
+			log.Error(err.Error())
+			return err
+		}
+
+		ctx = spancontext.WithContext(ctx, sctx)
+	}
+
 	val, ok := p.spec.NewMsg(msg.Code)
 	if !ok {
 		return errorf(ErrInvalidMsgCode, "%v", msg.Code)
 	}
-	if err := msg.Decode(val); err != nil {
+	if err := rlp.DecodeBytes(wmsg.Payload, val); err != nil {
 		return errorf(ErrDecode, "<= %v: %v", msg, err)
 	}
 
@@ -268,7 +341,7 @@ func (p *Peer) handleIncoming(handle func(msg interface{}) error) error {
 	// which the handler is supposed to cast to the appropriate type
 	// it is entirely safe not to check the cast in the handler since the handler is
 	// chosen based on the proper type in the first place
-	if err := handle(val); err != nil {
+	if err := handle(ctx, val); err != nil {
 		return errorf(ErrHandler, "(msg code %v): %v", msg.Code, err)
 	}
 	return nil
@@ -288,14 +361,14 @@ func (p *Peer) Handshake(ctx context.Context, hs interface{}, verify func(interf
 		return nil, errorf(ErrHandshake, "unknown handshake message type: %T", hs)
 	}
 	errc := make(chan error, 2)
-	handle := func(msg interface{}) error {
+	handle := func(ctx context.Context, msg interface{}) error {
 		rhs = msg
 		if verify != nil {
 			return verify(rhs)
 		}
 		return nil
 	}
-	send := func() { errc <- p.Send(hs) }
+	send := func() { errc <- p.Send(ctx, hs) }
 	receive := func() { errc <- p.handleIncoming(handle) }
 
 	go func() {

p2p/protocols/protocol_test.go

@@ -104,7 +104,7 @@ func newProtocol(pp *p2ptest.TestPeerPool) func(*p2p.Peer, p2p.MsgReadWriter) er
 			return fmt.Errorf("handshake mismatch remote %v > local %v", rmhs.C, lhs.C)
 		}
 
-		handle := func(msg interface{}) error {
+		handle := func(ctx context.Context, msg interface{}) error {
 			switch msg := msg.(type) {
 
 			case *protoHandshake:
@@ -116,7 +116,7 @@ func newProtocol(pp *p2ptest.TestPeerPool) func(*p2p.Peer, p2p.MsgReadWriter) er
 					return fmt.Errorf("handshake mismatch remote %v > local %v", rhs.C, lhs.C)
 				}
 				lhs.C += rhs.C
-				return peer.Send(lhs)
+				return peer.Send(ctx, lhs)
 
 			case *kill:
 				// demonstrates use of peerPool, killing another peer connection as a response to a message

p2p/testing/protocoltester.go

@@ -180,7 +180,8 @@ func (m *mockNode) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
 	for {
 		select {
 		case trig := <-m.trigger:
-			m.err <- p2p.Send(rw, trig.Code, trig.Msg)
+			wmsg := Wrap(trig.Msg)
+			m.err <- p2p.Send(rw, trig.Code, wmsg)
 		case exps := <-m.expect:
 			m.err <- expectMsgs(rw, exps)
 		case <-m.stop:
@@ -220,7 +221,7 @@ func expectMsgs(rw p2p.MsgReadWriter, exps []Expect) error {
 		}
 		var found bool
 		for i, exp := range exps {
-			if exp.Code == msg.Code && bytes.Equal(actualContent, mustEncodeMsg(exp.Msg)) {
+			if exp.Code == msg.Code && bytes.Equal(actualContent, mustEncodeMsg(Wrap(exp.Msg))) {
 				if matched[i] {
 					return fmt.Errorf("message #%d received two times", i)
 				}
@@ -235,7 +236,7 @@ func expectMsgs(rw p2p.MsgReadWriter, exps []Expect) error {
 				if matched[i] {
 					continue
 				}
-				expected = append(expected, fmt.Sprintf("code %d payload %x", exp.Code, mustEncodeMsg(exp.Msg)))
+				expected = append(expected, fmt.Sprintf("code %d payload %x", exp.Code, mustEncodeMsg(Wrap(exp.Msg))))
 			}
 			return fmt.Errorf("unexpected message code %d payload %x, expected %s", msg.Code, actualContent, strings.Join(expected, " or "))
 		}
@@ -267,3 +268,17 @@ func mustEncodeMsg(msg interface{}) []byte {
 	}
 	return contentEnc
 }
+
+type WrappedMsg struct {
+	Context []byte
+	Size    uint32
+	Payload []byte
+}
+
+func Wrap(msg interface{}) interface{} {
+	data, _ := rlp.EncodeToBytes(msg)
+	return &WrappedMsg{
+		Size:    uint32(len(data)),
+		Payload: data,
+	}
+}

swarm/api/api.go

@@ -37,8 +37,10 @@ import (
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/swarm/log"
 	"github.com/ethereum/go-ethereum/swarm/multihash"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/storage"
 	"github.com/ethereum/go-ethereum/swarm/storage/mru"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 var (
@@ -263,6 +265,12 @@ func (a *API) Resolve(ctx context.Context, uri *URI) (storage.Address, error) {
 	apiResolveCount.Inc(1)
 	log.Trace("resolving", "uri", uri.Addr)
 
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"api.resolve")
+	defer sp.Finish()
+
 	// if the URI is immutable, check if the address looks like a hash
 	if uri.Immutable() {
 		key := uri.Address()
@@ -347,7 +355,7 @@ func (a *API) Get(ctx context.Context, manifestAddr storage.Address, path string
 			log.Trace("resource type", "key", manifestAddr, "hash", entry.Hash)
 			ctx, cancel := context.WithCancel(context.Background())
 			defer cancel()
-			rsrc, err := a.resource.Load(storage.Address(common.FromHex(entry.Hash)))
+			rsrc, err := a.resource.Load(ctx, storage.Address(common.FromHex(entry.Hash)))
 			if err != nil {
 				apiGetNotFound.Inc(1)
 				status = http.StatusNotFound
@@ -486,7 +494,7 @@ func (a *API) GetDirectoryTar(ctx context.Context, uri *URI) (io.ReadCloser, err
 
 			// retrieve the entry's key and size
 			reader, _ := a.Retrieve(ctx, storage.Address(common.Hex2Bytes(entry.Hash)))
-			size, err := reader.Size(nil)
+			size, err := reader.Size(ctx, nil)
 			if err != nil {
 				return err
 			}
@@ -883,7 +891,7 @@ func (a *API) BuildDirectoryTree(ctx context.Context, mhash string, nameresolver
 // ResourceLookup Looks up mutable resource updates at specific periods and versions
 func (a *API) ResourceLookup(ctx context.Context, addr storage.Address, period uint32, version uint32, maxLookup *mru.LookupParams) (string, []byte, error) {
 	var err error
-	rsrc, err := a.resource.Load(addr)
+	rsrc, err := a.resource.Load(ctx, addr)
 	if err != nil {
 		return "", nil, err
 	}

swarm/api/api_test.go

@@ -90,7 +90,7 @@ func testGet(t *testing.T, api *API, bzzhash, path string) *testResponse {
 		t.Fatalf("unexpected error: %v", err)
 	}
 	quitC := make(chan bool)
-	size, err := reader.Size(quitC)
+	size, err := reader.Size(context.TODO(), quitC)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

swarm/api/filesystem.go

@@ -277,7 +277,7 @@ func retrieveToFile(quitC chan bool, fileStore *storage.FileStore, addr storage.
 	}
 	reader, _ := fileStore.Retrieve(context.TODO(), addr)
 	writer := bufio.NewWriter(f)
-	size, err := reader.Size(quitC)
+	size, err := reader.Size(context.TODO(), quitC)
 	if err != nil {
 		return err
 	}

swarm/api/http/server.go

@@ -42,8 +42,11 @@ import (
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/swarm/api"
 	"github.com/ethereum/go-ethereum/swarm/log"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/storage"
 	"github.com/ethereum/go-ethereum/swarm/storage/mru"
+	opentracing "github.com/opentracing/opentracing-go"
+
 	"github.com/pborman/uuid"
 	"github.com/rs/cors"
 )
@@ -263,6 +266,13 @@ func (s *Server) HandlePostRaw(w http.ResponseWriter, r *Request) {
 
 	postRawCount.Inc(1)
 
+	ctx := r.Context()
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.post.raw")
+	defer sp.Finish()
+
 	toEncrypt := false
 	if r.uri.Addr == "encrypt" {
 		toEncrypt = true
@@ -286,7 +296,7 @@ func (s *Server) HandlePostRaw(w http.ResponseWriter, r *Request) {
 		return
 	}
 
-	addr, _, err := s.api.Store(r.Context(), r.Body, r.ContentLength, toEncrypt)
+	addr, _, err := s.api.Store(ctx, r.Body, r.ContentLength, toEncrypt)
 	if err != nil {
 		postRawFail.Inc(1)
 		Respond(w, r, err.Error(), http.StatusInternalServerError)
@@ -307,8 +317,15 @@ func (s *Server) HandlePostRaw(w http.ResponseWriter, r *Request) {
 // resulting manifest hash as a text/plain response
 func (s *Server) HandlePostFiles(w http.ResponseWriter, r *Request) {
 	log.Debug("handle.post.files", "ruid", r.ruid)
-
 	postFilesCount.Inc(1)
+
+	var sp opentracing.Span
+	ctx := r.Context()
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.post.files")
+	defer sp.Finish()
+
 	contentType, params, err := mime.ParseMediaType(r.Header.Get("Content-Type"))
 	if err != nil {
 		postFilesFail.Inc(1)
@@ -323,7 +340,7 @@ func (s *Server) HandlePostFiles(w http.ResponseWriter, r *Request) {
 
 	var addr storage.Address
 	if r.uri.Addr != "" && r.uri.Addr != "encrypt" {
-		addr, err = s.api.Resolve(r.Context(), r.uri)
+		addr, err = s.api.Resolve(ctx, r.uri)
 		if err != nil {
 			postFilesFail.Inc(1)
 			Respond(w, r, fmt.Sprintf("cannot resolve %s: %s", r.uri.Addr, err), http.StatusInternalServerError)
@@ -331,7 +348,7 @@ func (s *Server) HandlePostFiles(w http.ResponseWriter, r *Request) {
 		}
 		log.Debug("resolved key", "ruid", r.ruid, "key", addr)
 	} else {
-		addr, err = s.api.NewManifest(r.Context(), toEncrypt)
+		addr, err = s.api.NewManifest(ctx, toEncrypt)
 		if err != nil {
 			postFilesFail.Inc(1)
 			Respond(w, r, err.Error(), http.StatusInternalServerError)
@@ -340,7 +357,7 @@ func (s *Server) HandlePostFiles(w http.ResponseWriter, r *Request) {
 		log.Debug("new manifest", "ruid", r.ruid, "key", addr)
 	}
 
-	newAddr, err := s.api.UpdateManifest(r.Context(), addr, func(mw *api.ManifestWriter) error {
+	newAddr, err := s.api.UpdateManifest(ctx, addr, func(mw *api.ManifestWriter) error {
 		switch contentType {
 
 		case "application/x-tar":
@@ -509,6 +526,14 @@ func resourcePostMode(path string) (isRaw bool, frequency uint64, err error) {
 // and name "foo.eth" will be created
 func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 	log.Debug("handle.post.resource", "ruid", r.ruid)
+
+	var sp opentracing.Span
+	ctx := r.Context()
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.post.resource")
+	defer sp.Finish()
+
 	var err error
 	var addr storage.Address
 	var name string
@@ -525,7 +550,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 		name = r.uri.Addr
 
 		// the key is the content addressed root chunk holding mutable resource metadata information
-		addr, err = s.api.ResourceCreate(r.Context(), name, frequency)
+		addr, err = s.api.ResourceCreate(ctx, name, frequency)
 		if err != nil {
 			code, err2 := s.translateResourceError(w, r, "resource creation fail", err)
 
@@ -536,7 +561,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 		// we create a manifest so we can retrieve the resource with bzz:// later
 		// this manifest has a special "resource type" manifest, and its hash is the key of the mutable resource
 		// root chunk
-		m, err := s.api.NewResourceManifest(r.Context(), addr.Hex())
+		m, err := s.api.NewResourceManifest(ctx, addr.Hex())
 		if err != nil {
 			Respond(w, r, fmt.Sprintf("failed to create resource manifest: %v", err), http.StatusInternalServerError)
 			return
@@ -556,7 +581,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 		// that means that we retrieve the manifest and inspect its Hash member.
 		manifestAddr := r.uri.Address()
 		if manifestAddr == nil {
-			manifestAddr, err = s.api.Resolve(r.Context(), r.uri)
+			manifestAddr, err = s.api.Resolve(ctx, r.uri)
 			if err != nil {
 				getFail.Inc(1)
 				Respond(w, r, fmt.Sprintf("cannot resolve %s: %s", r.uri.Addr, err), http.StatusNotFound)
@@ -567,7 +592,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 		}
 
 		// get the root chunk key from the manifest
-		addr, err = s.api.ResolveResourceManifest(r.Context(), manifestAddr)
+		addr, err = s.api.ResolveResourceManifest(ctx, manifestAddr)
 		if err != nil {
 			getFail.Inc(1)
 			Respond(w, r, fmt.Sprintf("error resolving resource root chunk for %s: %s", r.uri.Addr, err), http.StatusNotFound)
@@ -576,7 +601,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 
 		log.Debug("handle.post.resource: resolved", "ruid", r.ruid, "manifestkey", manifestAddr, "rootchunkkey", addr)
 
-		name, _, err = s.api.ResourceLookup(r.Context(), addr, 0, 0, &mru.LookupParams{})
+		name, _, err = s.api.ResourceLookup(ctx, addr, 0, 0, &mru.LookupParams{})
 		if err != nil {
 			Respond(w, r, err.Error(), http.StatusNotFound)
 			return
@@ -592,7 +617,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 
 	// Multihash will be passed as hex-encoded data, so we need to parse this to bytes
 	if isRaw {
-		_, _, _, err = s.api.ResourceUpdate(r.Context(), name, data)
+		_, _, _, err = s.api.ResourceUpdate(ctx, name, data)
 		if err != nil {
 			Respond(w, r, err.Error(), http.StatusBadRequest)
 			return
@@ -603,7 +628,7 @@ func (s *Server) HandlePostResource(w http.ResponseWriter, r *Request) {
 			Respond(w, r, err.Error(), http.StatusBadRequest)
 			return
 		}
-		_, _, _, err = s.api.ResourceUpdateMultihash(r.Context(), name, bytesdata)
+		_, _, _, err = s.api.ResourceUpdateMultihash(ctx, name, bytesdata)
 		if err != nil {
 			Respond(w, r, err.Error(), http.StatusBadRequest)
 			return
@@ -730,10 +755,18 @@ func (s *Server) translateResourceError(w http.ResponseWriter, r *Request, supEr
 func (s *Server) HandleGet(w http.ResponseWriter, r *Request) {
 	log.Debug("handle.get", "ruid", r.ruid, "uri", r.uri)
 	getCount.Inc(1)
+
+	var sp opentracing.Span
+	ctx := r.Context()
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.get")
+	defer sp.Finish()
+
 	var err error
 	addr := r.uri.Address()
 	if addr == nil {
-		addr, err = s.api.Resolve(r.Context(), r.uri)
+		addr, err = s.api.Resolve(ctx, r.uri)
 		if err != nil {
 			getFail.Inc(1)
 			Respond(w, r, fmt.Sprintf("cannot resolve %s: %s", r.uri.Addr, err), http.StatusNotFound)
@@ -748,7 +781,7 @@ func (s *Server) HandleGet(w http.ResponseWriter, r *Request) {
 	// if path is set, interpret <key> as a manifest and return the
 	// raw entry at the given path
 	if r.uri.Path != "" {
-		walker, err := s.api.NewManifestWalker(r.Context(), addr, nil)
+		walker, err := s.api.NewManifestWalker(ctx, addr, nil)
 		if err != nil {
 			getFail.Inc(1)
 			Respond(w, r, fmt.Sprintf("%s is not a manifest", addr), http.StatusBadRequest)
@@ -796,8 +829,8 @@ func (s *Server) HandleGet(w http.ResponseWriter, r *Request) {
 	}
 
 	// check the root chunk exists by retrieving the file's size
-	reader, isEncrypted := s.api.Retrieve(r.Context(), addr)
+	reader, isEncrypted := s.api.Retrieve(ctx, addr)
-	if _, err := reader.Size(nil); err != nil {
+	if _, err := reader.Size(ctx, nil); err != nil {
 		getFail.Inc(1)
 		Respond(w, r, fmt.Sprintf("root chunk not found %s: %s", addr, err), http.StatusNotFound)
 		return
@@ -828,13 +861,21 @@ func (s *Server) HandleGet(w http.ResponseWriter, r *Request) {
 func (s *Server) HandleGetList(w http.ResponseWriter, r *Request) {
 	log.Debug("handle.get.list", "ruid", r.ruid, "uri", r.uri)
 	getListCount.Inc(1)
+
+	var sp opentracing.Span
+	ctx := r.Context()
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.get.list")
+	defer sp.Finish()
+
 	// ensure the root path has a trailing slash so that relative URLs work
 	if r.uri.Path == "" && !strings.HasSuffix(r.URL.Path, "/") {
 		http.Redirect(w, &r.Request, r.URL.Path+"/", http.StatusMovedPermanently)
 		return
 	}
 
-	addr, err := s.api.Resolve(r.Context(), r.uri)
+	addr, err := s.api.Resolve(ctx, r.uri)
 	if err != nil {
 		getListFail.Inc(1)
 		Respond(w, r, fmt.Sprintf("cannot resolve %s: %s", r.uri.Addr, err), http.StatusNotFound)
@@ -842,7 +883,7 @@ func (s *Server) HandleGetList(w http.ResponseWriter, r *Request) {
 	}
 	log.Debug("handle.get.list: resolved", "ruid", r.ruid, "key", addr)
 
-	list, err := s.api.GetManifestList(r.Context(), addr, r.uri.Path)
+	list, err := s.api.GetManifestList(ctx, addr, r.uri.Path)
 	if err != nil {
 		getListFail.Inc(1)
 		Respond(w, r, err.Error(), http.StatusInternalServerError)
@@ -877,19 +918,28 @@ func (s *Server) HandleGetList(w http.ResponseWriter, r *Request) {
 func (s *Server) HandleGetFile(w http.ResponseWriter, r *Request) {
 	log.Debug("handle.get.file", "ruid", r.ruid)
 	getFileCount.Inc(1)
+
+	var sp opentracing.Span
+	ctx := r.Context()
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"http.get.file")
+
 	// ensure the root path has a trailing slash so that relative URLs work
 	if r.uri.Path == "" && !strings.HasSuffix(r.URL.Path, "/") {
 		http.Redirect(w, &r.Request, r.URL.Path+"/", http.StatusMovedPermanently)
+		sp.Finish()
 		return
 	}
 	var err error
 	manifestAddr := r.uri.Address()
 
 	if manifestAddr == nil {
-		manifestAddr, err = s.api.Resolve(r.Context(), r.uri)
+		manifestAddr, err = s.api.Resolve(ctx, r.uri)
 		if err != nil {
 			getFileFail.Inc(1)
 			Respond(w, r, fmt.Sprintf("cannot resolve %s: %s", r.uri.Addr, err), http.StatusNotFound)
+			sp.Finish()
 			return
 		}
 	} else {
@@ -897,7 +947,8 @@ func (s *Server) HandleGetFile(w http.ResponseWriter, r *Request) {
 	}
 
 	log.Debug("handle.get.file: resolved", "ruid", r.ruid, "key", manifestAddr)
-	reader, contentType, status, contentKey, err := s.api.Get(r.Context(), manifestAddr, r.uri.Path)
+
+	reader, contentType, status, contentKey, err := s.api.Get(ctx, manifestAddr, r.uri.Path)
 
 	etag := common.Bytes2Hex(contentKey)
 	noneMatchEtag := r.Header.Get("If-None-Match")
@@ -905,6 +956,7 @@ func (s *Server) HandleGetFile(w http.ResponseWriter, r *Request) {
 	if noneMatchEtag != "" {
 		if bytes.Equal(storage.Address(common.Hex2Bytes(noneMatchEtag)), contentKey) {
 			Respond(w, r, "Not Modified", http.StatusNotModified)
+			sp.Finish()
 			return
 		}
 	}
@@ -918,34 +970,49 @@ func (s *Server) HandleGetFile(w http.ResponseWriter, r *Request) {
 			getFileFail.Inc(1)
 			Respond(w, r, err.Error(), http.StatusInternalServerError)
 		}
+		sp.Finish()
 		return
 	}
 
 	//the request results in ambiguous files
 	//e.g. /read with readme.md and readinglist.txt available in manifest
 	if status == http.StatusMultipleChoices {
-		list, err := s.api.GetManifestList(r.Context(), manifestAddr, r.uri.Path)
+		list, err := s.api.GetManifestList(ctx, manifestAddr, r.uri.Path)
 		if err != nil {
 			getFileFail.Inc(1)
 			Respond(w, r, err.Error(), http.StatusInternalServerError)
+			sp.Finish()
 			return
 		}
 
 		log.Debug(fmt.Sprintf("Multiple choices! --> %v", list), "ruid", r.ruid)
 		//show a nice page links to available entries
 		ShowMultipleChoices(w, r, list)
+		sp.Finish()
 		return
 	}
 
 	// check the root chunk exists by retrieving the file's size
-	if _, err := reader.Size(nil); err != nil {
+	if _, err := reader.Size(ctx, nil); err != nil {
 		getFileNotFound.Inc(1)
 		Respond(w, r, fmt.Sprintf("file not found %s: %s", r.uri, err), http.StatusNotFound)
+		sp.Finish()
 		return
 	}
 
+	buf, err := ioutil.ReadAll(newBufferedReadSeeker(reader, getFileBufferSize))
+	if err != nil {
+		getFileNotFound.Inc(1)
+		Respond(w, r, fmt.Sprintf("file not found %s: %s", r.uri, err), http.StatusNotFound)
+		sp.Finish()
+		return
+	}
+
+	log.Debug("got response in buffer", "len", len(buf), "ruid", r.ruid)
+	sp.Finish()
+
 	w.Header().Set("Content-Type", contentType)
-	http.ServeContent(w, &r.Request, "", time.Now(), newBufferedReadSeeker(reader, getFileBufferSize))
+	http.ServeContent(w, &r.Request, "", time.Now(), bytes.NewReader(buf))
 }
 
 // The size of buffer used for bufio.Reader on LazyChunkReader passed to

swarm/api/manifest.go

@@ -212,10 +212,10 @@ func loadManifest(ctx context.Context, fileStore *storage.FileStore, hash storag
 	return readManifest(manifestReader, hash, fileStore, isEncrypted, quitC)
 }
 
-func readManifest(manifestReader storage.LazySectionReader, hash storage.Address, fileStore *storage.FileStore, isEncrypted bool, quitC chan bool) (trie *manifestTrie, err error) { // non-recursive, subtrees are downloaded on-demand
+func readManifest(mr storage.LazySectionReader, hash storage.Address, fileStore *storage.FileStore, isEncrypted bool, quitC chan bool) (trie *manifestTrie, err error) { // non-recursive, subtrees are downloaded on-demand
 
 	// TODO check size for oversized manifests
-	size, err := manifestReader.Size(quitC)
+	size, err := mr.Size(mr.Context(), quitC)
 	if err != nil { // size == 0
 		// can't determine size means we don't have the root chunk
 		log.Trace("manifest not found", "key", hash)
@@ -228,7 +228,7 @@ func readManifest(manifestReader storage.LazySectionReader, hash storage.Address
 		return
 	}
 	manifestData := make([]byte, size)
-	read, err := manifestReader.Read(manifestData)
+	read, err := mr.Read(manifestData)
 	if int64(read) < size {
 		log.Trace("manifest not found", "key", hash)
 		if err == nil {

swarm/api/storage.go

@@ -72,7 +72,7 @@ func (s *Storage) Get(ctx context.Context, bzzpath string) (*Response, error) {
 		return nil, err
 	}
 	quitC := make(chan bool)
-	expsize, err := reader.Size(quitC)
+	expsize, err := reader.Size(ctx, quitC)
 	if err != nil {
 		return nil, err
 	}

swarm/fuse/fuse_file.go

@@ -86,7 +86,7 @@ func (sf *SwarmFile) Attr(ctx context.Context, a *fuse.Attr) error {
 	if sf.fileSize == -1 {
 		reader, _ := sf.mountInfo.swarmApi.Retrieve(ctx, sf.addr)
 		quitC := make(chan bool)
-		size, err := reader.Size(quitC)
+		size, err := reader.Size(ctx, quitC)
 		if err != nil {
 			log.Error("Couldnt get size of file %s : %v", sf.path, err)
 			return err

swarm/network/discovery.go

@@ -17,6 +17,7 @@
 package network
 
 import (
+	"context"
 	"fmt"
 	"sync"
 
@@ -48,7 +49,7 @@ func newDiscovery(p *BzzPeer, o Overlay) *discPeer {
 }
 
 // HandleMsg is the message handler that delegates incoming messages
-func (d *discPeer) HandleMsg(msg interface{}) error {
+func (d *discPeer) HandleMsg(ctx context.Context, msg interface{}) error {
 	switch msg := msg.(type) {
 
 	case *peersMsg:
@@ -99,14 +100,14 @@ func (d *discPeer) NotifyPeer(a OverlayAddr, po uint8) {
 	resp := &peersMsg{
 		Peers: []*BzzAddr{ToAddr(a)},
 	}
-	go d.Send(resp)
+	go d.Send(context.TODO(), resp)
 }
 
 // NotifyDepth sends a subPeers Msg to the receiver notifying them about
 // a change in the depth of saturation
 func (d *discPeer) NotifyDepth(po uint8) {
 	// log.Trace(fmt.Sprintf("%08x peer %08x notified of new depth %v", d.localAddr.Over()[:4], d.Address()[:4], po))
-	go d.Send(&subPeersMsg{Depth: po})
+	go d.Send(context.TODO(), &subPeersMsg{Depth: po})
 }
 
 /*
@@ -178,7 +179,7 @@ func (d *discPeer) handleSubPeersMsg(msg *subPeersMsg) error {
 		})
 		if len(peers) > 0 {
 			// log.Debug(fmt.Sprintf("%08x: %v peers sent to %v", d.overlay.BaseAddr(), len(peers), d))
-			go d.Send(&peersMsg{Peers: peers})
+			go d.Send(context.TODO(), &peersMsg{Peers: peers})
 		}
 	}
 	d.sentPeers = true

swarm/network/protocol.go

@@ -82,9 +82,9 @@ type Peer interface {
 type Conn interface {
 	ID() discover.NodeID                                                                  // the key that uniquely identifies the Node for the peerPool
 	Handshake(context.Context, interface{}, func(interface{}) error) (interface{}, error) // can send messages
-	Send(interface{}) error                                                               // can send messages
+	Send(context.Context, interface{}) error                                              // can send messages
 	Drop(error)                                                                           // disconnect this peer
-	Run(func(interface{}) error) error                                                    // the run function to run a protocol
+	Run(func(context.Context, interface{}) error) error                                   // the run function to run a protocol
 	Off() OverlayAddr
 }
 

swarm/network/stream/common_test.go

@@ -126,7 +126,7 @@ func NewStreamerService(ctx *adapters.ServiceContext) (node.Service, error) {
 	return testRegistry, nil
 }
 
-func defaultRetrieveFunc(id discover.NodeID) func(chunk *storage.Chunk) error {
+func defaultRetrieveFunc(id discover.NodeID) func(ctx context.Context, chunk *storage.Chunk) error {
 	return nil
 }
 
@@ -217,14 +217,14 @@ func newRoundRobinStore(stores ...storage.ChunkStore) *roundRobinStore {
 	}
 }
 
-func (rrs *roundRobinStore) Get(addr storage.Address) (*storage.Chunk, error) {
+func (rrs *roundRobinStore) Get(ctx context.Context, addr storage.Address) (*storage.Chunk, error) {
 	return nil, errors.New("get not well defined on round robin store")
 }
 
-func (rrs *roundRobinStore) Put(chunk *storage.Chunk) {
+func (rrs *roundRobinStore) Put(ctx context.Context, chunk *storage.Chunk) {
 	i := atomic.AddUint32(&rrs.index, 1)
 	idx := int(i) % len(rrs.stores)
-	rrs.stores[idx].Put(chunk)
+	rrs.stores[idx].Put(ctx, chunk)
 }
 
 func (rrs *roundRobinStore) Close() {
@@ -369,8 +369,8 @@ func newTestExternalClient(db *storage.DBAPI) *testExternalClient {
 	}
 }
 
-func (c *testExternalClient) NeedData(hash []byte) func() {
+func (c *testExternalClient) NeedData(ctx context.Context, hash []byte) func() {
-	chunk, _ := c.db.GetOrCreateRequest(hash)
+	chunk, _ := c.db.GetOrCreateRequest(ctx, hash)
 	if chunk.ReqC == nil {
 		return nil
 	}
@@ -429,7 +429,7 @@ func (s *testExternalServer) SetNextBatch(from uint64, to uint64) ([]byte, uint6
 	return b, from, to, nil, nil
 }
 
-func (s *testExternalServer) GetData([]byte) ([]byte, error) {
+func (s *testExternalServer) GetData(context.Context, []byte) ([]byte, error) {
 	return make([]byte, 4096), nil
 }
 

swarm/network/stream/delivery.go

@@ -17,6 +17,7 @@
 package stream
 
 import (
+	"context"
 	"errors"
 	"time"
 
@@ -25,7 +26,9 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/swarm/log"
 	"github.com/ethereum/go-ethereum/swarm/network"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/storage"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 const (
@@ -118,8 +121,8 @@ func (s *SwarmChunkServer) Close() {
 }
 
 // GetData retrives chunk data from db store
-func (s *SwarmChunkServer) GetData(key []byte) ([]byte, error) {
+func (s *SwarmChunkServer) GetData(ctx context.Context, key []byte) ([]byte, error) {
-	chunk, err := s.db.Get(storage.Address(key))
+	chunk, err := s.db.Get(ctx, storage.Address(key))
 	if err == storage.ErrFetching {
 		<-chunk.ReqC
 	} else if err != nil {
@@ -134,25 +137,37 @@ type RetrieveRequestMsg struct {
 	SkipCheck bool
 }
 
-func (d *Delivery) handleRetrieveRequestMsg(sp *Peer, req *RetrieveRequestMsg) error {
+func (d *Delivery) handleRetrieveRequestMsg(ctx context.Context, sp *Peer, req *RetrieveRequestMsg) error {
 	log.Trace("received request", "peer", sp.ID(), "hash", req.Addr)
 	handleRetrieveRequestMsgCount.Inc(1)
 
+	var osp opentracing.Span
+	ctx, osp = spancontext.StartSpan(
+		ctx,
+		"retrieve.request")
+	defer osp.Finish()
+
 	s, err := sp.getServer(NewStream(swarmChunkServerStreamName, "", false))
 	if err != nil {
 		return err
 	}
 	streamer := s.Server.(*SwarmChunkServer)
-	chunk, created := d.db.GetOrCreateRequest(req.Addr)
+	chunk, created := d.db.GetOrCreateRequest(ctx, req.Addr)
 	if chunk.ReqC != nil {
 		if created {
-			if err := d.RequestFromPeers(chunk.Addr[:], true, sp.ID()); err != nil {
+			if err := d.RequestFromPeers(ctx, chunk.Addr[:], true, sp.ID()); err != nil {
 				log.Warn("unable to forward chunk request", "peer", sp.ID(), "key", chunk.Addr, "err", err)
 				chunk.SetErrored(storage.ErrChunkForward)
 				return nil
 			}
 		}
 		go func() {
+			var osp opentracing.Span
+			ctx, osp = spancontext.StartSpan(
+				ctx,
+				"waiting.delivery")
+			defer osp.Finish()
+
 			t := time.NewTimer(10 * time.Minute)
 			defer t.Stop()
 
@@ -169,7 +184,7 @@ func (d *Delivery) handleRetrieveRequestMsg(sp *Peer, req *RetrieveRequestMsg) e
 			chunk.SetErrored(nil)
 
 			if req.SkipCheck {
-				err := sp.Deliver(chunk, s.priority)
+				err := sp.Deliver(ctx, chunk, s.priority)
 				if err != nil {
 					log.Warn("ERROR in handleRetrieveRequestMsg, DROPPING peer!", "err", err)
 					sp.Drop(err)
@@ -185,7 +200,7 @@ func (d *Delivery) handleRetrieveRequestMsg(sp *Peer, req *RetrieveRequestMsg) e
 		if length := len(chunk.SData); length < 9 {
 			log.Error("Chunk.SData to deliver is too short", "len(chunk.SData)", length, "address", chunk.Addr)
 		}
-		return sp.Deliver(chunk, s.priority)
+		return sp.Deliver(ctx, chunk, s.priority)
 	}
 	streamer.deliveryC <- chunk.Addr[:]
 	return nil
@@ -197,7 +212,13 @@ type ChunkDeliveryMsg struct {
 	peer  *Peer  // set in handleChunkDeliveryMsg
 }
 
-func (d *Delivery) handleChunkDeliveryMsg(sp *Peer, req *ChunkDeliveryMsg) error {
+func (d *Delivery) handleChunkDeliveryMsg(ctx context.Context, sp *Peer, req *ChunkDeliveryMsg) error {
+	var osp opentracing.Span
+	ctx, osp = spancontext.StartSpan(
+		ctx,
+		"chunk.delivery")
+	defer osp.Finish()
+
 	req.peer = sp
 	d.receiveC <- req
 	return nil
@@ -209,7 +230,7 @@ R:
 		processReceivedChunksCount.Inc(1)
 
 		// this should be has locally
-		chunk, err := d.db.Get(req.Addr)
+		chunk, err := d.db.Get(context.TODO(), req.Addr)
 		if err == nil {
 			continue R
 		}
@@ -224,7 +245,7 @@ R:
 		default:
 		}
 		chunk.SData = req.SData
-		d.db.Put(chunk)
+		d.db.Put(context.TODO(), chunk)
 
 		go func(req *ChunkDeliveryMsg) {
 			err := chunk.WaitToStore()
@@ -236,10 +257,11 @@ R:
 }
 
 // RequestFromPeers sends a chunk retrieve request to
-func (d *Delivery) RequestFromPeers(hash []byte, skipCheck bool, peersToSkip ...discover.NodeID) error {
+func (d *Delivery) RequestFromPeers(ctx context.Context, hash []byte, skipCheck bool, peersToSkip ...discover.NodeID) error {
 	var success bool
 	var err error
 	requestFromPeersCount.Inc(1)
+
 	d.overlay.EachConn(hash, 255, func(p network.OverlayConn, po int, nn bool) bool {
 		spId := p.(network.Peer).ID()
 		for _, p := range peersToSkip {
@@ -253,8 +275,7 @@ func (d *Delivery) RequestFromPeers(hash []byte, skipCheck bool, peersToSkip ...
 			log.Warn("Delivery.RequestFromPeers: peer not found", "id", spId)
 			return true
 		}
-		// TODO: skip light nodes that do not accept retrieve requests
+		err = sp.SendPriority(ctx, &RetrieveRequestMsg{
-		err = sp.SendPriority(&RetrieveRequestMsg{
 			Addr:      hash,
 			SkipCheck: skipCheck,
 		}, Top)

swarm/network/stream/delivery_test.go

@@ -46,7 +46,7 @@ func TestStreamerRetrieveRequest(t *testing.T) {
 
 	peerID := tester.IDs[0]
 
-	streamer.delivery.RequestFromPeers(hash0[:], true)
+	streamer.delivery.RequestFromPeers(context.TODO(), hash0[:], true)
 
 	err = tester.TestExchanges(p2ptest.Exchange{
 		Label: "RetrieveRequestMsg",
@@ -80,7 +80,7 @@ func TestStreamerUpstreamRetrieveRequestMsgExchangeWithoutStore(t *testing.T) {
 
 	peer := streamer.getPeer(peerID)
 
-	peer.handleSubscribeMsg(&SubscribeMsg{
+	peer.handleSubscribeMsg(context.TODO(), &SubscribeMsg{
 		Stream:   NewStream(swarmChunkServerStreamName, "", false),
 		History:  nil,
 		Priority: Top,
@@ -131,7 +131,7 @@ func TestStreamerUpstreamRetrieveRequestMsgExchange(t *testing.T) {
 
 	stream := NewStream(swarmChunkServerStreamName, "", false)
 
-	peer.handleSubscribeMsg(&SubscribeMsg{
+	peer.handleSubscribeMsg(context.TODO(), &SubscribeMsg{
 		Stream:   stream,
 		History:  nil,
 		Priority: Top,
@@ -140,7 +140,7 @@ func TestStreamerUpstreamRetrieveRequestMsgExchange(t *testing.T) {
 	hash := storage.Address(hash0[:])
 	chunk := storage.NewChunk(hash, nil)
 	chunk.SData = hash
-	localStore.Put(chunk)
+	localStore.Put(context.TODO(), chunk)
 	chunk.WaitToStore()
 
 	err = tester.TestExchanges(p2ptest.Exchange{
@@ -179,7 +179,7 @@ func TestStreamerUpstreamRetrieveRequestMsgExchange(t *testing.T) {
 	hash = storage.Address(hash1[:])
 	chunk = storage.NewChunk(hash, nil)
 	chunk.SData = hash1[:]
-	localStore.Put(chunk)
+	localStore.Put(context.TODO(), chunk)
 	chunk.WaitToStore()
 
 	err = tester.TestExchanges(p2ptest.Exchange{
@@ -234,7 +234,7 @@ func TestStreamerDownstreamChunkDeliveryMsgExchange(t *testing.T) {
 
 	chunkKey := hash0[:]
 	chunkData := hash1[:]
-	chunk, created := localStore.GetOrCreateRequest(chunkKey)
+	chunk, created := localStore.GetOrCreateRequest(context.TODO(), chunkKey)
 
 	if !created {
 		t.Fatal("chunk already exists")
@@ -285,7 +285,7 @@ func TestStreamerDownstreamChunkDeliveryMsgExchange(t *testing.T) {
 	case <-chunk.ReqC:
 	}
 
-	storedChunk, err := localStore.Get(chunkKey)
+	storedChunk, err := localStore.Get(context.TODO(), chunkKey)
 	if err != nil {
 		t.Fatalf("Expected no error, got %v", err)
 	}
@@ -401,8 +401,8 @@ func testDeliveryFromNodes(t *testing.T, nodes, conns, chunkCount int, skipCheck
 		}
 		// create a retriever FileStore for the pivot node
 		delivery := deliveries[sim.IDs[0]]
-		retrieveFunc := func(chunk *storage.Chunk) error {
+		retrieveFunc := func(ctx context.Context, chunk *storage.Chunk) error {
-			return delivery.RequestFromPeers(chunk.Addr[:], skipCheck)
+			return delivery.RequestFromPeers(ctx, chunk.Addr[:], skipCheck)
 		}
 		netStore := storage.NewNetStore(sim.Stores[0].(*storage.LocalStore), retrieveFunc)
 		fileStore := storage.NewFileStore(netStore, storage.NewFileStoreParams())
@@ -617,8 +617,8 @@ func benchmarkDeliveryFromNodes(b *testing.B, nodes, conns, chunkCount int, skip
 	// create a retriever FileStore for the pivot node
 	// by now deliveries are set for each node by the streamer service
 	delivery := deliveries[sim.IDs[0]]
-	retrieveFunc := func(chunk *storage.Chunk) error {
+	retrieveFunc := func(ctx context.Context, chunk *storage.Chunk) error {
-		return delivery.RequestFromPeers(chunk.Addr[:], skipCheck)
+		return delivery.RequestFromPeers(ctx, chunk.Addr[:], skipCheck)
 	}
 	netStore := storage.NewNetStore(sim.Stores[0].(*storage.LocalStore), retrieveFunc)
 
@@ -650,7 +650,7 @@ Loop:
 		errs := make(chan error)
 		for _, hash := range hashes {
 			go func(h storage.Address) {
-				_, err := netStore.Get(h)
+				_, err := netStore.Get(ctx, h)
 				log.Warn("test check netstore get", "hash", h, "err", err)
 				errs <- err
 			}(hash)

swarm/network/stream/messages.go

@@ -17,6 +17,7 @@
 package stream
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"sync"
@@ -25,7 +26,9 @@ import (
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/swarm/log"
 	bv "github.com/ethereum/go-ethereum/swarm/network/bitvector"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/storage"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 // Stream defines a unique stream identifier.
@@ -71,17 +74,17 @@ type RequestSubscriptionMsg struct {
 	Priority uint8  // delivered on priority channel
 }
 
-func (p *Peer) handleRequestSubscription(req *RequestSubscriptionMsg) (err error) {
+func (p *Peer) handleRequestSubscription(ctx context.Context, req *RequestSubscriptionMsg) (err error) {
 	log.Debug(fmt.Sprintf("handleRequestSubscription: streamer %s to subscribe to %s with stream %s", p.streamer.addr.ID(), p.ID(), req.Stream))
 	return p.streamer.Subscribe(p.ID(), req.Stream, req.History, req.Priority)
 }
 
-func (p *Peer) handleSubscribeMsg(req *SubscribeMsg) (err error) {
+func (p *Peer) handleSubscribeMsg(ctx context.Context, req *SubscribeMsg) (err error) {
 	metrics.GetOrRegisterCounter("peer.handlesubscribemsg", nil).Inc(1)
 
 	defer func() {
 		if err != nil {
-			if e := p.Send(SubscribeErrorMsg{
+			if e := p.Send(context.TODO(), SubscribeErrorMsg{
 				Error: err.Error(),
 			}); e != nil {
 				log.Error("send stream subscribe error message", "err", err)
@@ -181,9 +184,15 @@ func (m OfferedHashesMsg) String() string {
 
 // handleOfferedHashesMsg protocol msg handler calls the incoming streamer interface
 // Filter method
-func (p *Peer) handleOfferedHashesMsg(req *OfferedHashesMsg) error {
+func (p *Peer) handleOfferedHashesMsg(ctx context.Context, req *OfferedHashesMsg) error {
 	metrics.GetOrRegisterCounter("peer.handleofferedhashes", nil).Inc(1)
 
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"handle.offered.hashes")
+	defer sp.Finish()
+
 	c, _, err := p.getOrSetClient(req.Stream, req.From, req.To)
 	if err != nil {
 		return err
@@ -197,7 +206,7 @@ func (p *Peer) handleOfferedHashesMsg(req *OfferedHashesMsg) error {
 	for i := 0; i < len(hashes); i += HashSize {
 		hash := hashes[i : i+HashSize]
 
-		if wait := c.NeedData(hash); wait != nil {
+		if wait := c.NeedData(ctx, hash); wait != nil {
 			want.Set(i/HashSize, true)
 			wg.Add(1)
 			// create request and wait until the chunk data arrives and is stored
@@ -260,7 +269,7 @@ func (p *Peer) handleOfferedHashesMsg(req *OfferedHashesMsg) error {
 			return
 		}
 		log.Trace("sending want batch", "peer", p.ID(), "stream", msg.Stream, "from", msg.From, "to", msg.To)
-		err := p.SendPriority(msg, c.priority)
+		err := p.SendPriority(ctx, msg, c.priority)
 		if err != nil {
 			log.Warn("SendPriority err, so dropping peer", "err", err)
 			p.Drop(err)
@@ -285,7 +294,7 @@ func (m WantedHashesMsg) String() string {
 // handleWantedHashesMsg protocol msg handler
 // * sends the next batch of unsynced keys
 // * sends the actual data chunks as per WantedHashesMsg
-func (p *Peer) handleWantedHashesMsg(req *WantedHashesMsg) error {
+func (p *Peer) handleWantedHashesMsg(ctx context.Context, req *WantedHashesMsg) error {
 	metrics.GetOrRegisterCounter("peer.handlewantedhashesmsg", nil).Inc(1)
 
 	log.Trace("received wanted batch", "peer", p.ID(), "stream", req.Stream, "from", req.From, "to", req.To)
@@ -314,7 +323,7 @@ func (p *Peer) handleWantedHashesMsg(req *WantedHashesMsg) error {
 			metrics.GetOrRegisterCounter("peer.handlewantedhashesmsg.actualget", nil).Inc(1)
 
 			hash := hashes[i*HashSize : (i+1)*HashSize]
-			data, err := s.GetData(hash)
+			data, err := s.GetData(ctx, hash)
 			if err != nil {
 				return fmt.Errorf("handleWantedHashesMsg get data %x: %v", hash, err)
 			}
@@ -323,7 +332,7 @@ func (p *Peer) handleWantedHashesMsg(req *WantedHashesMsg) error {
 			if length := len(chunk.SData); length < 9 {
 				log.Error("Chunk.SData to sync is too short", "len(chunk.SData)", length, "address", chunk.Addr)
 			}
-			if err := p.Deliver(chunk, s.priority); err != nil {
+			if err := p.Deliver(ctx, chunk, s.priority); err != nil {
 				return err
 			}
 		}
@@ -363,7 +372,7 @@ func (m TakeoverProofMsg) String() string {
 	return fmt.Sprintf("Stream: '%v' [%v-%v], Root: %x, Sig: %x", m.Stream, m.Start, m.End, m.Root, m.Sig)
 }
 
-func (p *Peer) handleTakeoverProofMsg(req *TakeoverProofMsg) error {
+func (p *Peer) handleTakeoverProofMsg(ctx context.Context, req *TakeoverProofMsg) error {
 	_, err := p.getServer(req.Stream)
 	// store the strongest takeoverproof for the stream in streamer
 	return err

swarm/network/stream/peer.go

@@ -27,8 +27,10 @@ import (
 	"github.com/ethereum/go-ethereum/swarm/log"
 	pq "github.com/ethereum/go-ethereum/swarm/network/priorityqueue"
 	"github.com/ethereum/go-ethereum/swarm/network/stream/intervals"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/state"
 	"github.com/ethereum/go-ethereum/swarm/storage"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 var sendTimeout = 30 * time.Second
@@ -62,6 +64,11 @@ type Peer struct {
 	quit         chan struct{}
 }
 
+type WrappedPriorityMsg struct {
+	Context context.Context
+	Msg     interface{}
+}
+
 // NewPeer is the constructor for Peer
 func NewPeer(peer *protocols.Peer, streamer *Registry) *Peer {
 	p := &Peer{
@@ -74,7 +81,10 @@ func NewPeer(peer *protocols.Peer, streamer *Registry) *Peer {
 		quit:         make(chan struct{}),
 	}
 	ctx, cancel := context.WithCancel(context.Background())
-	go p.pq.Run(ctx, func(i interface{}) { p.Send(i) })
+	go p.pq.Run(ctx, func(i interface{}) {
+		wmsg := i.(WrappedPriorityMsg)
+		p.Send(wmsg.Context, wmsg.Msg)
+	})
 	go func() {
 		<-p.quit
 		cancel()
@@ -83,25 +93,41 @@ func NewPeer(peer *protocols.Peer, streamer *Registry) *Peer {
 }
 
 // Deliver sends a storeRequestMsg protocol message to the peer
-func (p *Peer) Deliver(chunk *storage.Chunk, priority uint8) error {
+func (p *Peer) Deliver(ctx context.Context, chunk *storage.Chunk, priority uint8) error {
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"send.chunk.delivery")
+	defer sp.Finish()
+
 	msg := &ChunkDeliveryMsg{
 		Addr:  chunk.Addr,
 		SData: chunk.SData,
 	}
-	return p.SendPriority(msg, priority)
+	return p.SendPriority(ctx, msg, priority)
 }
 
 // SendPriority sends message to the peer using the outgoing priority queue
-func (p *Peer) SendPriority(msg interface{}, priority uint8) error {
+func (p *Peer) SendPriority(ctx context.Context, msg interface{}, priority uint8) error {
 	defer metrics.GetOrRegisterResettingTimer(fmt.Sprintf("peer.sendpriority_t.%d", priority), nil).UpdateSince(time.Now())
 	metrics.GetOrRegisterCounter(fmt.Sprintf("peer.sendpriority.%d", priority), nil).Inc(1)
-	ctx, cancel := context.WithTimeout(context.Background(), sendTimeout)
+	cctx, cancel := context.WithTimeout(context.Background(), sendTimeout)
 	defer cancel()
-	return p.pq.Push(ctx, msg, int(priority))
+	wmsg := WrappedPriorityMsg{
+		Context: ctx,
+		Msg:     msg,
+	}
+	return p.pq.Push(cctx, wmsg, int(priority))
 }
 
 // SendOfferedHashes sends OfferedHashesMsg protocol msg
 func (p *Peer) SendOfferedHashes(s *server, f, t uint64) error {
+	var sp opentracing.Span
+	ctx, sp := spancontext.StartSpan(
+		context.TODO(),
+		"send.offered.hashes")
+	defer sp.Finish()
+
 	hashes, from, to, proof, err := s.SetNextBatch(f, t)
 	if err != nil {
 		return err
@@ -124,7 +150,7 @@ func (p *Peer) SendOfferedHashes(s *server, f, t uint64) error {
 		Stream:        s.stream,
 	}
 	log.Trace("Swarm syncer offer batch", "peer", p.ID(), "stream", s.stream, "len", len(hashes), "from", from, "to", to)
-	return p.SendPriority(msg, s.priority)
+	return p.SendPriority(ctx, msg, s.priority)
 }
 
 func (p *Peer) getServer(s Stream) (*server, error) {

swarm/network/stream/snapshot_retrieval_test.go

@@ -55,10 +55,10 @@ func initRetrievalTest() {
 	//deliveries for each node
 	deliveries = make(map[discover.NodeID]*Delivery)
 	//global retrieve func
-	getRetrieveFunc = func(id discover.NodeID) func(chunk *storage.Chunk) error {
+	getRetrieveFunc = func(id discover.NodeID) func(ctx context.Context, chunk *storage.Chunk) error {
-		return func(chunk *storage.Chunk) error {
+		return func(ctx context.Context, chunk *storage.Chunk) error {
 			skipCheck := true
-			return deliveries[id].RequestFromPeers(chunk.Addr[:], skipCheck)
+			return deliveries[id].RequestFromPeers(ctx, chunk.Addr[:], skipCheck)
 		}
 	}
 	//registries, map of discover.NodeID to its streamer
@@ -412,7 +412,7 @@ func runFileRetrievalTest(nodeCount int) error {
 		for i, hash := range conf.hashes {
 			reader, _ := fileStore.Retrieve(context.TODO(), hash)
 			//check that we can read the file size and that it corresponds to the generated file size
-			if s, err := reader.Size(nil); err != nil || s != int64(len(randomFiles[i])) {
+			if s, err := reader.Size(context.TODO(), nil); err != nil || s != int64(len(randomFiles[i])) {
 				allSuccess = false
 				log.Warn("Retrieve error", "err", err, "hash", hash, "nodeId", id)
 			} else {
@@ -699,7 +699,7 @@ func runRetrievalTest(chunkCount int, nodeCount int) error {
 		for _, chnk := range conf.hashes {
 			reader, _ := fileStore.Retrieve(context.TODO(), chnk)
 			//assuming that reading the Size of the chunk is enough to know we found it
-			if s, err := reader.Size(nil); err != nil || s != chunkSize {
+			if s, err := reader.Size(context.TODO(), nil); err != nil || s != chunkSize {
 				allSuccess = false
 				log.Warn("Retrieve error", "err", err, "chunk", chnk, "nodeId", id)
 			} else {

swarm/network/stream/snapshot_sync_test.go

@@ -437,7 +437,7 @@ func runSyncTest(chunkCount int, nodeCount int, live bool, history bool) error {
 			} else {
 				//use the actual localstore
 				lstore := stores[id]
-				_, err = lstore.Get(chunk)
+				_, err = lstore.Get(context.TODO(), chunk)
 			}
 			if err != nil {
 				log.Warn(fmt.Sprintf("Chunk %s NOT found for id %s", chunk, id))

swarm/network/stream/stream.go

@@ -32,8 +32,10 @@ import (
 	"github.com/ethereum/go-ethereum/swarm/network"
 	"github.com/ethereum/go-ethereum/swarm/network/stream/intervals"
 	"github.com/ethereum/go-ethereum/swarm/pot"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
 	"github.com/ethereum/go-ethereum/swarm/state"
 	"github.com/ethereum/go-ethereum/swarm/storage"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 const (
@@ -235,7 +237,7 @@ func (r *Registry) RequestSubscription(peerId discover.NodeID, s Stream, h *Rang
 		if e, ok := err.(*notFoundError); ok && e.t == "server" {
 			// request subscription only if the server for this stream is not created
 			log.Debug("RequestSubscription ", "peer", peerId, "stream", s, "history", h)
-			return peer.Send(&RequestSubscriptionMsg{
+			return peer.Send(context.TODO(), &RequestSubscriptionMsg{
 				Stream:   s,
 				History:  h,
 				Priority: prio,
@@ -285,7 +287,7 @@ func (r *Registry) Subscribe(peerId discover.NodeID, s Stream, h *Range, priorit
 	}
 	log.Debug("Subscribe ", "peer", peerId, "stream", s, "history", h)
 
-	return peer.SendPriority(msg, priority)
+	return peer.SendPriority(context.TODO(), msg, priority)
 }
 
 func (r *Registry) Unsubscribe(peerId discover.NodeID, s Stream) error {
@@ -299,7 +301,7 @@ func (r *Registry) Unsubscribe(peerId discover.NodeID, s Stream) error {
 	}
 	log.Debug("Unsubscribe ", "peer", peerId, "stream", s)
 
-	if err := peer.Send(msg); err != nil {
+	if err := peer.Send(context.TODO(), msg); err != nil {
 		return err
 	}
 	return peer.removeClient(s)
@@ -320,11 +322,17 @@ func (r *Registry) Quit(peerId discover.NodeID, s Stream) error {
 	}
 	log.Debug("Quit ", "peer", peerId, "stream", s)
 
-	return peer.Send(msg)
+	return peer.Send(context.TODO(), msg)
 }
 
-func (r *Registry) Retrieve(chunk *storage.Chunk) error {
+func (r *Registry) Retrieve(ctx context.Context, chunk *storage.Chunk) error {
-	return r.delivery.RequestFromPeers(chunk.Addr[:], r.skipCheck)
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"registry.retrieve")
+	defer sp.Finish()
+
+	return r.delivery.RequestFromPeers(ctx, chunk.Addr[:], r.skipCheck)
 }
 
 func (r *Registry) NodeInfo() interface{} {
@@ -460,11 +468,11 @@ func (r *Registry) runProtocol(p *p2p.Peer, rw p2p.MsgReadWriter) error {
 }
 
 // HandleMsg is the message handler that delegates incoming messages
-func (p *Peer) HandleMsg(msg interface{}) error {
+func (p *Peer) HandleMsg(ctx context.Context, msg interface{}) error {
 	switch msg := msg.(type) {
 
 	case *SubscribeMsg:
-		return p.handleSubscribeMsg(msg)
+		return p.handleSubscribeMsg(ctx, msg)
 
 	case *SubscribeErrorMsg:
 		return p.handleSubscribeErrorMsg(msg)
@@ -473,22 +481,22 @@ func (p *Peer) HandleMsg(msg interface{}) error {
 		return p.handleUnsubscribeMsg(msg)
 
 	case *OfferedHashesMsg:
-		return p.handleOfferedHashesMsg(msg)
+		return p.handleOfferedHashesMsg(ctx, msg)
 
 	case *TakeoverProofMsg:
-		return p.handleTakeoverProofMsg(msg)
+		return p.handleTakeoverProofMsg(ctx, msg)
 
 	case *WantedHashesMsg:
-		return p.handleWantedHashesMsg(msg)
+		return p.handleWantedHashesMsg(ctx, msg)
 
 	case *ChunkDeliveryMsg:
-		return p.streamer.delivery.handleChunkDeliveryMsg(p, msg)
+		return p.streamer.delivery.handleChunkDeliveryMsg(ctx, p, msg)
 
 	case *RetrieveRequestMsg:
-		return p.streamer.delivery.handleRetrieveRequestMsg(p, msg)
+		return p.streamer.delivery.handleRetrieveRequestMsg(ctx, p, msg)
 
 	case *RequestSubscriptionMsg:
-		return p.handleRequestSubscription(msg)
+		return p.handleRequestSubscription(ctx, msg)
 
 	case *QuitMsg:
 		return p.handleQuitMsg(msg)
@@ -508,7 +516,7 @@ type server struct {
 // Server interface for outgoing peer Streamer
 type Server interface {
 	SetNextBatch(uint64, uint64) (hashes []byte, from uint64, to uint64, proof *HandoverProof, err error)
-	GetData([]byte) ([]byte, error)
+	GetData(context.Context, []byte) ([]byte, error)
 	Close()
 }
 
@@ -551,7 +559,7 @@ func (c client) NextInterval() (start, end uint64, err error) {
 
 // Client interface for incoming peer Streamer
 type Client interface {
-	NeedData([]byte) func()
+	NeedData(context.Context, []byte) func()
 	BatchDone(Stream, uint64, []byte, []byte) func() (*TakeoverProof, error)
 	Close()
 }
@@ -588,7 +596,7 @@ func (c *client) batchDone(p *Peer, req *OfferedHashesMsg, hashes []byte) error
 		if err != nil {
 			return err
 		}
-		if err := p.SendPriority(tp, c.priority); err != nil {
+		if err := p.SendPriority(context.TODO(), tp, c.priority); err != nil {
 			return err
 		}
 		if c.to > 0 && tp.Takeover.End >= c.to {

swarm/network/stream/streamer_test.go

@@ -18,6 +18,7 @@ package stream
 
 import (
 	"bytes"
+	"context"
 	"testing"
 	"time"
 
@@ -79,7 +80,7 @@ func newTestClient(t string) *testClient {
 	}
 }
 
-func (self *testClient) NeedData(hash []byte) func() {
+func (self *testClient) NeedData(ctx context.Context, hash []byte) func() {
 	self.receivedHashes[string(hash)] = hash
 	if bytes.Equal(hash, hash0[:]) {
 		return func() {
@@ -114,7 +115,7 @@ func (self *testServer) SetNextBatch(from uint64, to uint64) ([]byte, uint64, ui
 	return make([]byte, HashSize), from + 1, to + 1, nil, nil
 }
 
-func (self *testServer) GetData([]byte) ([]byte, error) {
+func (self *testServer) GetData(context.Context, []byte) ([]byte, error) {
 	return nil, nil
 }
 

swarm/network/stream/syncer.go

@@ -17,6 +17,7 @@
 package stream
 
 import (
+	"context"
 	"math"
 	"strconv"
 	"time"
@@ -78,8 +79,8 @@ func (s *SwarmSyncerServer) Close() {
 }
 
 // GetSection retrieves the actual chunk from localstore
-func (s *SwarmSyncerServer) GetData(key []byte) ([]byte, error) {
+func (s *SwarmSyncerServer) GetData(ctx context.Context, key []byte) ([]byte, error) {
-	chunk, err := s.db.Get(storage.Address(key))
+	chunk, err := s.db.Get(ctx, storage.Address(key))
 	if err == storage.ErrFetching {
 		<-chunk.ReqC
 	} else if err != nil {
@@ -210,8 +211,8 @@ func RegisterSwarmSyncerClient(streamer *Registry, db *storage.DBAPI) {
 }
 
 // NeedData
-func (s *SwarmSyncerClient) NeedData(key []byte) (wait func()) {
+func (s *SwarmSyncerClient) NeedData(ctx context.Context, key []byte) (wait func()) {
-	chunk, _ := s.db.GetOrCreateRequest(key)
+	chunk, _ := s.db.GetOrCreateRequest(ctx, key)
 	// TODO: we may want to request from this peer anyway even if the request exists
 
 	// ignoreExistingRequest is temporary commented out until its functionality is verified.

swarm/network/stream/syncer_test.go

@@ -231,7 +231,7 @@ func testSyncBetweenNodes(t *testing.T, nodes, conns, chunkCount int, skipCheck
 		for j := i; j < nodes; j++ {
 			total += len(hashes[j])
 			for _, key := range hashes[j] {
-				chunk, err := dbs[i].Get(key)
+				chunk, err := dbs[i].Get(ctx, key)
 				if err == storage.ErrFetching {
 					<-chunk.ReqC
 				} else if err != nil {

swarm/pss/ping.go

@@ -19,6 +19,7 @@
 package pss
 
 import (
+	"context"
 	"errors"
 	"time"
 
@@ -40,7 +41,7 @@ type Ping struct {
 	InC  chan bool // optional, report back to calling code
 }
 
-func (p *Ping) pingHandler(msg interface{}) error {
+func (p *Ping) pingHandler(ctx context.Context, msg interface{}) error {
 	var pingmsg *PingMsg
 	var ok bool
 	if pingmsg, ok = msg.(*PingMsg); !ok {
@@ -80,7 +81,7 @@ func NewPingProtocol(ping *Ping) *p2p.Protocol {
 				for {
 					select {
 					case ispong := <-ping.OutC:
-						pp.Send(&PingMsg{
+						pp.Send(context.TODO(), &PingMsg{
 							Created: time.Now(),
 							Pong:    ispong,
 						})

swarm/pss/pss.go

@@ -18,6 +18,7 @@ package pss
 
 import (
 	"bytes"
+	"context"
 	"crypto/ecdsa"
 	"crypto/rand"
 	"errors"
@@ -71,7 +72,7 @@ type senderPeer interface {
 	Info() *p2p.PeerInfo
 	ID() discover.NodeID
 	Address() []byte
-	Send(interface{}) error
+	Send(context.Context, interface{}) error
 }
 
 // per-key peer related information
@@ -344,7 +345,7 @@ func (p *Pss) getHandlers(topic Topic) map[*Handler]bool {
 // Check if address partially matches
 // If yes, it CAN be for us, and we process it
 // Only passes error to pss protocol handler if payload is not valid pssmsg
-func (p *Pss) handlePssMsg(msg interface{}) error {
+func (p *Pss) handlePssMsg(ctx context.Context, msg interface{}) error {
 	metrics.GetOrRegisterCounter("pss.handlepssmsg", nil).Inc(1)
 
 	pssmsg, ok := msg.(*PssMsg)
@@ -844,7 +845,7 @@ func (p *Pss) forward(msg *PssMsg) error {
 		p.fwdPoolMu.RUnlock()
 
 		// attempt to send the message
-		err := pp.Send(msg)
+		err := pp.Send(context.TODO(), msg)
 		if err != nil {
 			metrics.GetOrRegisterCounter("pss.pp.send.error", nil).Inc(1)
 			log.Error(err.Error())

swarm/pss/pss_test.go

@@ -334,7 +334,7 @@ func TestHandlerConditions(t *testing.T) {
 			Data:  []byte{0x66, 0x6f, 0x6f},
 		},
 	}
-	if err := ps.handlePssMsg(msg); err != nil {
+	if err := ps.handlePssMsg(context.TODO(), msg); err != nil {
 		t.Fatal(err.Error())
 	}
 	tmr := time.NewTimer(time.Millisecond * 100)
@@ -351,7 +351,7 @@ func TestHandlerConditions(t *testing.T) {
 	// message should pass and queue due to partial length
 	msg.To = addr[0:1]
 	msg.Payload.Data = []byte{0x78, 0x79, 0x80, 0x80, 0x79}
-	if err := ps.handlePssMsg(msg); err != nil {
+	if err := ps.handlePssMsg(context.TODO(), msg); err != nil {
 		t.Fatal(err.Error())
 	}
 	tmr.Reset(time.Millisecond * 100)
@@ -374,7 +374,7 @@ func TestHandlerConditions(t *testing.T) {
 
 	// full address mismatch should put message in queue
 	msg.To[0] = 0xff
-	if err := ps.handlePssMsg(msg); err != nil {
+	if err := ps.handlePssMsg(context.TODO(), msg); err != nil {
 		t.Fatal(err.Error())
 	}
 	tmr.Reset(time.Millisecond * 10)
@@ -397,7 +397,7 @@ func TestHandlerConditions(t *testing.T) {
 
 	// expired message should be dropped
 	msg.Expire = uint32(time.Now().Add(-time.Second).Unix())
-	if err := ps.handlePssMsg(msg); err != nil {
+	if err := ps.handlePssMsg(context.TODO(), msg); err != nil {
 		t.Fatal(err.Error())
 	}
 	tmr.Reset(time.Millisecond * 10)
@@ -417,7 +417,7 @@ func TestHandlerConditions(t *testing.T) {
 	}{
 		pssMsg: &PssMsg{},
 	}
-	if err := ps.handlePssMsg(fckedupmsg); err == nil {
+	if err := ps.handlePssMsg(context.TODO(), fckedupmsg); err == nil {
 		t.Fatalf("expected error from processMsg but error nil")
 	}
 
@@ -427,7 +427,7 @@ func TestHandlerConditions(t *testing.T) {
 		ps.outbox <- msg
 	}
 	msg.Payload.Data = []byte{0x62, 0x61, 0x72}
-	err = ps.handlePssMsg(msg)
+	err = ps.handlePssMsg(context.TODO(), msg)
 	if err == nil {
 		t.Fatal("expected error when mailbox full, but was nil")
 	}

swarm/spancontext/spancontext.go

@@ -0,0 +1,49 @@
+package spancontext
+
+import (
+	"context"
+
+	opentracing "github.com/opentracing/opentracing-go"
+)
+
+func WithContext(ctx context.Context, sctx opentracing.SpanContext) context.Context {
+	return context.WithValue(ctx, "span_context", sctx)
+}
+
+func FromContext(ctx context.Context) opentracing.SpanContext {
+	sctx, ok := ctx.Value("span_context").(opentracing.SpanContext)
+	if ok {
+		return sctx
+	}
+
+	return nil
+}
+
+func StartSpan(ctx context.Context, name string) (context.Context, opentracing.Span) {
+	tracer := opentracing.GlobalTracer()
+
+	sctx := FromContext(ctx)
+
+	var sp opentracing.Span
+	if sctx != nil {
+		sp = tracer.StartSpan(
+			name,
+			opentracing.ChildOf(sctx))
+	} else {
+		sp = tracer.StartSpan(name)
+	}
+
+	nctx := context.WithValue(ctx, "span_context", sp.Context())
+
+	return nctx, sp
+}
+
+func StartSpanFrom(name string, sctx opentracing.SpanContext) opentracing.Span {
+	tracer := opentracing.GlobalTracer()
+
+	sp := tracer.StartSpan(
+		name,
+		opentracing.ChildOf(sctx))
+
+	return sp
+}

swarm/storage/chunker.go

@@ -26,6 +26,9 @@ import (
 
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/swarm/log"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
+	opentracing "github.com/opentracing/opentracing-go"
+	olog "github.com/opentracing/opentracing-go/log"
 )
 
 /*
@@ -93,9 +96,12 @@ type JoinerParams struct {
 	getter Getter
 	// TODO: there is a bug, so depth can only be 0 today, see: https://github.com/ethersphere/go-ethereum/issues/344
 	depth int
+	ctx   context.Context
 }
 
 type TreeChunker struct {
+	ctx context.Context
+
 	branches int64
 	hashFunc SwarmHasher
 	dataSize int64
@@ -136,6 +142,7 @@ func TreeJoin(ctx context.Context, addr Address, getter Getter, depth int) *Lazy
 		addr:   addr,
 		getter: getter,
 		depth:  depth,
+		ctx:    ctx,
 	}
 
 	return NewTreeJoiner(jp).Join(ctx)
@@ -174,6 +181,8 @@ func NewTreeJoiner(params *JoinerParams) *TreeChunker {
 	tc.errC = make(chan error)
 	tc.quitC = make(chan bool)
 
+	tc.ctx = params.ctx
+
 	return tc
 }
 
@@ -351,7 +360,7 @@ func (tc *TreeChunker) runWorker() {
 					return
 				}
 
-				h, err := tc.putter.Put(job.chunk)
+				h, err := tc.putter.Put(tc.ctx, job.chunk)
 				if err != nil {
 					tc.errC <- err
 					return
@@ -371,6 +380,7 @@ func (tc *TreeChunker) Append() (Address, func(), error) {
 
 // LazyChunkReader implements LazySectionReader
 type LazyChunkReader struct {
+	Ctx       context.Context
 	key       Address // root key
 	chunkData ChunkData
 	off       int64 // offset
@@ -389,16 +399,28 @@ func (tc *TreeChunker) Join(ctx context.Context) *LazyChunkReader {
 		hashSize:  tc.hashSize,
 		depth:     tc.depth,
 		getter:    tc.getter,
+		Ctx:       tc.ctx,
 	}
 }
 
+func (r *LazyChunkReader) Context() context.Context {
+	return r.Ctx
+}
+
 // Size is meant to be called on the LazySectionReader
-func (r *LazyChunkReader) Size(quitC chan bool) (n int64, err error) {
+func (r *LazyChunkReader) Size(ctx context.Context, quitC chan bool) (n int64, err error) {
 	metrics.GetOrRegisterCounter("lazychunkreader.size", nil).Inc(1)
 
+	var sp opentracing.Span
+	var cctx context.Context
+	cctx, sp = spancontext.StartSpan(
+		ctx,
+		"lcr.size")
+	defer sp.Finish()
+
 	log.Debug("lazychunkreader.size", "key", r.key)
 	if r.chunkData == nil {
-		chunkData, err := r.getter.Get(Reference(r.key))
+		chunkData, err := r.getter.Get(cctx, Reference(r.key))
 		if err != nil {
 			return 0, err
 		}
@@ -421,12 +443,25 @@ func (r *LazyChunkReader) Size(quitC chan bool) (n int64, err error) {
 func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 	metrics.GetOrRegisterCounter("lazychunkreader.readat", nil).Inc(1)
 
+	var sp opentracing.Span
+	var cctx context.Context
+	cctx, sp = spancontext.StartSpan(
+		r.Ctx,
+		"lcr.read")
+	defer sp.Finish()
+
+	defer func() {
+		sp.LogFields(
+			olog.Int("off", int(off)),
+			olog.Int("read", read))
+	}()
+
 	// this is correct, a swarm doc cannot be zero length, so no EOF is expected
 	if len(b) == 0 {
 		return 0, nil
 	}
 	quitC := make(chan bool)
-	size, err := r.Size(quitC)
+	size, err := r.Size(cctx, quitC)
 	if err != nil {
 		log.Error("lazychunkreader.readat.size", "size", size, "err", err)
 		return 0, err
@@ -449,7 +484,7 @@ func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 		length *= r.chunkSize
 	}
 	wg.Add(1)
-	go r.join(b, off, off+length, depth, treeSize/r.branches, r.chunkData, &wg, errC, quitC)
+	go r.join(cctx, b, off, off+length, depth, treeSize/r.branches, r.chunkData, &wg, errC, quitC)
 	go func() {
 		wg.Wait()
 		close(errC)
@@ -467,7 +502,7 @@ func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 	return len(b), nil
 }
 
-func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeSize int64, chunkData ChunkData, parentWg *sync.WaitGroup, errC chan error, quitC chan bool) {
+func (r *LazyChunkReader) join(ctx context.Context, b []byte, off int64, eoff int64, depth int, treeSize int64, chunkData ChunkData, parentWg *sync.WaitGroup, errC chan error, quitC chan bool) {
 	defer parentWg.Done()
 	// find appropriate block level
 	for chunkData.Size() < treeSize && depth > r.depth {
@@ -514,7 +549,7 @@ func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeS
 		wg.Add(1)
 		go func(j int64) {
 			childKey := chunkData[8+j*r.hashSize : 8+(j+1)*r.hashSize]
-			chunkData, err := r.getter.Get(Reference(childKey))
+			chunkData, err := r.getter.Get(ctx, Reference(childKey))
 			if err != nil {
 				log.Error("lazychunkreader.join", "key", fmt.Sprintf("%x", childKey), "err", err)
 				select {
@@ -533,7 +568,7 @@ func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeS
 			if soff < off {
 				soff = off
 			}
-			r.join(b[soff-off:seoff-off], soff-roff, seoff-roff, depth-1, treeSize/r.branches, chunkData, wg, errC, quitC)
+			r.join(ctx, b[soff-off:seoff-off], soff-roff, seoff-roff, depth-1, treeSize/r.branches, chunkData, wg, errC, quitC)
 		}(i)
 	} //for
 }
@@ -570,7 +605,7 @@ func (r *LazyChunkReader) Seek(offset int64, whence int) (int64, error) {
 		offset += r.off
 	case 2:
 		if r.chunkData == nil { //seek from the end requires rootchunk for size. call Size first
-			_, err := r.Size(nil)
+			_, err := r.Size(context.TODO(), nil)
 			if err != nil {
 				return 0, fmt.Errorf("can't get size: %v", err)
 			}

swarm/storage/chunker_test.go

@@ -50,11 +50,11 @@ type fakeChunkStore struct {
 }
 
 // Put doesn't store anything it is just here to implement ChunkStore
-func (f *fakeChunkStore) Put(*Chunk) {
+func (f *fakeChunkStore) Put(context.Context, *Chunk) {
 }
 
 // Gut doesn't store anything it is just here to implement ChunkStore
-func (f *fakeChunkStore) Get(Address) (*Chunk, error) {
+func (f *fakeChunkStore) Get(context.Context, Address) (*Chunk, error) {
 	return nil, errors.New("FakeChunkStore doesn't support Get")
 }
 
@@ -281,7 +281,7 @@ func TestRandomBrokenData(t *testing.T) {
 }
 
 func benchReadAll(reader LazySectionReader) {
-	size, _ := reader.Size(nil)
+	size, _ := reader.Size(context.TODO(), nil)
 	output := make([]byte, 1000)
 	for pos := int64(0); pos < size; pos += 1000 {
 		reader.ReadAt(output, pos)

swarm/storage/chunkstore.go

@@ -16,7 +16,10 @@
 
 package storage
 
-import "sync"
+import (
+	"context"
+	"sync"
+)
 
 /*
 ChunkStore interface is implemented by :
@@ -28,8 +31,8 @@ ChunkStore interface is implemented by :
 - FakeChunkStore: dummy store which doesn't store anything just implements the interface
 */
 type ChunkStore interface {
-	Put(*Chunk) // effectively there is no error even if there is an error
+	Put(context.Context, *Chunk) // effectively there is no error even if there is an error
-	Get(Address) (*Chunk, error)
+	Get(context.Context, Address) (*Chunk, error)
 	Close()
 }
 
@@ -45,14 +48,14 @@ func NewMapChunkStore() *MapChunkStore {
 	}
 }
 
-func (m *MapChunkStore) Put(chunk *Chunk) {
+func (m *MapChunkStore) Put(ctx context.Context, chunk *Chunk) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	m.chunks[chunk.Addr.Hex()] = chunk
 	chunk.markAsStored()
 }
 
-func (m *MapChunkStore) Get(addr Address) (*Chunk, error) {
+func (m *MapChunkStore) Get(ctx context.Context, addr Address) (*Chunk, error) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
 	chunk := m.chunks[addr.Hex()]

swarm/storage/common.go

@@ -16,6 +16,7 @@
 package storage
 
 import (
+	"context"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/swarm/log"
@@ -37,7 +38,7 @@ func PutChunks(store *LocalStore, chunks ...*Chunk) {
 		}
 	}()
 	for _, c := range chunks {
-		go store.Put(c)
+		go store.Put(context.TODO(), c)
 	}
 	wg.Wait()
 }

swarm/storage/common_test.go

@@ -18,6 +18,7 @@ package storage
 
 import (
 	"bytes"
+	"context"
 	"crypto/rand"
 	"flag"
 	"fmt"
@@ -69,7 +70,7 @@ func mput(store ChunkStore, processors int, n int, f func(i int64) *Chunk) (hs [
 			for chunk := range c {
 				wg.Add(1)
 				chunk := chunk
-				store.Put(chunk)
+				store.Put(context.TODO(), chunk)
 				go func() {
 					defer wg.Done()
 					<-chunk.dbStoredC
@@ -103,7 +104,7 @@ func mget(store ChunkStore, hs []Address, f func(h Address, chunk *Chunk) error)
 	for _, k := range hs {
 		go func(h Address) {
 			defer wg.Done()
-			chunk, err := store.Get(h)
+			chunk, err := store.Get(context.TODO(), h)
 			if err != nil {
 				errc <- err
 				return

swarm/storage/dbapi.go

@@ -16,6 +16,8 @@
 
 package storage
 
+import "context"
+
 // wrapper of db-s to provide mockable custom local chunk store access to syncer
 type DBAPI struct {
 	db  *LDBStore
@@ -27,8 +29,8 @@ func NewDBAPI(loc *LocalStore) *DBAPI {
 }
 
 // to obtain the chunks from address or request db entry only
-func (d *DBAPI) Get(addr Address) (*Chunk, error) {
+func (d *DBAPI) Get(ctx context.Context, addr Address) (*Chunk, error) {
-	return d.loc.Get(addr)
+	return d.loc.Get(ctx, addr)
 }
 
 // current storage counter of chunk db
@@ -42,11 +44,11 @@ func (d *DBAPI) Iterator(from uint64, to uint64, po uint8, f func(Address, uint6
 }
 
 // to obtain the chunks from address or request db entry only
-func (d *DBAPI) GetOrCreateRequest(addr Address) (*Chunk, bool) {
+func (d *DBAPI) GetOrCreateRequest(ctx context.Context, addr Address) (*Chunk, bool) {
-	return d.loc.GetOrCreateRequest(addr)
+	return d.loc.GetOrCreateRequest(ctx, addr)
 }
 
 // to obtain the chunks from key or request db entry only
-func (d *DBAPI) Put(chunk *Chunk) {
+func (d *DBAPI) Put(ctx context.Context, chunk *Chunk) {
-	d.loc.Put(chunk)
+	d.loc.Put(ctx, chunk)
 }

swarm/storage/hasherstore.go

@@ -74,7 +74,7 @@ func NewHasherStore(chunkStore ChunkStore, hashFunc SwarmHasher, toEncrypt bool)
 // Put stores the chunkData into the ChunkStore of the hasherStore and returns the reference.
 // If hasherStore has a chunkEncryption object, the data will be encrypted.
 // Asynchronous function, the data will not necessarily be stored when it returns.
-func (h *hasherStore) Put(chunkData ChunkData) (Reference, error) {
+func (h *hasherStore) Put(ctx context.Context, chunkData ChunkData) (Reference, error) {
 	c := chunkData
 	size := chunkData.Size()
 	var encryptionKey encryption.Key
@@ -87,7 +87,7 @@ func (h *hasherStore) Put(chunkData ChunkData) (Reference, error) {
 	}
 	chunk := h.createChunk(c, size)
 
-	h.storeChunk(chunk)
+	h.storeChunk(ctx, chunk)
 
 	return Reference(append(chunk.Addr, encryptionKey...)), nil
 }
@@ -95,14 +95,14 @@ func (h *hasherStore) Put(chunkData ChunkData) (Reference, error) {
 // Get returns data of the chunk with the given reference (retrieved from the ChunkStore of hasherStore).
 // If the data is encrypted and the reference contains an encryption key, it will be decrypted before
 // return.
-func (h *hasherStore) Get(ref Reference) (ChunkData, error) {
+func (h *hasherStore) Get(ctx context.Context, ref Reference) (ChunkData, error) {
 	key, encryptionKey, err := parseReference(ref, h.hashSize)
 	if err != nil {
 		return nil, err
 	}
 	toDecrypt := (encryptionKey != nil)
 
-	chunk, err := h.store.Get(key)
+	chunk, err := h.store.Get(ctx, key)
 	if err != nil {
 		return nil, err
 	}
@@ -207,13 +207,13 @@ func (h *hasherStore) RefSize() int64 {
 	return h.refSize
 }
 
-func (h *hasherStore) storeChunk(chunk *Chunk) {
+func (h *hasherStore) storeChunk(ctx context.Context, chunk *Chunk) {
 	h.wg.Add(1)
 	go func() {
 		<-chunk.dbStoredC
 		h.wg.Done()
 	}()
-	h.store.Put(chunk)
+	h.store.Put(ctx, chunk)
 }
 
 func parseReference(ref Reference, hashSize int) (Address, encryption.Key, error) {

swarm/storage/hasherstore_test.go

@@ -47,13 +47,13 @@ func TestHasherStore(t *testing.T) {
 
 		// Put two random chunks into the hasherStore
 		chunkData1 := GenerateRandomChunk(int64(tt.chunkLength)).SData
-		key1, err := hasherStore.Put(chunkData1)
+		key1, err := hasherStore.Put(context.TODO(), chunkData1)
 		if err != nil {
 			t.Fatalf("Expected no error got \"%v\"", err)
 		}
 
 		chunkData2 := GenerateRandomChunk(int64(tt.chunkLength)).SData
-		key2, err := hasherStore.Put(chunkData2)
+		key2, err := hasherStore.Put(context.TODO(), chunkData2)
 		if err != nil {
 			t.Fatalf("Expected no error got \"%v\"", err)
 		}
@@ -67,7 +67,7 @@ func TestHasherStore(t *testing.T) {
 		}
 
 		// Get the first chunk
-		retrievedChunkData1, err := hasherStore.Get(key1)
+		retrievedChunkData1, err := hasherStore.Get(context.TODO(), key1)
 		if err != nil {
 			t.Fatalf("Expected no error, got \"%v\"", err)
 		}
@@ -78,7 +78,7 @@ func TestHasherStore(t *testing.T) {
 		}
 
 		// Get the second chunk
-		retrievedChunkData2, err := hasherStore.Get(key2)
+		retrievedChunkData2, err := hasherStore.Get(context.TODO(), key2)
 		if err != nil {
 			t.Fatalf("Expected no error, got \"%v\"", err)
 		}
@@ -105,7 +105,7 @@ func TestHasherStore(t *testing.T) {
 		}
 
 		// Check if chunk data in store is encrypted or not
-		chunkInStore, err := chunkStore.Get(hash1)
+		chunkInStore, err := chunkStore.Get(context.TODO(), hash1)
 		if err != nil {
 			t.Fatalf("Expected no error got \"%v\"", err)
 		}

swarm/storage/ldbstore.go

@@ -25,6 +25,7 @@ package storage
 import (
 	"archive/tar"
 	"bytes"
+	"context"
 	"encoding/binary"
 	"encoding/hex"
 	"fmt"
@@ -370,7 +371,7 @@ func (s *LDBStore) Import(in io.Reader) (int64, error) {
 		key := Address(keybytes)
 		chunk := NewChunk(key, nil)
 		chunk.SData = data[32:]
-		s.Put(chunk)
+		s.Put(context.TODO(), chunk)
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
@@ -499,7 +500,7 @@ func (s *LDBStore) CurrentStorageIndex() uint64 {
 	return s.dataIdx
 }
 
-func (s *LDBStore) Put(chunk *Chunk) {
+func (s *LDBStore) Put(ctx context.Context, chunk *Chunk) {
 	metrics.GetOrRegisterCounter("ldbstore.put", nil).Inc(1)
 	log.Trace("ldbstore.put", "key", chunk.Addr)
 
@@ -639,7 +640,7 @@ func (s *LDBStore) tryAccessIdx(ikey []byte, index *dpaDBIndex) bool {
 	return true
 }
 
-func (s *LDBStore) Get(addr Address) (chunk *Chunk, err error) {
+func (s *LDBStore) Get(ctx context.Context, addr Address) (chunk *Chunk, err error) {
 	metrics.GetOrRegisterCounter("ldbstore.get", nil).Inc(1)
 	log.Trace("ldbstore.get", "key", addr)
 

swarm/storage/ldbstore_test.go

@@ -18,6 +18,7 @@ package storage
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -157,7 +158,7 @@ func testDbStoreNotFound(t *testing.T, mock bool) {
 		t.Fatalf("init dbStore failed: %v", err)
 	}
 
-	_, err = db.Get(ZeroAddr)
+	_, err = db.Get(context.TODO(), ZeroAddr)
 	if err != ErrChunkNotFound {
 		t.Errorf("Expected ErrChunkNotFound, got %v", err)
 	}
@@ -188,7 +189,7 @@ func testIterator(t *testing.T, mock bool) {
 	wg := &sync.WaitGroup{}
 	wg.Add(len(chunks))
 	for i = 0; i < len(chunks); i++ {
-		db.Put(chunks[i])
+		db.Put(context.TODO(), chunks[i])
 		chunkkeys[i] = chunks[i].Addr
 		j := i
 		go func() {
@@ -299,7 +300,7 @@ func TestLDBStoreWithoutCollectGarbage(t *testing.T) {
 	}
 
 	for i := 0; i < n; i++ {
-		go ldb.Put(chunks[i])
+		go ldb.Put(context.TODO(), chunks[i])
 	}
 
 	// wait for all chunks to be stored
@@ -310,7 +311,7 @@ func TestLDBStoreWithoutCollectGarbage(t *testing.T) {
 	log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
 
 	for i := 0; i < n; i++ {
-		ret, err := ldb.Get(chunks[i].Addr)
+		ret, err := ldb.Get(context.TODO(), chunks[i].Addr)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -349,7 +350,7 @@ func TestLDBStoreCollectGarbage(t *testing.T) {
 	}
 
 	for i := 0; i < n; i++ {
-		ldb.Put(chunks[i])
+		ldb.Put(context.TODO(), chunks[i])
 	}
 
 	// wait for all chunks to be stored
@@ -364,7 +365,7 @@ func TestLDBStoreCollectGarbage(t *testing.T) {
 
 	var missing int
 	for i := 0; i < n; i++ {
-		ret, err := ldb.Get(chunks[i].Addr)
+		ret, err := ldb.Get(context.TODO(), chunks[i].Addr)
 		if err == ErrChunkNotFound || err == ldberrors.ErrNotFound {
 			missing++
 			continue
@@ -403,7 +404,7 @@ func TestLDBStoreAddRemove(t *testing.T) {
 	}
 
 	for i := 0; i < n; i++ {
-		go ldb.Put(chunks[i])
+		go ldb.Put(context.TODO(), chunks[i])
 	}
 
 	// wait for all chunks to be stored before continuing
@@ -428,7 +429,7 @@ func TestLDBStoreAddRemove(t *testing.T) {
 	log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
 
 	for i := 0; i < n; i++ {
-		ret, err := ldb.Get(chunks[i].Addr)
+		ret, err := ldb.Get(context.TODO(), chunks[i].Addr)
 
 		if i%2 == 0 {
 			// expect even chunks to be missing
@@ -465,7 +466,7 @@ func TestLDBStoreRemoveThenCollectGarbage(t *testing.T) {
 	}
 
 	for i := 0; i < n; i++ {
-		ldb.Put(chunks[i])
+		ldb.Put(context.TODO(), chunks[i])
 	}
 
 	// wait for all chunks to be stored before continuing
@@ -494,7 +495,7 @@ func TestLDBStoreRemoveThenCollectGarbage(t *testing.T) {
 	n = 10
 
 	for i := 0; i < n; i++ {
-		ldb.Put(chunks[i])
+		ldb.Put(context.TODO(), chunks[i])
 	}
 
 	// wait for all chunks to be stored before continuing
@@ -504,14 +505,14 @@ func TestLDBStoreRemoveThenCollectGarbage(t *testing.T) {
 
 	// expect for first chunk to be missing, because it has the smallest access value
 	idx := 0
-	ret, err := ldb.Get(chunks[idx].Addr)
+	ret, err := ldb.Get(context.TODO(), chunks[idx].Addr)
 	if err == nil || ret != nil {
 		t.Fatal("expected first chunk to be missing, but got no error")
 	}
 
 	// expect for last chunk to be present, as it has the largest access value
 	idx = 9
-	ret, err = ldb.Get(chunks[idx].Addr)
+	ret, err = ldb.Get(context.TODO(), chunks[idx].Addr)
 	if err != nil {
 		t.Fatalf("expected no error, but got %s", err)
 	}

swarm/storage/localstore.go

@@ -17,6 +17,7 @@
 package storage
 
 import (
+	"context"
 	"encoding/binary"
 	"fmt"
 	"path/filepath"
@@ -96,7 +97,7 @@ func NewTestLocalStoreForAddr(params *LocalStoreParams) (*LocalStore, error) {
 // when the chunk is stored in memstore.
 // After the LDBStore.Put, it is ensured that the MemStore
 // contains the chunk with the same data, but nil ReqC channel.
-func (ls *LocalStore) Put(chunk *Chunk) {
+func (ls *LocalStore) Put(ctx context.Context, chunk *Chunk) {
 	if l := len(chunk.SData); l < 9 {
 		log.Debug("incomplete chunk data", "addr", chunk.Addr, "length", l)
 		chunk.SetErrored(ErrChunkInvalid)
@@ -123,7 +124,7 @@ func (ls *LocalStore) Put(chunk *Chunk) {
 
 	chunk.Size = int64(binary.LittleEndian.Uint64(chunk.SData[0:8]))
 
-	memChunk, err := ls.memStore.Get(chunk.Addr)
+	memChunk, err := ls.memStore.Get(ctx, chunk.Addr)
 	switch err {
 	case nil:
 		if memChunk.ReqC == nil {
@@ -136,7 +137,7 @@ func (ls *LocalStore) Put(chunk *Chunk) {
 		return
 	}
 
-	ls.DbStore.Put(chunk)
+	ls.DbStore.Put(ctx, chunk)
 
 	// chunk is no longer a request, but a chunk with data, so replace it in memStore
 	newc := NewChunk(chunk.Addr, nil)
@@ -144,7 +145,7 @@ func (ls *LocalStore) Put(chunk *Chunk) {
 	newc.Size = chunk.Size
 	newc.dbStoredC = chunk.dbStoredC
 
-	ls.memStore.Put(newc)
+	ls.memStore.Put(ctx, newc)
 
 	if memChunk != nil && memChunk.ReqC != nil {
 		close(memChunk.ReqC)
@@ -155,15 +156,15 @@ func (ls *LocalStore) Put(chunk *Chunk) {
 // This method is blocking until the chunk is retrieved
 // so additional timeout may be needed to wrap this call if
 // ChunkStores are remote and can have long latency
-func (ls *LocalStore) Get(addr Address) (chunk *Chunk, err error) {
+func (ls *LocalStore) Get(ctx context.Context, addr Address) (chunk *Chunk, err error) {
 	ls.mu.Lock()
 	defer ls.mu.Unlock()
 
-	return ls.get(addr)
+	return ls.get(ctx, addr)
 }
 
-func (ls *LocalStore) get(addr Address) (chunk *Chunk, err error) {
+func (ls *LocalStore) get(ctx context.Context, addr Address) (chunk *Chunk, err error) {
-	chunk, err = ls.memStore.Get(addr)
+	chunk, err = ls.memStore.Get(ctx, addr)
 	if err == nil {
 		if chunk.ReqC != nil {
 			select {
@@ -177,25 +178,25 @@ func (ls *LocalStore) get(addr Address) (chunk *Chunk, err error) {
 		return
 	}
 	metrics.GetOrRegisterCounter("localstore.get.cachemiss", nil).Inc(1)
-	chunk, err = ls.DbStore.Get(addr)
+	chunk, err = ls.DbStore.Get(ctx, addr)
 	if err != nil {
 		metrics.GetOrRegisterCounter("localstore.get.error", nil).Inc(1)
 		return
 	}
 	chunk.Size = int64(binary.LittleEndian.Uint64(chunk.SData[0:8]))
-	ls.memStore.Put(chunk)
+	ls.memStore.Put(ctx, chunk)
 	return
 }
 
 // retrieve logic common for local and network chunk retrieval requests
-func (ls *LocalStore) GetOrCreateRequest(addr Address) (chunk *Chunk, created bool) {
+func (ls *LocalStore) GetOrCreateRequest(ctx context.Context, addr Address) (chunk *Chunk, created bool) {
 	metrics.GetOrRegisterCounter("localstore.getorcreaterequest", nil).Inc(1)
 
 	ls.mu.Lock()
 	defer ls.mu.Unlock()
 
 	var err error
-	chunk, err = ls.get(addr)
+	chunk, err = ls.get(ctx, addr)
 	if err == nil && chunk.GetErrored() == nil {
 		metrics.GetOrRegisterCounter("localstore.getorcreaterequest.hit", nil).Inc(1)
 		log.Trace(fmt.Sprintf("LocalStore.GetOrRetrieve: %v found locally", addr))
@@ -210,7 +211,7 @@ func (ls *LocalStore) GetOrCreateRequest(addr Address) (chunk *Chunk, created bo
 	metrics.GetOrRegisterCounter("localstore.getorcreaterequest.miss", nil).Inc(1)
 	log.Trace(fmt.Sprintf("LocalStore.GetOrRetrieve: %v not found locally. open new request", addr))
 	chunk = NewChunk(addr, make(chan bool))
-	ls.memStore.Put(chunk)
+	ls.memStore.Put(ctx, chunk)
 	return chunk, true
 }
 

swarm/storage/memstore.go

@@ -19,6 +19,7 @@
 package storage
 
 import (
+	"context"
 	"sync"
 
 	lru "github.com/hashicorp/golang-lru"
@@ -68,7 +69,7 @@ func NewMemStore(params *StoreParams, _ *LDBStore) (m *MemStore) {
 	}
 }
 
-func (m *MemStore) Get(addr Address) (*Chunk, error) {
+func (m *MemStore) Get(ctx context.Context, addr Address) (*Chunk, error) {
 	if m.disabled {
 		return nil, ErrChunkNotFound
 	}
@@ -90,7 +91,7 @@ func (m *MemStore) Get(addr Address) (*Chunk, error) {
 	return c.(*Chunk), nil
 }
 
-func (m *MemStore) Put(c *Chunk) {
+func (m *MemStore) Put(ctx context.Context, c *Chunk) {
 	if m.disabled {
 		return
 	}

swarm/storage/memstore_test.go

@@ -17,6 +17,7 @@
 package storage
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/binary"
 	"io/ioutil"
@@ -72,7 +73,7 @@ func TestMemStoreNotFound(t *testing.T) {
 	m := newTestMemStore()
 	defer m.Close()
 
-	_, err := m.Get(ZeroAddr)
+	_, err := m.Get(context.TODO(), ZeroAddr)
 	if err != ErrChunkNotFound {
 		t.Errorf("Expected ErrChunkNotFound, got %v", err)
 	}
@@ -187,8 +188,8 @@ func TestMemStoreAndLDBStore(t *testing.T) {
 		}
 
 		for i := 0; i < tt.n; i++ {
-			go ldb.Put(chunks[i])
+			go ldb.Put(context.TODO(), chunks[i])
-			memStore.Put(chunks[i])
+			memStore.Put(context.TODO(), chunks[i])
 
 			if got := memStore.cache.Len(); got > cacheCap {
 				t.Fatalf("expected to get cache capacity less than %v, but got %v", cacheCap, got)
@@ -200,10 +201,10 @@ func TestMemStoreAndLDBStore(t *testing.T) {
 		}
 
 		for i := 0; i < tt.n; i++ {
-			_, err := memStore.Get(chunks[i].Addr)
+			_, err := memStore.Get(context.TODO(), chunks[i].Addr)
 			if err != nil {
 				if err == ErrChunkNotFound {
-					_, err := ldb.Get(chunks[i].Addr)
+					_, err := ldb.Get(context.TODO(), chunks[i].Addr)
 					if err != nil {
 						t.Fatalf("couldn't get chunk %v from ldb, got error: %v", i, err)
 					}

swarm/storage/mru/resource.go

@@ -125,6 +125,10 @@ type resource struct {
 	updated    time.Time
 }
 
+func (r *resource) Context() context.Context {
+	return context.TODO()
+}
+
 // TODO Expire content after a defined period (to force resync)
 func (r *resource) isSynced() bool {
 	return !r.updated.IsZero()
@@ -134,7 +138,7 @@ func (r *resource) NameHash() common.Hash {
 	return r.nameHash
 }
 
-func (r *resource) Size(chan bool) (int64, error) {
+func (r *resource) Size(context.Context, chan bool) (int64, error) {
 	if !r.isSynced() {
 		return 0, NewError(ErrNotSynced, "Not synced")
 	}
@@ -413,7 +417,7 @@ func (h *Handler) New(ctx context.Context, name string, frequency uint64) (stora
 
 	chunk := h.newMetaChunk(name, currentblock, frequency)
 
-	h.chunkStore.Put(chunk)
+	h.chunkStore.Put(ctx, chunk)
 	log.Debug("new resource", "name", name, "key", nameHash, "startBlock", currentblock, "frequency", frequency)
 
 	// create the internal index for the resource and populate it with the data of the first version
@@ -593,7 +597,7 @@ func (h *Handler) lookup(rsrc *resource, period uint32, version uint32, refresh
 			return nil, NewError(ErrPeriodDepth, fmt.Sprintf("Lookup exceeded max period hops (%d)", maxLookup.Max))
 		}
 		key := h.resourceHash(period, version, rsrc.nameHash)
-		chunk, err := h.chunkStore.GetWithTimeout(key, defaultRetrieveTimeout)
+		chunk, err := h.chunkStore.GetWithTimeout(context.TODO(), key, defaultRetrieveTimeout)
 		if err == nil {
 			if specificversion {
 				return h.updateIndex(rsrc, chunk)
@@ -603,7 +607,7 @@ func (h *Handler) lookup(rsrc *resource, period uint32, version uint32, refresh
 			for {
 				newversion := version + 1
 				key := h.resourceHash(period, newversion, rsrc.nameHash)
-				newchunk, err := h.chunkStore.GetWithTimeout(key, defaultRetrieveTimeout)
+				newchunk, err := h.chunkStore.GetWithTimeout(context.TODO(), key, defaultRetrieveTimeout)
 				if err != nil {
 					return h.updateIndex(rsrc, chunk)
 				}
@@ -621,8 +625,8 @@ func (h *Handler) lookup(rsrc *resource, period uint32, version uint32, refresh
 
 // Retrieves a resource metadata chunk and creates/updates the index entry for it
 // with the resulting metadata
-func (h *Handler) Load(addr storage.Address) (*resource, error) {
+func (h *Handler) Load(ctx context.Context, addr storage.Address) (*resource, error) {
-	chunk, err := h.chunkStore.GetWithTimeout(addr, defaultRetrieveTimeout)
+	chunk, err := h.chunkStore.GetWithTimeout(ctx, addr, defaultRetrieveTimeout)
 	if err != nil {
 		return nil, NewError(ErrNotFound, err.Error())
 	}
@@ -890,7 +894,7 @@ func (h *Handler) update(ctx context.Context, name string, data []byte, multihas
 	chunk := newUpdateChunk(key, signature, nextperiod, version, name, data, datalength)
 
 	// send the chunk
-	h.chunkStore.Put(chunk)
+	h.chunkStore.Put(ctx, chunk)
 	log.Trace("resource update", "name", name, "key", key, "currentblock", currentblock, "lastperiod", nextperiod, "version", version, "data", chunk.SData, "multihash", multihash)
 
 	// update our resources map entry and return the new key

swarm/storage/mru/resource_test.go

@@ -182,7 +182,7 @@ func TestHandler(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	chunk, err := rh.chunkStore.Get(storage.Address(rootChunkKey))
+	chunk, err := rh.chunkStore.Get(context.TODO(), storage.Address(rootChunkKey))
 	if err != nil {
 		t.Fatal(err)
 	} else if len(chunk.SData) < 16 {
@@ -256,7 +256,7 @@ func TestHandler(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	rsrc2, err := rh2.Load(rootChunkKey)
+	rsrc2, err := rh2.Load(context.TODO(), rootChunkKey)
 	_, err = rh2.LookupLatest(ctx, nameHash, true, nil)
 	if err != nil {
 		t.Fatal(err)
@@ -754,7 +754,7 @@ func newTestSigner() (*GenericSigner, error) {
 }
 
 func getUpdateDirect(rh *Handler, addr storage.Address) ([]byte, error) {
-	chunk, err := rh.chunkStore.Get(addr)
+	chunk, err := rh.chunkStore.Get(context.TODO(), addr)
 	if err != nil {
 		return nil, err
 	}

swarm/storage/netstore.go

@@ -17,9 +17,12 @@
 package storage
 
 import (
+	"context"
 	"time"
 
 	"github.com/ethereum/go-ethereum/swarm/log"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
+	opentracing "github.com/opentracing/opentracing-go"
 )
 
 var (
@@ -43,10 +46,10 @@ var (
 // access by calling network is blocking with a timeout
 type NetStore struct {
 	localStore *LocalStore
-	retrieve   func(chunk *Chunk) error
+	retrieve   func(ctx context.Context, chunk *Chunk) error
 }
 
-func NewNetStore(localStore *LocalStore, retrieve func(chunk *Chunk) error) *NetStore {
+func NewNetStore(localStore *LocalStore, retrieve func(ctx context.Context, chunk *Chunk) error) *NetStore {
 	return &NetStore{localStore, retrieve}
 }
 
@@ -56,7 +59,14 @@ func NewNetStore(localStore *LocalStore, retrieve func(chunk *Chunk) error) *Net
 // Get uses get method to retrieve request, but retries if the
 // ErrChunkNotFound is returned by get, until the netStoreRetryTimeout
 // is reached.
-func (ns *NetStore) Get(addr Address) (chunk *Chunk, err error) {
+func (ns *NetStore) Get(ctx context.Context, addr Address) (chunk *Chunk, err error) {
+
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"netstore.get.global")
+	defer sp.Finish()
+
 	timer := time.NewTimer(netStoreRetryTimeout)
 	defer timer.Stop()
 
@@ -84,7 +94,7 @@ func (ns *NetStore) Get(addr Address) (chunk *Chunk, err error) {
 		defer limiter.Stop()
 
 		for {
-			chunk, err := ns.get(addr, 0)
+			chunk, err := ns.get(ctx, addr, 0)
 			if err != ErrChunkNotFound {
 				// break retry only if the error is nil
 				// or other error then ErrChunkNotFound
@@ -122,16 +132,23 @@ func (ns *NetStore) Get(addr Address) (chunk *Chunk, err error) {
 }
 
 // GetWithTimeout makes a single retrieval attempt for a chunk with a explicit timeout parameter
-func (ns *NetStore) GetWithTimeout(addr Address, timeout time.Duration) (chunk *Chunk, err error) {
+func (ns *NetStore) GetWithTimeout(ctx context.Context, addr Address, timeout time.Duration) (chunk *Chunk, err error) {
-	return ns.get(addr, timeout)
+	return ns.get(ctx, addr, timeout)
 }
 
-func (ns *NetStore) get(addr Address, timeout time.Duration) (chunk *Chunk, err error) {
+func (ns *NetStore) get(ctx context.Context, addr Address, timeout time.Duration) (chunk *Chunk, err error) {
 	if timeout == 0 {
 		timeout = searchTimeout
 	}
+
+	var sp opentracing.Span
+	ctx, sp = spancontext.StartSpan(
+		ctx,
+		"netstore.get")
+	defer sp.Finish()
+
 	if ns.retrieve == nil {
-		chunk, err = ns.localStore.Get(addr)
+		chunk, err = ns.localStore.Get(ctx, addr)
 		if err == nil {
 			return chunk, nil
 		}
@@ -140,14 +157,14 @@ func (ns *NetStore) get(addr Address, timeout time.Duration) (chunk *Chunk, err
 		}
 	} else {
 		var created bool
-		chunk, created = ns.localStore.GetOrCreateRequest(addr)
+		chunk, created = ns.localStore.GetOrCreateRequest(ctx, addr)
 
 		if chunk.ReqC == nil {
 			return chunk, nil
 		}
 
 		if created {
-			err := ns.retrieve(chunk)
+			err := ns.retrieve(ctx, chunk)
 			if err != nil {
 				// mark chunk request as failed so that we can retry it later
 				chunk.SetErrored(ErrChunkUnavailable)
@@ -171,8 +188,8 @@ func (ns *NetStore) get(addr Address, timeout time.Duration) (chunk *Chunk, err
 }
 
 // Put is the entrypoint for local store requests coming from storeLoop
-func (ns *NetStore) Put(chunk *Chunk) {
+func (ns *NetStore) Put(ctx context.Context, chunk *Chunk) {
-	ns.localStore.Put(chunk)
+	ns.localStore.Put(ctx, chunk)
 }
 
 // Close chunk store

swarm/storage/netstore_test.go

@@ -17,6 +17,7 @@
 package storage
 
 import (
+	"context"
 	"encoding/hex"
 	"errors"
 	"io/ioutil"
@@ -46,7 +47,7 @@ func newDummyChunk(addr Address) *Chunk {
 	return chunk
 }
 
-func (m *mockRetrieve) retrieve(chunk *Chunk) error {
+func (m *mockRetrieve) retrieve(ctx context.Context, chunk *Chunk) error {
 	hkey := hex.EncodeToString(chunk.Addr)
 	m.requests[hkey] += 1
 
@@ -100,7 +101,7 @@ func TestNetstoreFailedRequest(t *testing.T) {
 	// }
 
 	// second call
-	_, err = netStore.Get(key)
+	_, err = netStore.Get(context.TODO(), key)
 	if got := r.requests[hex.EncodeToString(key)]; got != 2 {
 		t.Fatalf("expected to have called retrieve two times, but got: %v", got)
 	}
@@ -109,7 +110,7 @@ func TestNetstoreFailedRequest(t *testing.T) {
 	}
 
 	// third call
-	chunk, err := netStore.Get(key)
+	chunk, err := netStore.Get(context.TODO(), key)
 	if got := r.requests[hex.EncodeToString(key)]; got != 3 {
 		t.Fatalf("expected to have called retrieve three times, but got: %v", got)
 	}

swarm/storage/pyramid.go

@@ -287,7 +287,7 @@ func (pc *PyramidChunker) processor(id int64) {
 func (pc *PyramidChunker) processChunk(id int64, job *chunkJob) {
 	log.Debug("pyramid.chunker: processChunk()", "id", id)
 
-	ref, err := pc.putter.Put(job.chunk)
+	ref, err := pc.putter.Put(context.TODO(), job.chunk)
 	if err != nil {
 		pc.errC <- err
 	}
@@ -302,7 +302,7 @@ func (pc *PyramidChunker) processChunk(id int64, job *chunkJob) {
 func (pc *PyramidChunker) loadTree() error {
 	log.Debug("pyramid.chunker: loadTree()")
 	// Get the root chunk to get the total size
-	chunkData, err := pc.getter.Get(Reference(pc.key))
+	chunkData, err := pc.getter.Get(context.TODO(), Reference(pc.key))
 	if err != nil {
 		return errLoadingTreeRootChunk
 	}
@@ -355,7 +355,7 @@ func (pc *PyramidChunker) loadTree() error {
 			branchCount = int64(len(ent.chunk)-8) / pc.hashSize
 			for i := int64(0); i < branchCount; i++ {
 				key := ent.chunk[8+(i*pc.hashSize) : 8+((i+1)*pc.hashSize)]
-				newChunkData, err := pc.getter.Get(Reference(key))
+				newChunkData, err := pc.getter.Get(context.TODO(), Reference(key))
 				if err != nil {
 					return errLoadingTreeChunk
 				}
@@ -417,7 +417,7 @@ func (pc *PyramidChunker) prepareChunks(isAppend bool) {
 			lastKey := parent.chunk[8+lastBranch*pc.hashSize : 8+(lastBranch+1)*pc.hashSize]
 
 			var err error
-			unfinishedChunkData, err = pc.getter.Get(lastKey)
+			unfinishedChunkData, err = pc.getter.Get(context.TODO(), lastKey)
 			if err != nil {
 				pc.errC <- err
 			}

swarm/storage/types.go

@@ -250,7 +250,8 @@ func GenerateRandomChunks(dataSize int64, count int) (chunks []*Chunk) {
 
 // Size, Seek, Read, ReadAt
 type LazySectionReader interface {
-	Size(chan bool) (int64, error)
+	Context() context.Context
+	Size(context.Context, chan bool) (int64, error)
 	io.Seeker
 	io.Reader
 	io.ReaderAt
@@ -260,10 +261,14 @@ type LazyTestSectionReader struct {
 	*io.SectionReader
 }
 
-func (r *LazyTestSectionReader) Size(chan bool) (int64, error) {
+func (r *LazyTestSectionReader) Size(context.Context, chan bool) (int64, error) {
 	return r.SectionReader.Size(), nil
 }
 
+func (r *LazyTestSectionReader) Context() context.Context {
+	return context.TODO()
+}
+
 type StoreParams struct {
 	Hash                       SwarmHasher `toml:"-"`
 	DbCapacity                 uint64
@@ -298,7 +303,7 @@ type Reference []byte
 
 // Putter is responsible to store data and create a reference for it
 type Putter interface {
-	Put(ChunkData) (Reference, error)
+	Put(context.Context, ChunkData) (Reference, error)
 	// RefSize returns the length of the Reference created by this Putter
 	RefSize() int64
 	// Close is to indicate that no more chunk data will be Put on this Putter
@@ -309,7 +314,7 @@ type Putter interface {
 
 // Getter is an interface to retrieve a chunk's data by its reference
 type Getter interface {
-	Get(Reference) (ChunkData, error)
+	Get(context.Context, Reference) (ChunkData, error)
 }
 
 // NOTE: this returns invalid data if chunk is encrypted

swarm/swarm.go

@@ -21,6 +21,7 @@ import (
 	"context"
 	"crypto/ecdsa"
 	"fmt"
+	"io"
 	"math/big"
 	"net"
 	"path/filepath"
@@ -50,6 +51,7 @@ import (
 	"github.com/ethereum/go-ethereum/swarm/storage"
 	"github.com/ethereum/go-ethereum/swarm/storage/mock"
 	"github.com/ethereum/go-ethereum/swarm/storage/mru"
+	"github.com/ethereum/go-ethereum/swarm/tracing"
 )
 
 var (
@@ -76,6 +78,8 @@ type Swarm struct {
 	lstore      *storage.LocalStore // local store, needs to store for releasing resources after node stopped
 	sfs         *fuse.SwarmFS       // need this to cleanup all the active mounts on node exit
 	ps          *pss.Pss
+
+	tracerClose io.Closer
 }
 
 type SwarmAPI struct {
@@ -356,6 +360,8 @@ Start is called when the stack is started
 func (self *Swarm) Start(srv *p2p.Server) error {
 	startTime = time.Now()
 
+	self.tracerClose = tracing.Closer
+
 	// update uaddr to correct enode
 	newaddr := self.bzz.UpdateLocalAddr([]byte(srv.Self().String()))
 	log.Warn("Updated bzz local addr", "oaddr", fmt.Sprintf("%x", newaddr.OAddr), "uaddr", fmt.Sprintf("%s", newaddr.UAddr))
@@ -424,6 +430,13 @@ func (self *Swarm) updateGauges() {
 // implements the node.Service interface
 // stops all component services.
 func (self *Swarm) Stop() error {
+	if self.tracerClose != nil {
+		err := self.tracerClose.Close()
+		if err != nil {
+			return err
+		}
+	}
+
 	if self.ps != nil {
 		self.ps.Stop()
 	}

swarm/tracing/tracing.go

@@ -0,0 +1,103 @@
+package tracing
+
+import (
+	"io"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/log"
+	jaeger "github.com/uber/jaeger-client-go"
+	jaegercfg "github.com/uber/jaeger-client-go/config"
+	jaegerlog "github.com/uber/jaeger-client-go/log"
+	cli "gopkg.in/urfave/cli.v1"
+)
+
+var Enabled bool = false
+
+// TracingEnabledFlag is the CLI flag name to use to enable trace collections.
+const TracingEnabledFlag = "tracing"
+
+var (
+	Closer io.Closer
+)
+
+var (
+	TracingFlag = cli.BoolFlag{
+		Name:  TracingEnabledFlag,
+		Usage: "Enable tracing",
+	}
+	TracingEndpointFlag = cli.StringFlag{
+		Name:  "tracing.endpoint",
+		Usage: "Tracing endpoint",
+		Value: "0.0.0.0:6831",
+	}
+	TracingSvcFlag = cli.StringFlag{
+		Name:  "tracing.svc",
+		Usage: "Tracing service name",
+		Value: "swarm",
+	}
+)
+
+// Flags holds all command-line flags required for tracing collection.
+var Flags = []cli.Flag{
+	TracingFlag,
+	TracingEndpointFlag,
+	TracingSvcFlag,
+}
+
+// Init enables or disables the open tracing system.
+func init() {
+	for _, arg := range os.Args {
+		if flag := strings.TrimLeft(arg, "-"); flag == TracingEnabledFlag {
+			Enabled = true
+		}
+	}
+}
+
+func Setup(ctx *cli.Context) {
+	if Enabled {
+		log.Info("Enabling opentracing")
+		var (
+			endpoint = ctx.GlobalString(TracingEndpointFlag.Name)
+			svc      = ctx.GlobalString(TracingSvcFlag.Name)
+		)
+
+		Closer = initTracer(endpoint, svc)
+	}
+}
+
+func initTracer(endpoint, svc string) (closer io.Closer) {
+	// Sample configuration for testing. Use constant sampling to sample every trace
+	// and enable LogSpan to log every span via configured Logger.
+	cfg := jaegercfg.Configuration{
+		Sampler: &jaegercfg.SamplerConfig{
+			Type:  jaeger.SamplerTypeConst,
+			Param: 1,
+		},
+		Reporter: &jaegercfg.ReporterConfig{
+			LogSpans:            true,
+			BufferFlushInterval: 1 * time.Second,
+			LocalAgentHostPort:  endpoint,
+		},
+	}
+
+	// Example logger and metrics factory. Use github.com/uber/jaeger-client-go/log
+	// and github.com/uber/jaeger-lib/metrics respectively to bind to real logging and metrics
+	// frameworks.
+	jLogger := jaegerlog.StdLogger
+	//jMetricsFactory := metrics.NullFactory
+
+	// Initialize tracer with a logger and a metrics factory
+	closer, err := cfg.InitGlobalTracer(
+		svc,
+		jaegercfg.Logger(jLogger),
+		//jaegercfg.Metrics(jMetricsFactory),
+		//jaegercfg.Observer(rpcmetrics.NewObserver(jMetricsFactory, rpcmetrics.DefaultNameNormalizer)),
+	)
+	if err != nil {
+		log.Error("Could not initialize Jaeger tracer", "err", err)
+	}
+
+	return closer
+}

vendor/github.com/codahale/hdrhistogram/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Coda Hale
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

vendor/github.com/codahale/hdrhistogram/README.md

@@ -0,0 +1,15 @@
+hdrhistogram
+============
+
+[![Build Status](https://travis-ci.org/codahale/hdrhistogram.png?branch=master)](https://travis-ci.org/codahale/hdrhistogram)
+
+A pure Go implementation of the [HDR Histogram](https://github.com/HdrHistogram/HdrHistogram).
+
+> A Histogram that supports recording and analyzing sampled data value counts
+> across a configurable integer value range with configurable value precision
+> within the range. Value precision is expressed as the number of significant
+> digits in the value recording, and provides control over value quantization
+> behavior across the value range and the subsequent value resolution at any
+> given level.
+
+For documentation, check [godoc](http://godoc.org/github.com/codahale/hdrhistogram).

vendor/github.com/codahale/hdrhistogram/hdr.go

@@ -0,0 +1,564 @@
+// Package hdrhistogram provides an implementation of Gil Tene's HDR Histogram
+// data structure. The HDR Histogram allows for fast and accurate analysis of
+// the extreme ranges of data with non-normal distributions, like latency.
+package hdrhistogram
+
+import (
+	"fmt"
+	"math"
+)
+
+// A Bracket is a part of a cumulative distribution.
+type Bracket struct {
+	Quantile       float64
+	Count, ValueAt int64
+}
+
+// A Snapshot is an exported view of a Histogram, useful for serializing them.
+// A Histogram can be constructed from it by passing it to Import.
+type Snapshot struct {
+	LowestTrackableValue  int64
+	HighestTrackableValue int64
+	SignificantFigures    int64
+	Counts                []int64
+}
+
+// A Histogram is a lossy data structure used to record the distribution of
+// non-normally distributed data (like latency) with a high degree of accuracy
+// and a bounded degree of precision.
+type Histogram struct {
+	lowestTrackableValue        int64
+	highestTrackableValue       int64
+	unitMagnitude               int64
+	significantFigures          int64
+	subBucketHalfCountMagnitude int32
+	subBucketHalfCount          int32
+	subBucketMask               int64
+	subBucketCount              int32
+	bucketCount                 int32
+	countsLen                   int32
+	totalCount                  int64
+	counts                      []int64
+}
+
+// New returns a new Histogram instance capable of tracking values in the given
+// range and with the given amount of precision.
+func New(minValue, maxValue int64, sigfigs int) *Histogram {
+	if sigfigs < 1 || 5 < sigfigs {
+		panic(fmt.Errorf("sigfigs must be [1,5] (was %d)", sigfigs))
+	}
+
+	largestValueWithSingleUnitResolution := 2 * math.Pow10(sigfigs)
+	subBucketCountMagnitude := int32(math.Ceil(math.Log2(float64(largestValueWithSingleUnitResolution))))
+
+	subBucketHalfCountMagnitude := subBucketCountMagnitude
+	if subBucketHalfCountMagnitude < 1 {
+		subBucketHalfCountMagnitude = 1
+	}
+	subBucketHalfCountMagnitude--
+
+	unitMagnitude := int32(math.Floor(math.Log2(float64(minValue))))
+	if unitMagnitude < 0 {
+		unitMagnitude = 0
+	}
+
+	subBucketCount := int32(math.Pow(2, float64(subBucketHalfCountMagnitude)+1))
+
+	subBucketHalfCount := subBucketCount / 2
+	subBucketMask := int64(subBucketCount-1) << uint(unitMagnitude)
+
+	// determine exponent range needed to support the trackable value with no
+	// overflow:
+	smallestUntrackableValue := int64(subBucketCount) << uint(unitMagnitude)
+	bucketsNeeded := int32(1)
+	for smallestUntrackableValue < maxValue {
+		smallestUntrackableValue <<= 1
+		bucketsNeeded++
+	}
+
+	bucketCount := bucketsNeeded
+	countsLen := (bucketCount + 1) * (subBucketCount / 2)
+
+	return &Histogram{
+		lowestTrackableValue:        minValue,
+		highestTrackableValue:       maxValue,
+		unitMagnitude:               int64(unitMagnitude),
+		significantFigures:          int64(sigfigs),
+		subBucketHalfCountMagnitude: subBucketHalfCountMagnitude,
+		subBucketHalfCount:          subBucketHalfCount,
+		subBucketMask:               subBucketMask,
+		subBucketCount:              subBucketCount,
+		bucketCount:                 bucketCount,
+		countsLen:                   countsLen,
+		totalCount:                  0,
+		counts:                      make([]int64, countsLen),
+	}
+}
+
+// ByteSize returns an estimate of the amount of memory allocated to the
+// histogram in bytes.
+//
+// N.B.: This does not take into account the overhead for slices, which are
+// small, constant, and specific to the compiler version.
+func (h *Histogram) ByteSize() int {
+	return 6*8 + 5*4 + len(h.counts)*8
+}
+
+// Merge merges the data stored in the given histogram with the receiver,
+// returning the number of recorded values which had to be dropped.
+func (h *Histogram) Merge(from *Histogram) (dropped int64) {
+	i := from.rIterator()
+	for i.next() {
+		v := i.valueFromIdx
+		c := i.countAtIdx
+
+		if h.RecordValues(v, c) != nil {
+			dropped += c
+		}
+	}
+
+	return
+}
+
+// TotalCount returns total number of values recorded.
+func (h *Histogram) TotalCount() int64 {
+	return h.totalCount
+}
+
+// Max returns the approximate maximum recorded value.
+func (h *Histogram) Max() int64 {
+	var max int64
+	i := h.iterator()
+	for i.next() {
+		if i.countAtIdx != 0 {
+			max = i.highestEquivalentValue
+		}
+	}
+	return h.highestEquivalentValue(max)
+}
+
+// Min returns the approximate minimum recorded value.
+func (h *Histogram) Min() int64 {
+	var min int64
+	i := h.iterator()
+	for i.next() {
+		if i.countAtIdx != 0 && min == 0 {
+			min = i.highestEquivalentValue
+			break
+		}
+	}
+	return h.lowestEquivalentValue(min)
+}
+
+// Mean returns the approximate arithmetic mean of the recorded values.
+func (h *Histogram) Mean() float64 {
+	if h.totalCount == 0 {
+		return 0
+	}
+	var total int64
+	i := h.iterator()
+	for i.next() {
+		if i.countAtIdx != 0 {
+			total += i.countAtIdx * h.medianEquivalentValue(i.valueFromIdx)
+		}
+	}
+	return float64(total) / float64(h.totalCount)
+}
+
+// StdDev returns the approximate standard deviation of the recorded values.
+func (h *Histogram) StdDev() float64 {
+	if h.totalCount == 0 {
+		return 0
+	}
+
+	mean := h.Mean()
+	geometricDevTotal := 0.0
+
+	i := h.iterator()
+	for i.next() {
+		if i.countAtIdx != 0 {
+			dev := float64(h.medianEquivalentValue(i.valueFromIdx)) - mean
+			geometricDevTotal += (dev * dev) * float64(i.countAtIdx)
+		}
+	}
+
+	return math.Sqrt(geometricDevTotal / float64(h.totalCount))
+}
+
+// Reset deletes all recorded values and restores the histogram to its original
+// state.
+func (h *Histogram) Reset() {
+	h.totalCount = 0
+	for i := range h.counts {
+		h.counts[i] = 0
+	}
+}
+
+// RecordValue records the given value, returning an error if the value is out
+// of range.
+func (h *Histogram) RecordValue(v int64) error {
+	return h.RecordValues(v, 1)
+}
+
+// RecordCorrectedValue records the given value, correcting for stalls in the
+// recording process. This only works for processes which are recording values
+// at an expected interval (e.g., doing jitter analysis). Processes which are
+// recording ad-hoc values (e.g., latency for incoming requests) can't take
+// advantage of this.
+func (h *Histogram) RecordCorrectedValue(v, expectedInterval int64) error {
+	if err := h.RecordValue(v); err != nil {
+		return err
+	}
+
+	if expectedInterval <= 0 || v <= expectedInterval {
+		return nil
+	}
+
+	missingValue := v - expectedInterval
+	for missingValue >= expectedInterval {
+		if err := h.RecordValue(missingValue); err != nil {
+			return err
+		}
+		missingValue -= expectedInterval
+	}
+
+	return nil
+}
+
+// RecordValues records n occurrences of the given value, returning an error if
+// the value is out of range.
+func (h *Histogram) RecordValues(v, n int64) error {
+	idx := h.countsIndexFor(v)
+	if idx < 0 || int(h.countsLen) <= idx {
+		return fmt.Errorf("value %d is too large to be recorded", v)
+	}
+	h.counts[idx] += n
+	h.totalCount += n
+
+	return nil
+}
+
+// ValueAtQuantile returns the recorded value at the given quantile (0..100).
+func (h *Histogram) ValueAtQuantile(q float64) int64 {
+	if q > 100 {
+		q = 100
+	}
+
+	total := int64(0)
+	countAtPercentile := int64(((q / 100) * float64(h.totalCount)) + 0.5)
+
+	i := h.iterator()
+	for i.next() {
+		total += i.countAtIdx
+		if total >= countAtPercentile {
+			return h.highestEquivalentValue(i.valueFromIdx)
+		}
+	}
+
+	return 0
+}
+
+// CumulativeDistribution returns an ordered list of brackets of the
+// distribution of recorded values.
+func (h *Histogram) CumulativeDistribution() []Bracket {
+	var result []Bracket
+
+	i := h.pIterator(1)
+	for i.next() {
+		result = append(result, Bracket{
+			Quantile: i.percentile,
+			Count:    i.countToIdx,
+			ValueAt:  i.highestEquivalentValue,
+		})
+	}
+
+	return result
+}
+
+// SignificantFigures returns the significant figures used to create the
+// histogram
+func (h *Histogram) SignificantFigures() int64 {
+	return h.significantFigures
+}
+
+// LowestTrackableValue returns the lower bound on values that will be added
+// to the histogram
+func (h *Histogram) LowestTrackableValue() int64 {
+	return h.lowestTrackableValue
+}
+
+// HighestTrackableValue returns the upper bound on values that will be added
+// to the histogram
+func (h *Histogram) HighestTrackableValue() int64 {
+	return h.highestTrackableValue
+}
+
+// Histogram bar for plotting
+type Bar struct {
+	From, To, Count int64
+}
+
+// Pretty print as csv for easy plotting
+func (b Bar) String() string {
+	return fmt.Sprintf("%v, %v, %v\n", b.From, b.To, b.Count)
+}
+
+// Distribution returns an ordered list of bars of the
+// distribution of recorded values, counts can be normalized to a probability
+func (h *Histogram) Distribution() (result []Bar) {
+	i := h.iterator()
+	for i.next() {
+		result = append(result, Bar{
+			Count: i.countAtIdx,
+			From:  h.lowestEquivalentValue(i.valueFromIdx),
+			To:    i.highestEquivalentValue,
+		})
+	}
+
+	return result
+}
+
+// Equals returns true if the two Histograms are equivalent, false if not.
+func (h *Histogram) Equals(other *Histogram) bool {
+	switch {
+	case
+		h.lowestTrackableValue != other.lowestTrackableValue,
+		h.highestTrackableValue != other.highestTrackableValue,
+		h.unitMagnitude != other.unitMagnitude,
+		h.significantFigures != other.significantFigures,
+		h.subBucketHalfCountMagnitude != other.subBucketHalfCountMagnitude,
+		h.subBucketHalfCount != other.subBucketHalfCount,
+		h.subBucketMask != other.subBucketMask,
+		h.subBucketCount != other.subBucketCount,
+		h.bucketCount != other.bucketCount,
+		h.countsLen != other.countsLen,
+		h.totalCount != other.totalCount:
+		return false
+	default:
+		for i, c := range h.counts {
+			if c != other.counts[i] {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Export returns a snapshot view of the Histogram. This can be later passed to
+// Import to construct a new Histogram with the same state.
+func (h *Histogram) Export() *Snapshot {
+	return &Snapshot{
+		LowestTrackableValue:  h.lowestTrackableValue,
+		HighestTrackableValue: h.highestTrackableValue,
+		SignificantFigures:    h.significantFigures,
+		Counts:                append([]int64(nil), h.counts...), // copy
+	}
+}
+
+// Import returns a new Histogram populated from the Snapshot data (which the
+// caller must stop accessing).
+func Import(s *Snapshot) *Histogram {
+	h := New(s.LowestTrackableValue, s.HighestTrackableValue, int(s.SignificantFigures))
+	h.counts = s.Counts
+	totalCount := int64(0)
+	for i := int32(0); i < h.countsLen; i++ {
+		countAtIndex := h.counts[i]
+		if countAtIndex > 0 {
+			totalCount += countAtIndex
+		}
+	}
+	h.totalCount = totalCount
+	return h
+}
+
+func (h *Histogram) iterator() *iterator {
+	return &iterator{
+		h:            h,
+		subBucketIdx: -1,
+	}
+}
+
+func (h *Histogram) rIterator() *rIterator {
+	return &rIterator{
+		iterator: iterator{
+			h:            h,
+			subBucketIdx: -1,
+		},
+	}
+}
+
+func (h *Histogram) pIterator(ticksPerHalfDistance int32) *pIterator {
+	return &pIterator{
+		iterator: iterator{
+			h:            h,
+			subBucketIdx: -1,
+		},
+		ticksPerHalfDistance: ticksPerHalfDistance,
+	}
+}
+
+func (h *Histogram) sizeOfEquivalentValueRange(v int64) int64 {
+	bucketIdx := h.getBucketIndex(v)
+	subBucketIdx := h.getSubBucketIdx(v, bucketIdx)
+	adjustedBucket := bucketIdx
+	if subBucketIdx >= h.subBucketCount {
+		adjustedBucket++
+	}
+	return int64(1) << uint(h.unitMagnitude+int64(adjustedBucket))
+}
+
+func (h *Histogram) valueFromIndex(bucketIdx, subBucketIdx int32) int64 {
+	return int64(subBucketIdx) << uint(int64(bucketIdx)+h.unitMagnitude)
+}
+
+func (h *Histogram) lowestEquivalentValue(v int64) int64 {
+	bucketIdx := h.getBucketIndex(v)
+	subBucketIdx := h.getSubBucketIdx(v, bucketIdx)
+	return h.valueFromIndex(bucketIdx, subBucketIdx)
+}
+
+func (h *Histogram) nextNonEquivalentValue(v int64) int64 {
+	return h.lowestEquivalentValue(v) + h.sizeOfEquivalentValueRange(v)
+}
+
+func (h *Histogram) highestEquivalentValue(v int64) int64 {
+	return h.nextNonEquivalentValue(v) - 1
+}
+
+func (h *Histogram) medianEquivalentValue(v int64) int64 {
+	return h.lowestEquivalentValue(v) + (h.sizeOfEquivalentValueRange(v) >> 1)
+}
+
+func (h *Histogram) getCountAtIndex(bucketIdx, subBucketIdx int32) int64 {
+	return h.counts[h.countsIndex(bucketIdx, subBucketIdx)]
+}
+
+func (h *Histogram) countsIndex(bucketIdx, subBucketIdx int32) int32 {
+	bucketBaseIdx := (bucketIdx + 1) << uint(h.subBucketHalfCountMagnitude)
+	offsetInBucket := subBucketIdx - h.subBucketHalfCount
+	return bucketBaseIdx + offsetInBucket
+}
+
+func (h *Histogram) getBucketIndex(v int64) int32 {
+	pow2Ceiling := bitLen(v | h.subBucketMask)
+	return int32(pow2Ceiling - int64(h.unitMagnitude) -
+		int64(h.subBucketHalfCountMagnitude+1))
+}
+
+func (h *Histogram) getSubBucketIdx(v int64, idx int32) int32 {
+	return int32(v >> uint(int64(idx)+int64(h.unitMagnitude)))
+}
+
+func (h *Histogram) countsIndexFor(v int64) int {
+	bucketIdx := h.getBucketIndex(v)
+	subBucketIdx := h.getSubBucketIdx(v, bucketIdx)
+	return int(h.countsIndex(bucketIdx, subBucketIdx))
+}
+
+type iterator struct {
+	h                                    *Histogram
+	bucketIdx, subBucketIdx              int32
+	countAtIdx, countToIdx, valueFromIdx int64
+	highestEquivalentValue               int64
+}
+
+func (i *iterator) next() bool {
+	if i.countToIdx >= i.h.totalCount {
+		return false
+	}
+
+	// increment bucket
+	i.subBucketIdx++
+	if i.subBucketIdx >= i.h.subBucketCount {
+		i.subBucketIdx = i.h.subBucketHalfCount
+		i.bucketIdx++
+	}
+
+	if i.bucketIdx >= i.h.bucketCount {
+		return false
+	}
+
+	i.countAtIdx = i.h.getCountAtIndex(i.bucketIdx, i.subBucketIdx)
+	i.countToIdx += i.countAtIdx
+	i.valueFromIdx = i.h.valueFromIndex(i.bucketIdx, i.subBucketIdx)
+	i.highestEquivalentValue = i.h.highestEquivalentValue(i.valueFromIdx)
+
+	return true
+}
+
+type rIterator struct {
+	iterator
+	countAddedThisStep int64
+}
+
+func (r *rIterator) next() bool {
+	for r.iterator.next() {
+		if r.countAtIdx != 0 {
+			r.countAddedThisStep = r.countAtIdx
+			return true
+		}
+	}
+	return false
+}
+
+type pIterator struct {
+	iterator
+	seenLastValue          bool
+	ticksPerHalfDistance   int32
+	percentileToIteratorTo float64
+	percentile             float64
+}
+
+func (p *pIterator) next() bool {
+	if !(p.countToIdx < p.h.totalCount) {
+		if p.seenLastValue {
+			return false
+		}
+
+		p.seenLastValue = true
+		p.percentile = 100
+
+		return true
+	}
+
+	if p.subBucketIdx == -1 && !p.iterator.next() {
+		return false
+	}
+
+	var done = false
+	for !done {
+		currentPercentile := (100.0 * float64(p.countToIdx)) / float64(p.h.totalCount)
+		if p.countAtIdx != 0 && p.percentileToIteratorTo <= currentPercentile {
+			p.percentile = p.percentileToIteratorTo
+			halfDistance := math.Trunc(math.Pow(2, math.Trunc(math.Log2(100.0/(100.0-p.percentileToIteratorTo)))+1))
+			percentileReportingTicks := float64(p.ticksPerHalfDistance) * halfDistance
+			p.percentileToIteratorTo += 100.0 / percentileReportingTicks
+			return true
+		}
+		done = !p.iterator.next()
+	}
+
+	return true
+}
+
+func bitLen(x int64) (n int64) {
+	for ; x >= 0x8000; x >>= 16 {
+		n += 16
+	}
+	if x >= 0x80 {
+		x >>= 8
+		n += 8
+	}
+	if x >= 0x8 {
+		x >>= 4
+		n += 4
+	}
+	if x >= 0x2 {
+		x >>= 2
+		n += 2
+	}
+	if x >= 0x1 {
+		n++
+	}
+	return
+}

vendor/github.com/codahale/hdrhistogram/window.go

@@ -0,0 +1,45 @@
+package hdrhistogram
+
+// A WindowedHistogram combines histograms to provide windowed statistics.
+type WindowedHistogram struct {
+	idx int
+	h   []Histogram
+	m   *Histogram
+
+	Current *Histogram
+}
+
+// NewWindowed creates a new WindowedHistogram with N underlying histograms with
+// the given parameters.
+func NewWindowed(n int, minValue, maxValue int64, sigfigs int) *WindowedHistogram {
+	w := WindowedHistogram{
+		idx: -1,
+		h:   make([]Histogram, n),
+		m:   New(minValue, maxValue, sigfigs),
+	}
+
+	for i := range w.h {
+		w.h[i] = *New(minValue, maxValue, sigfigs)
+	}
+	w.Rotate()
+
+	return &w
+}
+
+// Merge returns a histogram which includes the recorded values from all the
+// sections of the window.
+func (w *WindowedHistogram) Merge() *Histogram {
+	w.m.Reset()
+	for _, h := range w.h {
+		w.m.Merge(&h)
+	}
+	return w.m
+}
+
+// Rotate resets the oldest histogram and rotates it to be used as the current
+// histogram.
+func (w *WindowedHistogram) Rotate() {
+	w.idx++
+	w.Current = &w.h[w.idx%len(w.h)]
+	w.Current.Reset()
+}

vendor/github.com/opentracing/opentracing-go/CHANGELOG.md

@@ -0,0 +1,14 @@
+Changes by Version
+==================
+
+1.1.0 (unreleased)
+-------------------
+
+- Deprecate InitGlobalTracer() in favor of SetGlobalTracer()
+
+
+1.0.0 (2016-09-26)
+-------------------
+
+- This release implements OpenTracing Specification 1.0 (http://opentracing.io/spec)
+

vendor/github.com/opentracing/opentracing-go/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright 2016 The OpenTracing Authors
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/opentracing/opentracing-go/Makefile

@@ -0,0 +1,32 @@
+PACKAGES := . ./mocktracer/... ./ext/...
+
+.DEFAULT_GOAL := test-and-lint
+
+.PHONE: test-and-lint
+
+test-and-lint: test lint
+
+.PHONY: test
+test:
+	go test -v -cover -race ./...
+
+cover:
+	@rm -rf cover-all.out
+	$(foreach pkg, $(PACKAGES), $(MAKE) cover-pkg PKG=$(pkg) || true;)
+	@grep mode: cover.out > coverage.out
+	@cat cover-all.out >> coverage.out
+	go tool cover -html=coverage.out -o cover.html
+	@rm -rf cover.out cover-all.out coverage.out
+
+cover-pkg:
+	go test -coverprofile cover.out $(PKG)
+	@grep -v mode: cover.out >> cover-all.out
+
+.PHONY: lint
+lint:
+	go fmt ./...
+	golint ./...
+	@# Run again with magic to exit non-zero if golint outputs anything.
+	@! (golint ./... | read dummy)
+	go vet ./...
+

vendor/github.com/opentracing/opentracing-go/README.md

@@ -0,0 +1,171 @@
+[![Gitter chat](http://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/opentracing/public) [![Build Status](https://travis-ci.org/opentracing/opentracing-go.svg?branch=master)](https://travis-ci.org/opentracing/opentracing-go) [![GoDoc](https://godoc.org/github.com/opentracing/opentracing-go?status.svg)](http://godoc.org/github.com/opentracing/opentracing-go)
+[![Sourcegraph Badge](https://sourcegraph.com/github.com/opentracing/opentracing-go/-/badge.svg)](https://sourcegraph.com/github.com/opentracing/opentracing-go?badge)
+
+# OpenTracing API for Go
+
+This package is a Go platform API for OpenTracing.
+
+## Required Reading
+
+In order to understand the Go platform API, one must first be familiar with the
+[OpenTracing project](http://opentracing.io) and
+[terminology](http://opentracing.io/documentation/pages/spec.html) more specifically.
+
+## API overview for those adding instrumentation
+
+Everyday consumers of this `opentracing` package really only need to worry
+about a couple of key abstractions: the `StartSpan` function, the `Span`
+interface, and binding a `Tracer` at `main()`-time. Here are code snippets
+demonstrating some important use cases.
+
+#### Singleton initialization
+
+The simplest starting point is `./default_tracer.go`. As early as possible, call
+
+```go
+    import "github.com/opentracing/opentracing-go"
+    import ".../some_tracing_impl"
+
+    func main() {
+        opentracing.SetGlobalTracer(
+            // tracing impl specific:
+            some_tracing_impl.New(...),
+        )
+        ...
+    }
+```
+
+#### Non-Singleton initialization
+
+If you prefer direct control to singletons, manage ownership of the
+`opentracing.Tracer` implementation explicitly.
+
+#### Creating a Span given an existing Go `context.Context`
+
+If you use `context.Context` in your application, OpenTracing's Go library will
+happily rely on it for `Span` propagation. To start a new (blocking child)
+`Span`, you can use `StartSpanFromContext`.
+
+```go
+    func xyz(ctx context.Context, ...) {
+        ...
+        span, ctx := opentracing.StartSpanFromContext(ctx, "operation_name")
+        defer span.Finish()
+        span.LogFields(
+            log.String("event", "soft error"),
+            log.String("type", "cache timeout"),
+            log.Int("waited.millis", 1500))
+        ...
+    }
+```
+
+#### Starting an empty trace by creating a "root span"
+
+It's always possible to create a "root" `Span` with no parent or other causal
+reference.
+
+```go
+    func xyz() {
+        ...
+        sp := opentracing.StartSpan("operation_name")
+        defer sp.Finish()
+        ...
+    }
+```
+
+#### Creating a (child) Span given an existing (parent) Span
+
+```go
+    func xyz(parentSpan opentracing.Span, ...) {
+        ...
+        sp := opentracing.StartSpan(
+            "operation_name",
+            opentracing.ChildOf(parentSpan.Context()))
+        defer sp.Finish()
+        ...
+    }
+```
+
+#### Serializing to the wire
+
+```go
+    func makeSomeRequest(ctx context.Context) ... {
+        if span := opentracing.SpanFromContext(ctx); span != nil {
+            httpClient := &http.Client{}
+            httpReq, _ := http.NewRequest("GET", "http://myservice/", nil)
+
+            // Transmit the span's TraceContext as HTTP headers on our
+            // outbound request.
+            opentracing.GlobalTracer().Inject(
+                span.Context(),
+                opentracing.HTTPHeaders,
+                opentracing.HTTPHeadersCarrier(httpReq.Header))
+
+            resp, err := httpClient.Do(httpReq)
+            ...
+        }
+        ...
+    }
+```
+
+#### Deserializing from the wire
+
+```go
+    http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+        var serverSpan opentracing.Span
+        appSpecificOperationName := ...
+        wireContext, err := opentracing.GlobalTracer().Extract(
+            opentracing.HTTPHeaders,
+            opentracing.HTTPHeadersCarrier(req.Header))
+        if err != nil {
+            // Optionally record something about err here
+        }
+
+        // Create the span referring to the RPC client if available.
+        // If wireContext == nil, a root span will be created.
+        serverSpan = opentracing.StartSpan(
+            appSpecificOperationName,
+            ext.RPCServerOption(wireContext))
+
+        defer serverSpan.Finish()
+
+        ctx := opentracing.ContextWithSpan(context.Background(), serverSpan)
+        ...
+    }
+```
+
+#### Conditionally capture a field using `log.Noop`
+
+In some situations, you may want to dynamically decide whether or not
+to log a field.  For example, you may want to capture additional data,
+such as a customer ID, in non-production environments:
+
+```go
+    func Customer(order *Order) log.Field {
+        if os.Getenv("ENVIRONMENT") == "dev" {
+            return log.String("customer", order.Customer.ID)
+        }
+        return log.Noop()
+    }
+```
+
+#### Goroutine-safety
+
+The entire public API is goroutine-safe and does not require external
+synchronization.
+
+## API pointers for those implementing a tracing system
+
+Tracing system implementors may be able to reuse or copy-paste-modify the `basictracer` package, found [here](https://github.com/opentracing/basictracer-go). In particular, see `basictracer.New(...)`.
+
+## API compatibility
+
+For the time being, "mild" backwards-incompatible changes may be made without changing the major version number. As OpenTracing and `opentracing-go` mature, backwards compatibility will become more of a priority.
+
+## Tracer test suite
+
+A test suite is available in the [harness](https://godoc.org/github.com/opentracing/opentracing-go/harness) package that can assist Tracer implementors to assert that their Tracer is working correctly.
+
+## Licensing
+
+[Apache 2.0 License](./LICENSE).

vendor/github.com/opentracing/opentracing-go/ext/tags.go

@@ -0,0 +1,210 @@
+package ext
+
+import opentracing "github.com/opentracing/opentracing-go"
+
+// These constants define common tag names recommended for better portability across
+// tracing systems and languages/platforms.
+//
+// The tag names are defined as typed strings, so that in addition to the usual use
+//
+//     span.setTag(TagName, value)
+//
+// they also support value type validation via this additional syntax:
+//
+//    TagName.Set(span, value)
+//
+var (
+	//////////////////////////////////////////////////////////////////////
+	// SpanKind (client/server or producer/consumer)
+	//////////////////////////////////////////////////////////////////////
+
+	// SpanKind hints at relationship between spans, e.g. client/server
+	SpanKind = spanKindTagName("span.kind")
+
+	// SpanKindRPCClient marks a span representing the client-side of an RPC
+	// or other remote call
+	SpanKindRPCClientEnum = SpanKindEnum("client")
+	SpanKindRPCClient     = opentracing.Tag{Key: string(SpanKind), Value: SpanKindRPCClientEnum}
+
+	// SpanKindRPCServer marks a span representing the server-side of an RPC
+	// or other remote call
+	SpanKindRPCServerEnum = SpanKindEnum("server")
+	SpanKindRPCServer     = opentracing.Tag{Key: string(SpanKind), Value: SpanKindRPCServerEnum}
+
+	// SpanKindProducer marks a span representing the producer-side of a
+	// message bus
+	SpanKindProducerEnum = SpanKindEnum("producer")
+	SpanKindProducer     = opentracing.Tag{Key: string(SpanKind), Value: SpanKindProducerEnum}
+
+	// SpanKindConsumer marks a span representing the consumer-side of a
+	// message bus
+	SpanKindConsumerEnum = SpanKindEnum("consumer")
+	SpanKindConsumer     = opentracing.Tag{Key: string(SpanKind), Value: SpanKindConsumerEnum}
+
+	//////////////////////////////////////////////////////////////////////
+	// Component name
+	//////////////////////////////////////////////////////////////////////
+
+	// Component is a low-cardinality identifier of the module, library,
+	// or package that is generating a span.
+	Component = stringTagName("component")
+
+	//////////////////////////////////////////////////////////////////////
+	// Sampling hint
+	//////////////////////////////////////////////////////////////////////
+
+	// SamplingPriority determines the priority of sampling this Span.
+	SamplingPriority = uint16TagName("sampling.priority")
+
+	//////////////////////////////////////////////////////////////////////
+	// Peer tags. These tags can be emitted by either client-side of
+	// server-side to describe the other side/service in a peer-to-peer
+	// communications, like an RPC call.
+	//////////////////////////////////////////////////////////////////////
+
+	// PeerService records the service name of the peer.
+	PeerService = stringTagName("peer.service")
+
+	// PeerAddress records the address name of the peer. This may be a "ip:port",
+	// a bare "hostname", a FQDN or even a database DSN substring
+	// like "mysql://username@127.0.0.1:3306/dbname"
+	PeerAddress = stringTagName("peer.address")
+
+	// PeerHostname records the host name of the peer
+	PeerHostname = stringTagName("peer.hostname")
+
+	// PeerHostIPv4 records IP v4 host address of the peer
+	PeerHostIPv4 = ipv4Tag("peer.ipv4")
+
+	// PeerHostIPv6 records IP v6 host address of the peer
+	PeerHostIPv6 = stringTagName("peer.ipv6")
+
+	// PeerPort records port number of the peer
+	PeerPort = uint16TagName("peer.port")
+
+	//////////////////////////////////////////////////////////////////////
+	// HTTP Tags
+	//////////////////////////////////////////////////////////////////////
+
+	// HTTPUrl should be the URL of the request being handled in this segment
+	// of the trace, in standard URI format. The protocol is optional.
+	HTTPUrl = stringTagName("http.url")
+
+	// HTTPMethod is the HTTP method of the request, and is case-insensitive.
+	HTTPMethod = stringTagName("http.method")
+
+	// HTTPStatusCode is the numeric HTTP status code (200, 404, etc) of the
+	// HTTP response.
+	HTTPStatusCode = uint16TagName("http.status_code")
+
+	//////////////////////////////////////////////////////////////////////
+	// DB Tags
+	//////////////////////////////////////////////////////////////////////
+
+	// DBInstance is database instance name.
+	DBInstance = stringTagName("db.instance")
+
+	// DBStatement is a database statement for the given database type.
+	// It can be a query or a prepared statement (i.e., before substitution).
+	DBStatement = stringTagName("db.statement")
+
+	// DBType is a database type. For any SQL database, "sql".
+	// For others, the lower-case database category, e.g. "redis"
+	DBType = stringTagName("db.type")
+
+	// DBUser is a username for accessing database.
+	DBUser = stringTagName("db.user")
+
+	//////////////////////////////////////////////////////////////////////
+	// Message Bus Tag
+	//////////////////////////////////////////////////////////////////////
+
+	// MessageBusDestination is an address at which messages can be exchanged
+	MessageBusDestination = stringTagName("message_bus.destination")
+
+	//////////////////////////////////////////////////////////////////////
+	// Error Tag
+	//////////////////////////////////////////////////////////////////////
+
+	// Error indicates that operation represented by the span resulted in an error.
+	Error = boolTagName("error")
+)
+
+// ---
+
+// SpanKindEnum represents common span types
+type SpanKindEnum string
+
+type spanKindTagName string
+
+// Set adds a string tag to the `span`
+func (tag spanKindTagName) Set(span opentracing.Span, value SpanKindEnum) {
+	span.SetTag(string(tag), value)
+}
+
+type rpcServerOption struct {
+	clientContext opentracing.SpanContext
+}
+
+func (r rpcServerOption) Apply(o *opentracing.StartSpanOptions) {
+	if r.clientContext != nil {
+		opentracing.ChildOf(r.clientContext).Apply(o)
+	}
+	SpanKindRPCServer.Apply(o)
+}
+
+// RPCServerOption returns a StartSpanOption appropriate for an RPC server span
+// with `client` representing the metadata for the remote peer Span if available.
+// In case client == nil, due to the client not being instrumented, this RPC
+// server span will be a root span.
+func RPCServerOption(client opentracing.SpanContext) opentracing.StartSpanOption {
+	return rpcServerOption{client}
+}
+
+// ---
+
+type stringTagName string
+
+// Set adds a string tag to the `span`
+func (tag stringTagName) Set(span opentracing.Span, value string) {
+	span.SetTag(string(tag), value)
+}
+
+// ---
+
+type uint32TagName string
+
+// Set adds a uint32 tag to the `span`
+func (tag uint32TagName) Set(span opentracing.Span, value uint32) {
+	span.SetTag(string(tag), value)
+}
+
+// ---
+
+type uint16TagName string
+
+// Set adds a uint16 tag to the `span`
+func (tag uint16TagName) Set(span opentracing.Span, value uint16) {
+	span.SetTag(string(tag), value)
+}
+
+// ---
+
+type boolTagName string
+
+// Add adds a bool tag to the `span`
+func (tag boolTagName) Set(span opentracing.Span, value bool) {
+	span.SetTag(string(tag), value)
+}
+
+type ipv4Tag string
+
+// Set adds IP v4 host address of the peer as an uint32 value to the `span`, keep this for backward and zipkin compatibility
+func (tag ipv4Tag) Set(span opentracing.Span, value uint32) {
+	span.SetTag(string(tag), value)
+}
+
+// SetString records IP v4 host address of the peer as a .-separated tuple to the `span`. E.g., "127.0.0.1"
+func (tag ipv4Tag) SetString(span opentracing.Span, value string) {
+	span.SetTag(string(tag), value)
+}

vendor/github.com/opentracing/opentracing-go/globaltracer.go

@@ -0,0 +1,32 @@
+package opentracing
+
+var (
+	globalTracer Tracer = NoopTracer{}
+)
+
+// SetGlobalTracer sets the [singleton] opentracing.Tracer returned by
+// GlobalTracer(). Those who use GlobalTracer (rather than directly manage an
+// opentracing.Tracer instance) should call SetGlobalTracer as early as
+// possible in main(), prior to calling the `StartSpan` global func below.
+// Prior to calling `SetGlobalTracer`, any Spans started via the `StartSpan`
+// (etc) globals are noops.
+func SetGlobalTracer(tracer Tracer) {
+	globalTracer = tracer
+}
+
+// GlobalTracer returns the global singleton `Tracer` implementation.
+// Before `SetGlobalTracer()` is called, the `GlobalTracer()` is a noop
+// implementation that drops all data handed to it.
+func GlobalTracer() Tracer {
+	return globalTracer
+}
+
+// StartSpan defers to `Tracer.StartSpan`. See `GlobalTracer()`.
+func StartSpan(operationName string, opts ...StartSpanOption) Span {
+	return globalTracer.StartSpan(operationName, opts...)
+}
+
+// InitGlobalTracer is deprecated. Please use SetGlobalTracer.
+func InitGlobalTracer(tracer Tracer) {
+	SetGlobalTracer(tracer)
+}

vendor/github.com/opentracing/opentracing-go/gocontext.go

@@ -0,0 +1,54 @@
+package opentracing
+
+import "context"
+
+type contextKey struct{}
+
+var activeSpanKey = contextKey{}
+
+// ContextWithSpan returns a new `context.Context` that holds a reference to
+// `span`'s SpanContext.
+func ContextWithSpan(ctx context.Context, span Span) context.Context {
+	return context.WithValue(ctx, activeSpanKey, span)
+}
+
+// SpanFromContext returns the `Span` previously associated with `ctx`, or
+// `nil` if no such `Span` could be found.
+//
+// NOTE: context.Context != SpanContext: the former is Go's intra-process
+// context propagation mechanism, and the latter houses OpenTracing's per-Span
+// identity and baggage information.
+func SpanFromContext(ctx context.Context) Span {
+	val := ctx.Value(activeSpanKey)
+	if sp, ok := val.(Span); ok {
+		return sp
+	}
+	return nil
+}
+
+// StartSpanFromContext starts and returns a Span with `operationName`, using
+// any Span found within `ctx` as a ChildOfRef. If no such parent could be
+// found, StartSpanFromContext creates a root (parentless) Span.
+//
+// The second return value is a context.Context object built around the
+// returned Span.
+//
+// Example usage:
+//
+//    SomeFunction(ctx context.Context, ...) {
+//        sp, ctx := opentracing.StartSpanFromContext(ctx, "SomeFunction")
+//        defer sp.Finish()
+//        ...
+//    }
+func StartSpanFromContext(ctx context.Context, operationName string, opts ...StartSpanOption) (Span, context.Context) {
+	return startSpanFromContextWithTracer(ctx, GlobalTracer(), operationName, opts...)
+}
+
+// startSpanFromContextWithTracer is factored out for testing purposes.
+func startSpanFromContextWithTracer(ctx context.Context, tracer Tracer, operationName string, opts ...StartSpanOption) (Span, context.Context) {
+	if parentSpan := SpanFromContext(ctx); parentSpan != nil {
+		opts = append(opts, ChildOf(parentSpan.Context()))
+	}
+	span := tracer.StartSpan(operationName, opts...)
+	return span, ContextWithSpan(ctx, span)
+}

vendor/github.com/opentracing/opentracing-go/log/field.go

@@ -0,0 +1,269 @@
+package log
+
+import (
+	"fmt"
+	"math"
+)
+
+type fieldType int
+
+const (
+	stringType fieldType = iota
+	boolType
+	intType
+	int32Type
+	uint32Type
+	int64Type
+	uint64Type
+	float32Type
+	float64Type
+	errorType
+	objectType
+	lazyLoggerType
+	noopType
+)
+
+// Field instances are constructed via LogBool, LogString, and so on.
+// Tracing implementations may then handle them via the Field.Marshal
+// method.
+//
+// "heavily influenced by" (i.e., partially stolen from)
+// https://github.com/uber-go/zap
+type Field struct {
+	key          string
+	fieldType    fieldType
+	numericVal   int64
+	stringVal    string
+	interfaceVal interface{}
+}
+
+// String adds a string-valued key:value pair to a Span.LogFields() record
+func String(key, val string) Field {
+	return Field{
+		key:       key,
+		fieldType: stringType,
+		stringVal: val,
+	}
+}
+
+// Bool adds a bool-valued key:value pair to a Span.LogFields() record
+func Bool(key string, val bool) Field {
+	var numericVal int64
+	if val {
+		numericVal = 1
+	}
+	return Field{
+		key:        key,
+		fieldType:  boolType,
+		numericVal: numericVal,
+	}
+}
+
+// Int adds an int-valued key:value pair to a Span.LogFields() record
+func Int(key string, val int) Field {
+	return Field{
+		key:        key,
+		fieldType:  intType,
+		numericVal: int64(val),
+	}
+}
+
+// Int32 adds an int32-valued key:value pair to a Span.LogFields() record
+func Int32(key string, val int32) Field {
+	return Field{
+		key:        key,
+		fieldType:  int32Type,
+		numericVal: int64(val),
+	}
+}
+
+// Int64 adds an int64-valued key:value pair to a Span.LogFields() record
+func Int64(key string, val int64) Field {
+	return Field{
+		key:        key,
+		fieldType:  int64Type,
+		numericVal: val,
+	}
+}
+
+// Uint32 adds a uint32-valued key:value pair to a Span.LogFields() record
+func Uint32(key string, val uint32) Field {
+	return Field{
+		key:        key,
+		fieldType:  uint32Type,
+		numericVal: int64(val),
+	}
+}
+
+// Uint64 adds a uint64-valued key:value pair to a Span.LogFields() record
+func Uint64(key string, val uint64) Field {
+	return Field{
+		key:        key,
+		fieldType:  uint64Type,
+		numericVal: int64(val),
+	}
+}
+
+// Float32 adds a float32-valued key:value pair to a Span.LogFields() record
+func Float32(key string, val float32) Field {
+	return Field{
+		key:        key,
+		fieldType:  float32Type,
+		numericVal: int64(math.Float32bits(val)),
+	}
+}
+
+// Float64 adds a float64-valued key:value pair to a Span.LogFields() record
+func Float64(key string, val float64) Field {
+	return Field{
+		key:        key,
+		fieldType:  float64Type,
+		numericVal: int64(math.Float64bits(val)),
+	}
+}
+
+// Error adds an error with the key "error" to a Span.LogFields() record
+func Error(err error) Field {
+	return Field{
+		key:          "error",
+		fieldType:    errorType,
+		interfaceVal: err,
+	}
+}
+
+// Object adds an object-valued key:value pair to a Span.LogFields() record
+func Object(key string, obj interface{}) Field {
+	return Field{
+		key:          key,
+		fieldType:    objectType,
+		interfaceVal: obj,
+	}
+}
+
+// LazyLogger allows for user-defined, late-bound logging of arbitrary data
+type LazyLogger func(fv Encoder)
+
+// Lazy adds a LazyLogger to a Span.LogFields() record; the tracing
+// implementation will call the LazyLogger function at an indefinite time in
+// the future (after Lazy() returns).
+func Lazy(ll LazyLogger) Field {
+	return Field{
+		fieldType:    lazyLoggerType,
+		interfaceVal: ll,
+	}
+}
+
+// Noop creates a no-op log field that should be ignored by the tracer.
+// It can be used to capture optional fields, for example those that should
+// only be logged in non-production environment:
+//
+//     func customerField(order *Order) log.Field {
+//          if os.Getenv("ENVIRONMENT") == "dev" {
+//              return log.String("customer", order.Customer.ID)
+//          }
+//          return log.Noop()
+//     }
+//
+//     span.LogFields(log.String("event", "purchase"), customerField(order))
+//
+func Noop() Field {
+	return Field{
+		fieldType: noopType,
+	}
+}
+
+// Encoder allows access to the contents of a Field (via a call to
+// Field.Marshal).
+//
+// Tracer implementations typically provide an implementation of Encoder;
+// OpenTracing callers typically do not need to concern themselves with it.
+type Encoder interface {
+	EmitString(key, value string)
+	EmitBool(key string, value bool)
+	EmitInt(key string, value int)
+	EmitInt32(key string, value int32)
+	EmitInt64(key string, value int64)
+	EmitUint32(key string, value uint32)
+	EmitUint64(key string, value uint64)
+	EmitFloat32(key string, value float32)
+	EmitFloat64(key string, value float64)
+	EmitObject(key string, value interface{})
+	EmitLazyLogger(value LazyLogger)
+}
+
+// Marshal passes a Field instance through to the appropriate
+// field-type-specific method of an Encoder.
+func (lf Field) Marshal(visitor Encoder) {
+	switch lf.fieldType {
+	case stringType:
+		visitor.EmitString(lf.key, lf.stringVal)
+	case boolType:
+		visitor.EmitBool(lf.key, lf.numericVal != 0)
+	case intType:
+		visitor.EmitInt(lf.key, int(lf.numericVal))
+	case int32Type:
+		visitor.EmitInt32(lf.key, int32(lf.numericVal))
+	case int64Type:
+		visitor.EmitInt64(lf.key, int64(lf.numericVal))
+	case uint32Type:
+		visitor.EmitUint32(lf.key, uint32(lf.numericVal))
+	case uint64Type:
+		visitor.EmitUint64(lf.key, uint64(lf.numericVal))
+	case float32Type:
+		visitor.EmitFloat32(lf.key, math.Float32frombits(uint32(lf.numericVal)))
+	case float64Type:
+		visitor.EmitFloat64(lf.key, math.Float64frombits(uint64(lf.numericVal)))
+	case errorType:
+		if err, ok := lf.interfaceVal.(error); ok {
+			visitor.EmitString(lf.key, err.Error())
+		} else {
+			visitor.EmitString(lf.key, "<nil>")
+		}
+	case objectType:
+		visitor.EmitObject(lf.key, lf.interfaceVal)
+	case lazyLoggerType:
+		visitor.EmitLazyLogger(lf.interfaceVal.(LazyLogger))
+	case noopType:
+		// intentionally left blank
+	}
+}
+
+// Key returns the field's key.
+func (lf Field) Key() string {
+	return lf.key
+}
+
+// Value returns the field's value as interface{}.
+func (lf Field) Value() interface{} {
+	switch lf.fieldType {
+	case stringType:
+		return lf.stringVal
+	case boolType:
+		return lf.numericVal != 0
+	case intType:
+		return int(lf.numericVal)
+	case int32Type:
+		return int32(lf.numericVal)
+	case int64Type:
+		return int64(lf.numericVal)
+	case uint32Type:
+		return uint32(lf.numericVal)
+	case uint64Type:
+		return uint64(lf.numericVal)
+	case float32Type:
+		return math.Float32frombits(uint32(lf.numericVal))
+	case float64Type:
+		return math.Float64frombits(uint64(lf.numericVal))
+	case errorType, objectType, lazyLoggerType:
+		return lf.interfaceVal
+	case noopType:
+		return nil
+	default:
+		return nil
+	}
+}
+
+// String returns a string representation of the key and value.
+func (lf Field) String() string {
+	return fmt.Sprint(lf.key, ":", lf.Value())
+}

vendor/github.com/opentracing/opentracing-go/log/util.go

@@ -0,0 +1,54 @@
+package log
+
+import "fmt"
+
+// InterleavedKVToFields converts keyValues a la Span.LogKV() to a Field slice
+// a la Span.LogFields().
+func InterleavedKVToFields(keyValues ...interface{}) ([]Field, error) {
+	if len(keyValues)%2 != 0 {
+		return nil, fmt.Errorf("non-even keyValues len: %d", len(keyValues))
+	}
+	fields := make([]Field, len(keyValues)/2)
+	for i := 0; i*2 < len(keyValues); i++ {
+		key, ok := keyValues[i*2].(string)
+		if !ok {
+			return nil, fmt.Errorf(
+				"non-string key (pair #%d): %T",
+				i, keyValues[i*2])
+		}
+		switch typedVal := keyValues[i*2+1].(type) {
+		case bool:
+			fields[i] = Bool(key, typedVal)
+		case string:
+			fields[i] = String(key, typedVal)
+		case int:
+			fields[i] = Int(key, typedVal)
+		case int8:
+			fields[i] = Int32(key, int32(typedVal))
+		case int16:
+			fields[i] = Int32(key, int32(typedVal))
+		case int32:
+			fields[i] = Int32(key, typedVal)
+		case int64:
+			fields[i] = Int64(key, typedVal)
+		case uint:
+			fields[i] = Uint64(key, uint64(typedVal))
+		case uint64:
+			fields[i] = Uint64(key, typedVal)
+		case uint8:
+			fields[i] = Uint32(key, uint32(typedVal))
+		case uint16:
+			fields[i] = Uint32(key, uint32(typedVal))
+		case uint32:
+			fields[i] = Uint32(key, typedVal)
+		case float32:
+			fields[i] = Float32(key, typedVal)
+		case float64:
+			fields[i] = Float64(key, typedVal)
+		default:
+			// When in doubt, coerce to a string
+			fields[i] = String(key, fmt.Sprint(typedVal))
+		}
+	}
+	return fields, nil
+}

vendor/github.com/opentracing/opentracing-go/noop.go

@@ -0,0 +1,64 @@
+package opentracing
+
+import "github.com/opentracing/opentracing-go/log"
+
+// A NoopTracer is a trivial, minimum overhead implementation of Tracer
+// for which all operations are no-ops.
+//
+// The primary use of this implementation is in libraries, such as RPC
+// frameworks, that make tracing an optional feature controlled by the
+// end user. A no-op implementation allows said libraries to use it
+// as the default Tracer and to write instrumentation that does
+// not need to keep checking if the tracer instance is nil.
+//
+// For the same reason, the NoopTracer is the default "global" tracer
+// (see GlobalTracer and SetGlobalTracer functions).
+//
+// WARNING: NoopTracer does not support baggage propagation.
+type NoopTracer struct{}
+
+type noopSpan struct{}
+type noopSpanContext struct{}
+
+var (
+	defaultNoopSpanContext = noopSpanContext{}
+	defaultNoopSpan        = noopSpan{}
+	defaultNoopTracer      = NoopTracer{}
+)
+
+const (
+	emptyString = ""
+)
+
+// noopSpanContext:
+func (n noopSpanContext) ForeachBaggageItem(handler func(k, v string) bool) {}
+
+// noopSpan:
+func (n noopSpan) Context() SpanContext                                  { return defaultNoopSpanContext }
+func (n noopSpan) SetBaggageItem(key, val string) Span                   { return defaultNoopSpan }
+func (n noopSpan) BaggageItem(key string) string                         { return emptyString }
+func (n noopSpan) SetTag(key string, value interface{}) Span             { return n }
+func (n noopSpan) LogFields(fields ...log.Field)                         {}
+func (n noopSpan) LogKV(keyVals ...interface{})                          {}
+func (n noopSpan) Finish()                                               {}
+func (n noopSpan) FinishWithOptions(opts FinishOptions)                  {}
+func (n noopSpan) SetOperationName(operationName string) Span            { return n }
+func (n noopSpan) Tracer() Tracer                                        { return defaultNoopTracer }
+func (n noopSpan) LogEvent(event string)                                 {}
+func (n noopSpan) LogEventWithPayload(event string, payload interface{}) {}
+func (n noopSpan) Log(data LogData)                                      {}
+
+// StartSpan belongs to the Tracer interface.
+func (n NoopTracer) StartSpan(operationName string, opts ...StartSpanOption) Span {
+	return defaultNoopSpan
+}
+
+// Inject belongs to the Tracer interface.
+func (n NoopTracer) Inject(sp SpanContext, format interface{}, carrier interface{}) error {
+	return nil
+}
+
+// Extract belongs to the Tracer interface.
+func (n NoopTracer) Extract(format interface{}, carrier interface{}) (SpanContext, error) {
+	return nil, ErrSpanContextNotFound
+}

vendor/github.com/opentracing/opentracing-go/propagation.go

@@ -0,0 +1,176 @@
+package opentracing
+
+import (
+	"errors"
+	"net/http"
+)
+
+///////////////////////////////////////////////////////////////////////////////
+// CORE PROPAGATION INTERFACES:
+///////////////////////////////////////////////////////////////////////////////
+
+var (
+	// ErrUnsupportedFormat occurs when the `format` passed to Tracer.Inject() or
+	// Tracer.Extract() is not recognized by the Tracer implementation.
+	ErrUnsupportedFormat = errors.New("opentracing: Unknown or unsupported Inject/Extract format")
+
+	// ErrSpanContextNotFound occurs when the `carrier` passed to
+	// Tracer.Extract() is valid and uncorrupted but has insufficient
+	// information to extract a SpanContext.
+	ErrSpanContextNotFound = errors.New("opentracing: SpanContext not found in Extract carrier")
+
+	// ErrInvalidSpanContext errors occur when Tracer.Inject() is asked to
+	// operate on a SpanContext which it is not prepared to handle (for
+	// example, since it was created by a different tracer implementation).
+	ErrInvalidSpanContext = errors.New("opentracing: SpanContext type incompatible with tracer")
+
+	// ErrInvalidCarrier errors occur when Tracer.Inject() or Tracer.Extract()
+	// implementations expect a different type of `carrier` than they are
+	// given.
+	ErrInvalidCarrier = errors.New("opentracing: Invalid Inject/Extract carrier")
+
+	// ErrSpanContextCorrupted occurs when the `carrier` passed to
+	// Tracer.Extract() is of the expected type but is corrupted.
+	ErrSpanContextCorrupted = errors.New("opentracing: SpanContext data corrupted in Extract carrier")
+)
+
+///////////////////////////////////////////////////////////////////////////////
+// BUILTIN PROPAGATION FORMATS:
+///////////////////////////////////////////////////////////////////////////////
+
+// BuiltinFormat is used to demarcate the values within package `opentracing`
+// that are intended for use with the Tracer.Inject() and Tracer.Extract()
+// methods.
+type BuiltinFormat byte
+
+const (
+	// Binary represents SpanContexts as opaque binary data.
+	//
+	// For Tracer.Inject(): the carrier must be an `io.Writer`.
+	//
+	// For Tracer.Extract(): the carrier must be an `io.Reader`.
+	Binary BuiltinFormat = iota
+
+	// TextMap represents SpanContexts as key:value string pairs.
+	//
+	// Unlike HTTPHeaders, the TextMap format does not restrict the key or
+	// value character sets in any way.
+	//
+	// For Tracer.Inject(): the carrier must be a `TextMapWriter`.
+	//
+	// For Tracer.Extract(): the carrier must be a `TextMapReader`.
+	TextMap
+
+	// HTTPHeaders represents SpanContexts as HTTP header string pairs.
+	//
+	// Unlike TextMap, the HTTPHeaders format requires that the keys and values
+	// be valid as HTTP headers as-is (i.e., character casing may be unstable
+	// and special characters are disallowed in keys, values should be
+	// URL-escaped, etc).
+	//
+	// For Tracer.Inject(): the carrier must be a `TextMapWriter`.
+	//
+	// For Tracer.Extract(): the carrier must be a `TextMapReader`.
+	//
+	// See HTTPHeadersCarrier for an implementation of both TextMapWriter
+	// and TextMapReader that defers to an http.Header instance for storage.
+	// For example, Inject():
+	//
+	//    carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+	//    err := span.Tracer().Inject(
+	//        span.Context(), opentracing.HTTPHeaders, carrier)
+	//
+	// Or Extract():
+	//
+	//    carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+	//    clientContext, err := tracer.Extract(
+	//        opentracing.HTTPHeaders, carrier)
+	//
+	HTTPHeaders
+)
+
+// TextMapWriter is the Inject() carrier for the TextMap builtin format. With
+// it, the caller can encode a SpanContext for propagation as entries in a map
+// of unicode strings.
+type TextMapWriter interface {
+	// Set a key:value pair to the carrier. Multiple calls to Set() for the
+	// same key leads to undefined behavior.
+	//
+	// NOTE: The backing store for the TextMapWriter may contain data unrelated
+	// to SpanContext. As such, Inject() and Extract() implementations that
+	// call the TextMapWriter and TextMapReader interfaces must agree on a
+	// prefix or other convention to distinguish their own key:value pairs.
+	Set(key, val string)
+}
+
+// TextMapReader is the Extract() carrier for the TextMap builtin format. With it,
+// the caller can decode a propagated SpanContext as entries in a map of
+// unicode strings.
+type TextMapReader interface {
+	// ForeachKey returns TextMap contents via repeated calls to the `handler`
+	// function. If any call to `handler` returns a non-nil error, ForeachKey
+	// terminates and returns that error.
+	//
+	// NOTE: The backing store for the TextMapReader may contain data unrelated
+	// to SpanContext. As such, Inject() and Extract() implementations that
+	// call the TextMapWriter and TextMapReader interfaces must agree on a
+	// prefix or other convention to distinguish their own key:value pairs.
+	//
+	// The "foreach" callback pattern reduces unnecessary copying in some cases
+	// and also allows implementations to hold locks while the map is read.
+	ForeachKey(handler func(key, val string) error) error
+}
+
+// TextMapCarrier allows the use of regular map[string]string
+// as both TextMapWriter and TextMapReader.
+type TextMapCarrier map[string]string
+
+// ForeachKey conforms to the TextMapReader interface.
+func (c TextMapCarrier) ForeachKey(handler func(key, val string) error) error {
+	for k, v := range c {
+		if err := handler(k, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Set implements Set() of opentracing.TextMapWriter
+func (c TextMapCarrier) Set(key, val string) {
+	c[key] = val
+}
+
+// HTTPHeadersCarrier satisfies both TextMapWriter and TextMapReader.
+//
+// Example usage for server side:
+//
+//     carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+//     clientContext, err := tracer.Extract(opentracing.HTTPHeaders, carrier)
+//
+// Example usage for client side:
+//
+//     carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+//     err := tracer.Inject(
+//         span.Context(),
+//         opentracing.HTTPHeaders,
+//         carrier)
+//
+type HTTPHeadersCarrier http.Header
+
+// Set conforms to the TextMapWriter interface.
+func (c HTTPHeadersCarrier) Set(key, val string) {
+	h := http.Header(c)
+	h.Add(key, val)
+}
+
+// ForeachKey conforms to the TextMapReader interface.
+func (c HTTPHeadersCarrier) ForeachKey(handler func(key, val string) error) error {
+	for k, vals := range c {
+		for _, v := range vals {
+			if err := handler(k, v); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

vendor/github.com/opentracing/opentracing-go/span.go

@@ -0,0 +1,189 @@
+package opentracing
+
+import (
+	"time"
+
+	"github.com/opentracing/opentracing-go/log"
+)
+
+// SpanContext represents Span state that must propagate to descendant Spans and across process
+// boundaries (e.g., a <trace_id, span_id, sampled> tuple).
+type SpanContext interface {
+	// ForeachBaggageItem grants access to all baggage items stored in the
+	// SpanContext.
+	// The handler function will be called for each baggage key/value pair.
+	// The ordering of items is not guaranteed.
+	//
+	// The bool return value indicates if the handler wants to continue iterating
+	// through the rest of the baggage items; for example if the handler is trying to
+	// find some baggage item by pattern matching the name, it can return false
+	// as soon as the item is found to stop further iterations.
+	ForeachBaggageItem(handler func(k, v string) bool)
+}
+
+// Span represents an active, un-finished span in the OpenTracing system.
+//
+// Spans are created by the Tracer interface.
+type Span interface {
+	// Sets the end timestamp and finalizes Span state.
+	//
+	// With the exception of calls to Context() (which are always allowed),
+	// Finish() must be the last call made to any span instance, and to do
+	// otherwise leads to undefined behavior.
+	Finish()
+	// FinishWithOptions is like Finish() but with explicit control over
+	// timestamps and log data.
+	FinishWithOptions(opts FinishOptions)
+
+	// Context() yields the SpanContext for this Span. Note that the return
+	// value of Context() is still valid after a call to Span.Finish(), as is
+	// a call to Span.Context() after a call to Span.Finish().
+	Context() SpanContext
+
+	// Sets or changes the operation name.
+	//
+	// Returns a reference to this Span for chaining.
+	SetOperationName(operationName string) Span
+
+	// Adds a tag to the span.
+	//
+	// If there is a pre-existing tag set for `key`, it is overwritten.
+	//
+	// Tag values can be numeric types, strings, or bools. The behavior of
+	// other tag value types is undefined at the OpenTracing level. If a
+	// tracing system does not know how to handle a particular value type, it
+	// may ignore the tag, but shall not panic.
+	//
+	// Returns a reference to this Span for chaining.
+	SetTag(key string, value interface{}) Span
+
+	// LogFields is an efficient and type-checked way to record key:value
+	// logging data about a Span, though the programming interface is a little
+	// more verbose than LogKV(). Here's an example:
+	//
+	//    span.LogFields(
+	//        log.String("event", "soft error"),
+	//        log.String("type", "cache timeout"),
+	//        log.Int("waited.millis", 1500))
+	//
+	// Also see Span.FinishWithOptions() and FinishOptions.BulkLogData.
+	LogFields(fields ...log.Field)
+
+	// LogKV is a concise, readable way to record key:value logging data about
+	// a Span, though unfortunately this also makes it less efficient and less
+	// type-safe than LogFields(). Here's an example:
+	//
+	//    span.LogKV(
+	//        "event", "soft error",
+	//        "type", "cache timeout",
+	//        "waited.millis", 1500)
+	//
+	// For LogKV (as opposed to LogFields()), the parameters must appear as
+	// key-value pairs, like
+	//
+	//    span.LogKV(key1, val1, key2, val2, key3, val3, ...)
+	//
+	// The keys must all be strings. The values may be strings, numeric types,
+	// bools, Go error instances, or arbitrary structs.
+	//
+	// (Note to implementors: consider the log.InterleavedKVToFields() helper)
+	LogKV(alternatingKeyValues ...interface{})
+
+	// SetBaggageItem sets a key:value pair on this Span and its SpanContext
+	// that also propagates to descendants of this Span.
+	//
+	// SetBaggageItem() enables powerful functionality given a full-stack
+	// opentracing integration (e.g., arbitrary application data from a mobile
+	// app can make it, transparently, all the way into the depths of a storage
+	// system), and with it some powerful costs: use this feature with care.
+	//
+	// IMPORTANT NOTE #1: SetBaggageItem() will only propagate baggage items to
+	// *future* causal descendants of the associated Span.
+	//
+	// IMPORTANT NOTE #2: Use this thoughtfully and with care. Every key and
+	// value is copied into every local *and remote* child of the associated
+	// Span, and that can add up to a lot of network and cpu overhead.
+	//
+	// Returns a reference to this Span for chaining.
+	SetBaggageItem(restrictedKey, value string) Span
+
+	// Gets the value for a baggage item given its key. Returns the empty string
+	// if the value isn't found in this Span.
+	BaggageItem(restrictedKey string) string
+
+	// Provides access to the Tracer that created this Span.
+	Tracer() Tracer
+
+	// Deprecated: use LogFields or LogKV
+	LogEvent(event string)
+	// Deprecated: use LogFields or LogKV
+	LogEventWithPayload(event string, payload interface{})
+	// Deprecated: use LogFields or LogKV
+	Log(data LogData)
+}
+
+// LogRecord is data associated with a single Span log. Every LogRecord
+// instance must specify at least one Field.
+type LogRecord struct {
+	Timestamp time.Time
+	Fields    []log.Field
+}
+
+// FinishOptions allows Span.FinishWithOptions callers to override the finish
+// timestamp and provide log data via a bulk interface.
+type FinishOptions struct {
+	// FinishTime overrides the Span's finish time, or implicitly becomes
+	// time.Now() if FinishTime.IsZero().
+	//
+	// FinishTime must resolve to a timestamp that's >= the Span's StartTime
+	// (per StartSpanOptions).
+	FinishTime time.Time
+
+	// LogRecords allows the caller to specify the contents of many LogFields()
+	// calls with a single slice. May be nil.
+	//
+	// None of the LogRecord.Timestamp values may be .IsZero() (i.e., they must
+	// be set explicitly). Also, they must be >= the Span's start timestamp and
+	// <= the FinishTime (or time.Now() if FinishTime.IsZero()). Otherwise the
+	// behavior of FinishWithOptions() is undefined.
+	//
+	// If specified, the caller hands off ownership of LogRecords at
+	// FinishWithOptions() invocation time.
+	//
+	// If specified, the (deprecated) BulkLogData must be nil or empty.
+	LogRecords []LogRecord
+
+	// BulkLogData is DEPRECATED.
+	BulkLogData []LogData
+}
+
+// LogData is DEPRECATED
+type LogData struct {
+	Timestamp time.Time
+	Event     string
+	Payload   interface{}
+}
+
+// ToLogRecord converts a deprecated LogData to a non-deprecated LogRecord
+func (ld *LogData) ToLogRecord() LogRecord {
+	var literalTimestamp time.Time
+	if ld.Timestamp.IsZero() {
+		literalTimestamp = time.Now()
+	} else {
+		literalTimestamp = ld.Timestamp
+	}
+	rval := LogRecord{
+		Timestamp: literalTimestamp,
+	}
+	if ld.Payload == nil {
+		rval.Fields = []log.Field{
+			log.String("event", ld.Event),
+		}
+	} else {
+		rval.Fields = []log.Field{
+			log.String("event", ld.Event),
+			log.Object("payload", ld.Payload),
+		}
+	}
+	return rval
+}

vendor/github.com/opentracing/opentracing-go/tracer.go

@@ -0,0 +1,305 @@
+package opentracing
+
+import "time"
+
+// Tracer is a simple, thin interface for Span creation and SpanContext
+// propagation.
+type Tracer interface {
+
+	// Create, start, and return a new Span with the given `operationName` and
+	// incorporate the given StartSpanOption `opts`. (Note that `opts` borrows
+	// from the "functional options" pattern, per
+	// http://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis)
+	//
+	// A Span with no SpanReference options (e.g., opentracing.ChildOf() or
+	// opentracing.FollowsFrom()) becomes the root of its own trace.
+	//
+	// Examples:
+	//
+	//     var tracer opentracing.Tracer = ...
+	//
+	//     // The root-span case:
+	//     sp := tracer.StartSpan("GetFeed")
+	//
+	//     // The vanilla child span case:
+	//     sp := tracer.StartSpan(
+	//         "GetFeed",
+	//         opentracing.ChildOf(parentSpan.Context()))
+	//
+	//     // All the bells and whistles:
+	//     sp := tracer.StartSpan(
+	//         "GetFeed",
+	//         opentracing.ChildOf(parentSpan.Context()),
+	//         opentracing.Tag{"user_agent", loggedReq.UserAgent},
+	//         opentracing.StartTime(loggedReq.Timestamp),
+	//     )
+	//
+	StartSpan(operationName string, opts ...StartSpanOption) Span
+
+	// Inject() takes the `sm` SpanContext instance and injects it for
+	// propagation within `carrier`. The actual type of `carrier` depends on
+	// the value of `format`.
+	//
+	// OpenTracing defines a common set of `format` values (see BuiltinFormat),
+	// and each has an expected carrier type.
+	//
+	// Other packages may declare their own `format` values, much like the keys
+	// used by `context.Context` (see
+	// https://godoc.org/golang.org/x/net/context#WithValue).
+	//
+	// Example usage (sans error handling):
+	//
+	//     carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+	//     err := tracer.Inject(
+	//         span.Context(),
+	//         opentracing.HTTPHeaders,
+	//         carrier)
+	//
+	// NOTE: All opentracing.Tracer implementations MUST support all
+	// BuiltinFormats.
+	//
+	// Implementations may return opentracing.ErrUnsupportedFormat if `format`
+	// is not supported by (or not known by) the implementation.
+	//
+	// Implementations may return opentracing.ErrInvalidCarrier or any other
+	// implementation-specific error if the format is supported but injection
+	// fails anyway.
+	//
+	// See Tracer.Extract().
+	Inject(sm SpanContext, format interface{}, carrier interface{}) error
+
+	// Extract() returns a SpanContext instance given `format` and `carrier`.
+	//
+	// OpenTracing defines a common set of `format` values (see BuiltinFormat),
+	// and each has an expected carrier type.
+	//
+	// Other packages may declare their own `format` values, much like the keys
+	// used by `context.Context` (see
+	// https://godoc.org/golang.org/x/net/context#WithValue).
+	//
+	// Example usage (with StartSpan):
+	//
+	//
+	//     carrier := opentracing.HTTPHeadersCarrier(httpReq.Header)
+	//     clientContext, err := tracer.Extract(opentracing.HTTPHeaders, carrier)
+	//
+	//     // ... assuming the ultimate goal here is to resume the trace with a
+	//     // server-side Span:
+	//     var serverSpan opentracing.Span
+	//     if err == nil {
+	//         span = tracer.StartSpan(
+	//             rpcMethodName, ext.RPCServerOption(clientContext))
+	//     } else {
+	//         span = tracer.StartSpan(rpcMethodName)
+	//     }
+	//
+	//
+	// NOTE: All opentracing.Tracer implementations MUST support all
+	// BuiltinFormats.
+	//
+	// Return values:
+	//  - A successful Extract returns a SpanContext instance and a nil error
+	//  - If there was simply no SpanContext to extract in `carrier`, Extract()
+	//    returns (nil, opentracing.ErrSpanContextNotFound)
+	//  - If `format` is unsupported or unrecognized, Extract() returns (nil,
+	//    opentracing.ErrUnsupportedFormat)
+	//  - If there are more fundamental problems with the `carrier` object,
+	//    Extract() may return opentracing.ErrInvalidCarrier,
+	//    opentracing.ErrSpanContextCorrupted, or implementation-specific
+	//    errors.
+	//
+	// See Tracer.Inject().
+	Extract(format interface{}, carrier interface{}) (SpanContext, error)
+}
+
+// StartSpanOptions allows Tracer.StartSpan() callers and implementors a
+// mechanism to override the start timestamp, specify Span References, and make
+// a single Tag or multiple Tags available at Span start time.
+//
+// StartSpan() callers should look at the StartSpanOption interface and
+// implementations available in this package.
+//
+// Tracer implementations can convert a slice of `StartSpanOption` instances
+// into a `StartSpanOptions` struct like so:
+//
+//     func StartSpan(opName string, opts ...opentracing.StartSpanOption) {
+//         sso := opentracing.StartSpanOptions{}
+//         for _, o := range opts {
+//             o.Apply(&sso)
+//         }
+//         ...
+//     }
+//
+type StartSpanOptions struct {
+	// Zero or more causal references to other Spans (via their SpanContext).
+	// If empty, start a "root" Span (i.e., start a new trace).
+	References []SpanReference
+
+	// StartTime overrides the Span's start time, or implicitly becomes
+	// time.Now() if StartTime.IsZero().
+	StartTime time.Time
+
+	// Tags may have zero or more entries; the restrictions on map values are
+	// identical to those for Span.SetTag(). May be nil.
+	//
+	// If specified, the caller hands off ownership of Tags at
+	// StartSpan() invocation time.
+	Tags map[string]interface{}
+}
+
+// StartSpanOption instances (zero or more) may be passed to Tracer.StartSpan.
+//
+// StartSpanOption borrows from the "functional options" pattern, per
+// http://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis
+type StartSpanOption interface {
+	Apply(*StartSpanOptions)
+}
+
+// SpanReferenceType is an enum type describing different categories of
+// relationships between two Spans. If Span-2 refers to Span-1, the
+// SpanReferenceType describes Span-1 from Span-2's perspective. For example,
+// ChildOfRef means that Span-1 created Span-2.
+//
+// NOTE: Span-1 and Span-2 do *not* necessarily depend on each other for
+// completion; e.g., Span-2 may be part of a background job enqueued by Span-1,
+// or Span-2 may be sitting in a distributed queue behind Span-1.
+type SpanReferenceType int
+
+const (
+	// ChildOfRef refers to a parent Span that caused *and* somehow depends
+	// upon the new child Span. Often (but not always), the parent Span cannot
+	// finish until the child Span does.
+	//
+	// An timing diagram for a ChildOfRef that's blocked on the new Span:
+	//
+	//     [-Parent Span---------]
+	//          [-Child Span----]
+	//
+	// See http://opentracing.io/spec/
+	//
+	// See opentracing.ChildOf()
+	ChildOfRef SpanReferenceType = iota
+
+	// FollowsFromRef refers to a parent Span that does not depend in any way
+	// on the result of the new child Span. For instance, one might use
+	// FollowsFromRefs to describe pipeline stages separated by queues,
+	// or a fire-and-forget cache insert at the tail end of a web request.
+	//
+	// A FollowsFromRef Span is part of the same logical trace as the new Span:
+	// i.e., the new Span is somehow caused by the work of its FollowsFromRef.
+	//
+	// All of the following could be valid timing diagrams for children that
+	// "FollowFrom" a parent.
+	//
+	//     [-Parent Span-]  [-Child Span-]
+	//
+	//
+	//     [-Parent Span--]
+	//      [-Child Span-]
+	//
+	//
+	//     [-Parent Span-]
+	//                 [-Child Span-]
+	//
+	// See http://opentracing.io/spec/
+	//
+	// See opentracing.FollowsFrom()
+	FollowsFromRef
+)
+
+// SpanReference is a StartSpanOption that pairs a SpanReferenceType and a
+// referenced SpanContext. See the SpanReferenceType documentation for
+// supported relationships.  If SpanReference is created with
+// ReferencedContext==nil, it has no effect. Thus it allows for a more concise
+// syntax for starting spans:
+//
+//     sc, _ := tracer.Extract(someFormat, someCarrier)
+//     span := tracer.StartSpan("operation", opentracing.ChildOf(sc))
+//
+// The `ChildOf(sc)` option above will not panic if sc == nil, it will just
+// not add the parent span reference to the options.
+type SpanReference struct {
+	Type              SpanReferenceType
+	ReferencedContext SpanContext
+}
+
+// Apply satisfies the StartSpanOption interface.
+func (r SpanReference) Apply(o *StartSpanOptions) {
+	if r.ReferencedContext != nil {
+		o.References = append(o.References, r)
+	}
+}
+
+// ChildOf returns a StartSpanOption pointing to a dependent parent span.
+// If sc == nil, the option has no effect.
+//
+// See ChildOfRef, SpanReference
+func ChildOf(sc SpanContext) SpanReference {
+	return SpanReference{
+		Type:              ChildOfRef,
+		ReferencedContext: sc,
+	}
+}
+
+// FollowsFrom returns a StartSpanOption pointing to a parent Span that caused
+// the child Span but does not directly depend on its result in any way.
+// If sc == nil, the option has no effect.
+//
+// See FollowsFromRef, SpanReference
+func FollowsFrom(sc SpanContext) SpanReference {
+	return SpanReference{
+		Type:              FollowsFromRef,
+		ReferencedContext: sc,
+	}
+}
+
+// StartTime is a StartSpanOption that sets an explicit start timestamp for the
+// new Span.
+type StartTime time.Time
+
+// Apply satisfies the StartSpanOption interface.
+func (t StartTime) Apply(o *StartSpanOptions) {
+	o.StartTime = time.Time(t)
+}
+
+// Tags are a generic map from an arbitrary string key to an opaque value type.
+// The underlying tracing system is responsible for interpreting and
+// serializing the values.
+type Tags map[string]interface{}
+
+// Apply satisfies the StartSpanOption interface.
+func (t Tags) Apply(o *StartSpanOptions) {
+	if o.Tags == nil {
+		o.Tags = make(map[string]interface{})
+	}
+	for k, v := range t {
+		o.Tags[k] = v
+	}
+}
+
+// Tag may be passed as a StartSpanOption to add a tag to new spans,
+// or its Set method may be used to apply the tag to an existing Span,
+// for example:
+//
+// tracer.StartSpan("opName", Tag{"Key", value})
+//
+//   or
+//
+// Tag{"key", value}.Set(span)
+type Tag struct {
+	Key   string
+	Value interface{}
+}
+
+// Apply satisfies the StartSpanOption interface.
+func (t Tag) Apply(o *StartSpanOptions) {
+	if o.Tags == nil {
+		o.Tags = make(map[string]interface{})
+	}
+	o.Tags[t.Key] = t.Value
+}
+
+// Set applies the tag to an existing Span.
+func (t Tag) Set(s Span) {
+	s.SetTag(t.Key, t.Value)
+}

vendor/github.com/uber/jaeger-client-go/CHANGELOG.md

@@ -0,0 +1,186 @@
+Changes by Version
+==================
+
+2.15.0 (unreleased)
+-------------------
+
+- nothing yet
+
+
+2.14.0 (2018-04-30)
+-------------------
+
+- Support throttling for debug traces (#274) <Isaac Hier>
+- Remove dependency on Apache Thrift (#303) <Yuri Shkuro>
+- Remove dependency on tchannel  (#295) (#294) <Yuri Shkuro>
+- Test with Go 1.9 (#298) <Yuri Shkuro>
+
+
+2.13.0 (2018-04-15)
+-------------------
+
+- Use value receiver for config.NewTracer() (#283) <Yuri Shkuro>
+- Lock span during jaeger thrift conversion (#273) <Won Jun Jang>
+- Fix the RemotelyControlledSampler so that it terminates go-routine on Close() (#260) <Scott Kidder> <Yuri Shkuro>
+- Added support for client configuration via env vars (#275) <Juraci Paixão Kröhling>
+- Allow overriding sampler in the Config (#270) <Mike Kabischev>
+
+
+2.12.0 (2018-03-14)
+-------------------
+
+- Use lock when retrieving span.Context() (#268)
+- Add Configuration support for custom Injector and Extractor (#263) <Martin Liu>
+
+
+2.11.2 (2018-01-12)
+-------------------
+
+- Add Gopkg.toml to allow using the lib with `dep`
+
+
+2.11.1 (2018-01-03)
+-------------------
+
+- Do not enqueue spans after Reporter is closed (#235, #245)
+- Change default flush interval to 1sec (#243)
+
+
+2.11.0 (2017-11-27)
+-------------------
+
+- Normalize metric names and tags to be compatible with Prometheus (#222)
+
+
+2.10.0 (2017-11-14)
+-------------------
+
+- Support custom tracing headers (#176)
+- Add BaggageRestrictionManager (#178) and RemoteBaggageRestrictionManager (#182)
+- Do not coerce baggage keys to lower case (#196)
+- Log span name when span cannot be reported (#198)
+- Add option to enable gen128Bit for tracer (#193) and allow custom generator for high bits of trace ID (#219)
+
+
+2.9.0 (2017-07-29)
+------------------
+
+- Pin thrift <= 0.10 (#179)
+- Introduce a parallel interface ContribObserver (#159)
+
+
+2.8.0 (2017-07-05)
+------------------
+
+- Drop `jaeger.` prefix from `jaeger.hostname` process-level tag
+- Add options to set tracer tags
+
+
+2.7.0 (2017-06-21)
+------------------
+
+- Fix rate limiter balance [#135](https://github.com/uber/jaeger-client-go/pull/135) [#140](https://github.com/uber/jaeger-client-go/pull/140)
+- Default client to send Jaeger.thrift [#147](https://github.com/uber/jaeger-client-go/pull/147)
+- Save baggage in span [#153](https://github.com/uber/jaeger-client-go/pull/153)
+- Move reporter.queueLength to the top of the struct to guarantee 64bit alignment [#158](https://github.com/uber/jaeger-client-go/pull/158)
+- Support HTTP transport with jaeger.thrift [#161](https://github.com/uber/jaeger-client-go/pull/161)
+
+
+2.6.0 (2017-03-28)
+------------------
+
+- Add config option to initialize RPC Metrics feature
+
+
+2.5.0 (2017-03-23)
+------------------
+
+- Split request latency metric by success/failure [#123](https://github.com/uber/jaeger-client-go/pull/123)
+- Add mutex to adaptive sampler and fix race condition [#124](https://github.com/uber/jaeger-client-go/pull/124)
+- Fix rate limiter panic [#125](https://github.com/uber/jaeger-client-go/pull/125)
+
+
+2.4.0 (2017-03-21)
+------------------
+
+- Remove `_ms` suffix from request latency metric name [#121](https://github.com/uber/jaeger-client-go/pull/121)
+- Rename all metrics to "request" and "http_request" and use tags for other dimensions [#121](https://github.com/uber/jaeger-client-go/pull/121)
+
+
+2.3.0 (2017-03-20)
+------------------
+
+- Make Span type public to allow access to non-std methods for testing [#117](https://github.com/uber/jaeger-client-go/pull/117)
+- Add a structured way to extract traces for logging with zap [#118](https://github.com/uber/jaeger-client-go/pull/118)
+
+
+2.2.1 (2017-03-14)
+------------------
+
+- Fix panic caused by updating the remote sampler from adaptive sampler to any other sampler type (https://github.com/uber/jaeger-client-go/pull/111)
+
+
+2.2.0 (2017-03-10)
+------------------
+
+- Introduce Observer and SpanObserver (https://github.com/uber/jaeger-client-go/pull/94)
+- Add RPC metrics emitter as Observer/SpanObserver (https://github.com/uber/jaeger-client-go/pull/103)
+
+
+2.1.2 (2017-02-27)
+-------------------
+
+- Fix leaky bucket bug (https://github.com/uber/jaeger-client-go/pull/99)
+- Fix zap logger Infof (https://github.com/uber/jaeger-client-go/pull/100)
+- Add tracer initialization godoc examples
+
+
+2.1.1 (2017-02-21)
+-------------------
+
+- Fix inefficient usage of zap.Logger
+
+
+2.1.0 (2017-02-17)
+-------------------
+
+- Add adapter for zap.Logger (https://github.com/uber-go/zap)
+- Move logging API to ./log/ package
+
+
+2.0.0 (2017-02-08)
+-------------------
+
+- Support Adaptive Sampling
+- Support 128bit Trace IDs
+- Change trace/span IDs from uint64 to strong types TraceID and SpanID
+- Add Zipkin HTTP B3 Propagation format support #72
+- Rip out existing metrics and use github.com/uber/jaeger-lib/metrics
+- Change API for tracer, reporter, sampler initialization
+
+
+1.6.0 (2016-10-14)
+-------------------
+
+- Add Zipkin HTTP transport
+- Support external baggage via jaeger-baggage header
+- Unpin Thrift version, keep to master
+
+
+1.5.1 (2016-09-27)
+-------------------
+
+- Relax dependency on opentracing to ^1
+
+
+1.5.0 (2016-09-27)
+-------------------
+
+- Upgrade to opentracing-go 1.0
+- Support KV logging for Spans
+
+
+1.4.0 (2016-09-14)
+-------------------
+
+- Support debug traces via HTTP header "jaeger-debug-id"

vendor/github.com/uber/jaeger-client-go/CONTRIBUTING.md

@@ -0,0 +1,170 @@
+# How to Contribute to Jaeger
+
+We'd love your help!
+
+Jaeger is [Apache 2.0 licensed](LICENSE) and accepts contributions via GitHub
+pull requests. This document outlines some of the conventions on development
+workflow, commit message formatting, contact points and other resources to make
+it easier to get your contribution accepted.
+
+We gratefully welcome improvements to documentation as well as to code.
+
+# Certificate of Origin
+
+By contributing to this project you agree to the [Developer Certificate of
+Origin](https://developercertificate.org/) (DCO). This document was created
+by the Linux Kernel community and is a simple statement that you, as a
+contributor, have the legal right to make the contribution. See the [DCO](DCO)
+file for details.
+
+## Getting Started
+
+This library uses [glide](https://github.com/Masterminds/glide) to manage dependencies.
+
+To get started, make sure you clone the Git repository into the correct location
+`github.com/uber/jaeger-client-go` relative to `$GOPATH`:
+
+```
+mkdir -p $GOPATH/src/github.com/uber
+cd $GOPATH/src/github.com/uber
+git clone git@github.com:jaegertracing/jaeger-client-go.git jaeger-client-go
+cd jaeger-client-go
+```
+
+Then install dependencies and run the tests:
+
+```
+git submodule update --init --recursive
+glide install
+make test
+```
+
+## Imports grouping
+
+This projects follows the following pattern for grouping imports in Go files:
+  * imports from standard library
+  * imports from other projects
+  * imports from `jaeger-client-go` project
+  
+For example:
+
+```go
+import (
+	"fmt"
+ 
+	"github.com/uber/jaeger-lib/metrics"
+	"go.uber.org/zap"
+
+	"github.com/uber/jaeger-client-go/config"
+)
+```
+
+## Making A Change
+
+*Before making any significant changes, please [open an
+issue](https://github.com/jaegertracing/jaeger-client-go/issues).* Discussing your proposed
+changes ahead of time will make the contribution process smooth for everyone.
+
+Once we've discussed your changes and you've got your code ready, make sure
+that tests are passing (`make test` or `make cover`) and open your PR. Your
+pull request is most likely to be accepted if it:
+
+* Includes tests for new functionality.
+* Follows the guidelines in [Effective
+  Go](https://golang.org/doc/effective_go.html) and the [Go team's common code
+  review comments](https://github.com/golang/go/wiki/CodeReviewComments).
+* Has a [good commit message](https://chris.beams.io/posts/git-commit/):
+   * Separate subject from body with a blank line
+   * Limit the subject line to 50 characters
+   * Capitalize the subject line
+   * Do not end the subject line with a period
+   * Use the imperative mood in the subject line
+   * Wrap the body at 72 characters
+   * Use the body to explain _what_ and _why_ instead of _how_
+* Each commit must be signed by the author ([see below](#sign-your-work)).
+
+## License
+
+By contributing your code, you agree to license your contribution under the terms
+of the [Apache License](LICENSE).
+
+If you are adding a new file it should have a header like below.  The easiest
+way to add such header is to run `make fmt`.
+
+```
+// Copyright (c) 2017 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+```
+
+## Sign your work
+
+The sign-off is a simple line at the end of the explanation for the
+patch, which certifies that you wrote it or otherwise have the right to
+pass it on as an open-source patch.  The rules are pretty simple: if you
+can certify the below (from
+[developercertificate.org](http://developercertificate.org/)):
+
+```
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+660 York Street, Suite 102,
+San Francisco, CA 94110 USA
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
+```
+
+then you just add a line to every git commit message:
+
+    Signed-off-by: Joe Smith <joe@gmail.com>
+
+using your real name (sorry, no pseudonyms or anonymous contributions.)
+
+You can add the sign off when creating the git commit via `git commit -s`.
+
+If you want this to be automatic you can set up some aliases:
+
+```
+git config --add alias.amend "commit -s --amend"
+git config --add alias.c "commit -s"
+```

vendor/github.com/uber/jaeger-client-go/DCO

@@ -0,0 +1,37 @@
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+660 York Street, Suite 102,
+San Francisco, CA 94110 USA
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
+

vendor/github.com/uber/jaeger-client-go/Gopkg.lock

@@ -0,0 +1,164 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  branch = "master"
+  name = "github.com/beorn7/perks"
+  packages = ["quantile"]
+  revision = "3a771d992973f24aa725d07868b467d1ddfceafb"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/codahale/hdrhistogram"
+  packages = ["."]
+  revision = "3a0bb77429bd3a61596f5e8a3172445844342120"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/crossdock/crossdock-go"
+  packages = [
+    ".",
+    "assert",
+    "require"
+  ]
+  revision = "049aabb0122b03bc9bd30cab8f3f91fb60166361"
+
+[[projects]]
+  name = "github.com/davecgh/go-spew"
+  packages = ["spew"]
+  revision = "346938d642f2ec3594ed81d874461961cd0faa76"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "github.com/golang/protobuf"
+  packages = ["proto"]
+  revision = "925541529c1fa6821df4e44ce2723319eb2be768"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/matttproud/golang_protobuf_extensions"
+  packages = ["pbutil"]
+  revision = "3247c84500bff8d9fb6d579d800f20b3e091582c"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/opentracing/opentracing-go"
+  packages = [
+    ".",
+    "ext",
+    "log"
+  ]
+  revision = "1949ddbfd147afd4d964a9f00b24eb291e0e7c38"
+  version = "v1.0.2"
+
+[[projects]]
+  name = "github.com/pkg/errors"
+  packages = ["."]
+  revision = "645ef00459ed84a119197bfb8d8205042c6df63d"
+  version = "v0.8.0"
+
+[[projects]]
+  name = "github.com/pmezard/go-difflib"
+  packages = ["difflib"]
+  revision = "792786c7400a136282c1664665ae0a8db921c6c2"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/prometheus/client_golang"
+  packages = ["prometheus"]
+  revision = "c5b7fccd204277076155f10851dad72b76a49317"
+  version = "v0.8.0"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/client_model"
+  packages = ["go"]
+  revision = "99fa1f4be8e564e8a6b613da7fa6f46c9edafc6c"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/common"
+  packages = [
+    "expfmt",
+    "internal/bitbucket.org/ww/goautoneg",
+    "model"
+  ]
+  revision = "d811d2e9bf898806ecfb6ef6296774b13ffc314c"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/procfs"
+  packages = [
+    ".",
+    "internal/util",
+    "nfs",
+    "xfs"
+  ]
+  revision = "8b1c2da0d56deffdbb9e48d4414b4e674bd8083e"
+
+[[projects]]
+  name = "github.com/stretchr/testify"
+  packages = [
+    "assert",
+    "require",
+    "suite"
+  ]
+  revision = "12b6f73e6084dad08a7c6e575284b177ecafbc71"
+  version = "v1.2.1"
+
+[[projects]]
+  name = "github.com/uber-go/atomic"
+  packages = ["."]
+  revision = "8474b86a5a6f79c443ce4b2992817ff32cf208b8"
+  version = "v1.3.1"
+
+[[projects]]
+  name = "github.com/uber/jaeger-lib"
+  packages = [
+    "metrics",
+    "metrics/prometheus",
+    "metrics/testutils"
+  ]
+  revision = "4267858c0679cd4e47cefed8d7f70fd386cfb567"
+  version = "v1.4.0"
+
+[[projects]]
+  name = "go.uber.org/atomic"
+  packages = ["."]
+  revision = "54f72d32435d760d5604f17a82e2435b28dc4ba5"
+  version = "v1.3.0"
+
+[[projects]]
+  name = "go.uber.org/multierr"
+  packages = ["."]
+  revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "go.uber.org/zap"
+  packages = [
+    ".",
+    "buffer",
+    "internal/bufferpool",
+    "internal/color",
+    "internal/exit",
+    "zapcore"
+  ]
+  revision = "eeedf312bc6c57391d84767a4cd413f02a917974"
+  version = "v1.8.0"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/net"
+  packages = [
+    "context",
+    "context/ctxhttp"
+  ]
+  revision = "5f9ae10d9af5b1c89ae6904293b14b064d4ada23"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "f9dcfaf37a785c5dac1e20c29605eda29a83ba9c6f8842e92960dc94c8c4ff80"
+  solver-name = "gps-cdcl"
+  solver-version = 1

vendor/github.com/uber/jaeger-client-go/Gopkg.toml

@@ -0,0 +1,27 @@
+[[constraint]]
+  name = "github.com/crossdock/crossdock-go"
+  branch = "master"
+
+[[constraint]]
+  name = "github.com/opentracing/opentracing-go"
+  version = "^1"
+
+[[constraint]]
+  name = "github.com/prometheus/client_golang"
+  version = "0.8.0"
+
+[[constraint]]
+  name = "github.com/stretchr/testify"
+  version = "^1.1.3"
+
+[[constraint]]
+  name = "github.com/uber-go/atomic"
+  version = "^1"
+
+[[constraint]]
+  name = "github.com/uber/jaeger-lib"
+  version = "^1.3"
+
+[[constraint]]
+  name = "go.uber.org/zap"
+  version = "^1"

vendor/github.com/uber/jaeger-client-go/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
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+      the terms of any separate license agreement you may have executed
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+   6. Trademarks. This License does not grant permission to use the trade
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+      whether in tort (including negligence), contract, or otherwise,
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+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+       http://www.apache.org/licenses/LICENSE-2.0
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+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/uber/jaeger-client-go/Makefile

@@ -0,0 +1,117 @@
+PROJECT_ROOT=github.com/uber/jaeger-client-go
+PACKAGES := $(shell glide novendor | grep -v -e ./thrift-gen/... -e ./thrift/...)
+# all .go files that don't exist in hidden directories
+ALL_SRC := $(shell find . -name "*.go" | grep -v -e vendor -e thrift-gen -e ./thrift/ \
+        -e ".*/\..*" \
+        -e ".*/_.*" \
+        -e ".*/mocks.*")
+
+-include crossdock/rules.mk
+
+export GO15VENDOREXPERIMENT=1
+
+RACE=-race
+GOTEST=go test -v $(RACE)
+GOLINT=golint
+GOVET=go vet
+GOFMT=gofmt
+FMT_LOG=fmt.log
+LINT_LOG=lint.log
+
+THRIFT_VER=0.9.3
+THRIFT_IMG=thrift:$(THRIFT_VER)
+THRIFT=docker run -v "${PWD}:/data" $(THRIFT_IMG) thrift
+THRIFT_GO_ARGS=thrift_import="github.com/apache/thrift/lib/go/thrift"
+THRIFT_GEN_DIR=thrift-gen
+
+PASS=$(shell printf "\033[32mPASS\033[0m")
+FAIL=$(shell printf "\033[31mFAIL\033[0m")
+COLORIZE=sed ''/PASS/s//$(PASS)/'' | sed ''/FAIL/s//$(FAIL)/''
+
+.DEFAULT_GOAL := test-and-lint
+
+.PHONY: test-and-lint
+test-and-lint: test fmt lint
+
+.PHONY: test
+test:
+	bash -c "set -e; set -o pipefail; $(GOTEST) $(PACKAGES) | $(COLORIZE)"
+
+.PHONY: fmt
+fmt:
+	$(GOFMT) -e -s -l -w $(ALL_SRC)
+	./scripts/updateLicenses.sh
+
+.PHONY: lint
+lint:
+	$(GOVET) $(PACKAGES)
+	@cat /dev/null > $(LINT_LOG)
+	@$(foreach pkg, $(PACKAGES), $(GOLINT) $(pkg) | grep -v crossdock/thrift >> $(LINT_LOG) || true;)
+	@[ ! -s "$(LINT_LOG)" ] || (echo "Lint Failures" | cat - $(LINT_LOG) && false)
+	@$(GOFMT) -e -s -l $(ALL_SRC) > $(FMT_LOG)
+	./scripts/updateLicenses.sh >> $(FMT_LOG)
+	@[ ! -s "$(FMT_LOG)" ] || (echo "go fmt or license check failures, run 'make fmt'" | cat - $(FMT_LOG) && false)
+
+
+.PHONY: install
+install:
+	glide --version || go get github.com/Masterminds/glide
+ifeq ($(USE_DEP),true)
+	dep ensure
+else
+	glide install
+endif
+
+
+.PHONY: cover
+cover:
+	./scripts/cover.sh $(shell go list $(PACKAGES))
+	go tool cover -html=cover.out -o cover.html
+
+
+# This is not part of the regular test target because we don't want to slow it
+# down.
+.PHONY: test-examples
+test-examples:
+	make -C examples
+
+# TODO at the moment we're not generating tchan_*.go files
+thrift: idl-submodule thrift-image
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/$(THRIFT_GEN_DIR) /data/idl/thrift/agent.thrift
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/$(THRIFT_GEN_DIR) /data/idl/thrift/sampling.thrift
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/$(THRIFT_GEN_DIR) /data/idl/thrift/jaeger.thrift
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/$(THRIFT_GEN_DIR) /data/idl/thrift/zipkincore.thrift
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/$(THRIFT_GEN_DIR) /data/idl/thrift/baggage.thrift
+	$(THRIFT) -o /data --gen go:$(THRIFT_GO_ARGS) --out /data/crossdock/thrift/ /data/idl/thrift/crossdock/tracetest.thrift
+	sed -i '' 's|"zipkincore"|"$(PROJECT_ROOT)/thrift-gen/zipkincore"|g' $(THRIFT_GEN_DIR)/agent/*.go
+	sed -i '' 's|"jaeger"|"$(PROJECT_ROOT)/thrift-gen/jaeger"|g' $(THRIFT_GEN_DIR)/agent/*.go
+	sed -i '' 's|"github.com/apache/thrift/lib/go/thrift"|"github.com/uber/jaeger-client-go/thrift"|g' \
+		$(THRIFT_GEN_DIR)/*/*.go crossdock/thrift/tracetest/*.go
+	rm -rf thrift-gen/*/*-remote
+	rm -rf crossdock/thrift/*/*-remote
+	rm -rf thrift-gen/jaeger/collector.go
+
+idl-submodule:
+	git submodule init
+	git submodule update
+
+thrift-image:
+	$(THRIFT) -version
+
+.PHONY: install-dep-ci
+install-dep-ci:
+	- curl -L -s https://github.com/golang/dep/releases/download/v0.3.2/dep-linux-amd64 -o $$GOPATH/bin/dep
+	- chmod +x $$GOPATH/bin/dep
+
+.PHONY: install-ci
+install-ci: install-dep-ci install
+	go get github.com/wadey/gocovmerge
+	go get github.com/mattn/goveralls
+	go get golang.org/x/tools/cmd/cover
+	go get github.com/golang/lint/golint
+
+.PHONY: test-ci
+test-ci:
+	@./scripts/cover.sh $(shell go list $(PACKAGES))
+	make lint
+

vendor/github.com/uber/jaeger-client-go/README.md

@@ -0,0 +1,260 @@
+[![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov] [![OpenTracing 1.0 Enabled][ot-img]][ot-url]
+
+# Jaeger Bindings for Go OpenTracing API
+
+Instrumentation library that implements an
+[OpenTracing](http://opentracing.io) Tracer for Jaeger (https://jaegertracing.io).
+
+**IMPORTANT**: The library's import path is based on its original location under `github.com/uber`. Do not try to import it as `github.com/jaegertracing`, it will not compile. We might revisit this in the next major release.
+  * :white_check_mark: `import "github.com/uber/jaeger-client-go"`
+  * :x: `import "github.com/jaegertracing/jaeger-client-go"`
+
+## How to Contribute
+
+Please see [CONTRIBUTING.md](CONTRIBUTING.md).
+
+## Installation
+
+We recommended using a dependency manager like [glide](https://github.com/Masterminds/glide)
+and [semantic versioning](http://semver.org/) when including this library into an application.
+For example, Jaeger backend imports this library like this:
+
+```yaml
+- package: github.com/uber/jaeger-client-go
+  version: ^2.7.0
+```
+
+If you instead want to use the latest version in `master`, you can pull it via `go get`.
+Note that during `go get` you may see build errors due to incompatible dependencies, which is why
+we recommend using semantic versions for dependencies.  The error  may be fixed by running
+`make install` (it will install `glide` if you don't have it):
+
+```shell
+go get -u github.com/uber/jaeger-client-go/
+cd $GOPATH/src/github.com/uber/jaeger-client-go/
+git submodule update --init --recursive
+make install
+```
+
+## Initialization
+
+See tracer initialization examples in [godoc](https://godoc.org/github.com/uber/jaeger-client-go/config#pkg-examples)
+and [config/example_test.go](./config/example_test.go).
+
+### Environment variables
+
+The tracer can be initialized with values coming from environment variables. None of the env vars are required
+and all of them can be overriden via direct setting of the property on the configuration object.
+
+Property| Description
+--- | ---
+JAEGER_SERVICE_NAME | The service name
+JAEGER_AGENT_HOST | The hostname for communicating with agent via UDP
+JAEGER_AGENT_PORT | The port for communicating with agent via UDP
+JAEGER_REPORTER_LOG_SPANS | Whether the reporter should also log the spans
+JAEGER_REPORTER_MAX_QUEUE_SIZE | The reporter's maximum queue size
+JAEGER_REPORTER_FLUSH_INTERVAL | The reporter's flush interval (ms)
+JAEGER_SAMPLER_TYPE | The sampler type
+JAEGER_SAMPLER_PARAM | The sampler parameter (number)
+JAEGER_SAMPLER_MANAGER_HOST_PORT | The host name and port when using the remote controlled sampler
+JAEGER_SAMPLER_MAX_OPERATIONS | The maximum number of operations that the sampler will keep track of
+JAEGER_SAMPLER_REFRESH_INTERVAL | How often the remotely controlled sampler will poll jaeger-agent for the appropriate sampling strategy
+JAEGER_TAGS | A comma separated list of `name = value` tracer level tags, which get added to all reported spans. The value can also refer to an environment variable using the format `${envVarName:default}`, where the `:default` is optional, and identifies a value to be used if the environment variable cannot be found
+JAEGER_DISABLED | Whether the tracer is disabled or not. If true, the default `opentracing.NoopTracer` is used.
+JAEGER_RPC_METRICS | Whether to store RPC metrics
+
+### Closing the tracer via `io.Closer`
+
+The constructor function for Jaeger Tracer returns the tracer itself and an `io.Closer` instance.
+It is recommended to structure your `main()` so that it calls the `Close()` function on the closer
+before exiting, e.g.
+
+```go
+tracer, closer, err := cfg.NewTracer(...)
+defer closer.Close()
+```
+
+This is especially useful for command-line tools that enable tracing, as well as
+for the long-running apps that support graceful shutdown. For example, if your deployment
+system sends SIGTERM instead of killing the process and you trap that signal to do a graceful
+exit, then having `defer closer.Closer()` ensures that all buffered spans are flushed.
+
+### Metrics & Monitoring
+
+The tracer emits a number of different metrics, defined in
+[metrics.go](metrics.go). The monitoring backend is expected to support
+tag-based metric names, e.g. instead of `statsd`-style string names
+like `counters.my-service.jaeger.spans.started.sampled`, the metrics
+are defined by a short name and a collection of key/value tags, for
+example: `name:jaeger.traces, state:started, sampled:y`. See [metrics.go](./metrics.go)
+file for the full list and descriptions of emitted metrics.
+
+The monitoring backend is represented by the `metrics.Factory` interface from package
+[`"github.com/uber/jaeger-lib/metrics"`](https://github.com/jaegertracing/jaeger-lib/tree/master/metrics).  An implementation
+of that interface can be passed as an option to either the Configuration object or the Tracer
+constructor, for example:
+
+```go
+import (
+    "github.com/uber/jaeger-client-go/config"
+    "github.com/uber/jaeger-lib/metrics/prometheus"
+)
+
+    metricsFactory := prometheus.New()
+    tracer, closer, err := config.Configuration{
+        ServiceName: "your-service-name",
+    }.NewTracer(
+        config.Metrics(metricsFactory),
+    )
+```
+
+By default, a no-op `metrics.NullFactory` is used.
+
+### Logging
+
+The tracer can be configured with an optional logger, which will be
+used to log communication errors, or log spans if a logging reporter
+option is specified in the configuration. The logging API is abstracted
+by the [Logger](logger.go) interface. A logger instance implementing
+this interface can be set on the `Config` object before calling the
+`New` method.
+
+Besides the [zap](https://github.com/uber-go/zap) implementation
+bundled with this package there is also a [go-kit](https://github.com/go-kit/kit)
+one in the [jaeger-lib](https://github.com/jaegertracing/jaeger-lib) repository.
+
+## Instrumentation for Tracing
+
+Since this tracer is fully compliant with OpenTracing API 1.0,
+all code instrumentation should only use the API itself, as described
+in the [opentracing-go](https://github.com/opentracing/opentracing-go) documentation.
+
+## Features
+
+### Reporters
+
+A "reporter" is a component that receives the finished spans and reports
+them to somewhere. Under normal circumstances, the Tracer
+should use the default `RemoteReporter`, which sends the spans out of
+process via configurable "transport". For testing purposes, one can
+use an `InMemoryReporter` that accumulates spans in a buffer and
+allows to retrieve them for later verification. Also available are
+`NullReporter`, a no-op reporter that does nothing, a `LoggingReporter`
+which logs all finished spans using their `String()` method, and a
+`CompositeReporter` that can be used to combine more than one reporter
+into one, e.g. to attach a logging reporter to the main remote reporter.
+
+### Span Reporting Transports
+
+The remote reporter uses "transports" to actually send the spans out
+of process. Currently the supported transports include:
+  * [Jaeger Thrift](https://github.com/jaegertracing/jaeger-idl/blob/master/thrift/agent.thrift) over UDP or HTTP,
+  * [Zipkin Thrift](https://github.com/jaegertracing/jaeger-idl/blob/master/thrift/zipkincore.thrift) over HTTP.
+
+### Sampling
+
+The tracer does not record all spans, but only those that have the
+sampling bit set in the `flags`. When a new trace is started and a new
+unique ID is generated, a sampling decision is made whether this trace
+should be sampled. The sampling decision is propagated to all downstream
+calls via the `flags` field of the trace context. The following samplers
+are available:
+  1. `RemotelyControlledSampler` uses one of the other simpler samplers
+     and periodically updates it by polling an external server. This
+     allows dynamic control of the sampling strategies.
+  1. `ConstSampler` always makes the same sampling decision for all
+     trace IDs. it can be configured to either sample all traces, or
+     to sample none.
+  1. `ProbabilisticSampler` uses a fixed sampling rate as a probability
+     for a given trace to be sampled. The actual decision is made by
+     comparing the trace ID with a random number multiplied by the
+     sampling rate.
+  1. `RateLimitingSampler` can be used to allow only a certain fixed
+     number of traces to be sampled per second.
+
+### Baggage Injection
+
+The OpenTracing spec allows for [baggage][baggage], which are key value pairs that are added
+to the span context and propagated throughout the trace. An external process can inject baggage
+by setting the special HTTP Header `jaeger-baggage` on a request:
+
+```sh
+curl -H "jaeger-baggage: key1=value1, key2=value2" http://myhost.com
+```
+
+Baggage can also be programatically set inside your service:
+
+```go
+if span := opentracing.SpanFromContext(ctx); span != nil {
+    span.SetBaggageItem("key", "value")
+}
+```
+
+Another service downstream of that can retrieve the baggage in a similar way:
+
+```go
+if span := opentracing.SpanFromContext(ctx); span != nil {
+    val := span.BaggageItem("key")
+    println(val)
+}
+```
+
+### Debug Traces (Forced Sampling)
+
+#### Programmatically
+
+The OpenTracing API defines a `sampling.priority` standard tag that
+can be used to affect the sampling of a span and its children:
+
+```go
+import (
+    "github.com/opentracing/opentracing-go"
+    "github.com/opentracing/opentracing-go/ext"
+)
+
+span := opentracing.SpanFromContext(ctx)
+ext.SamplingPriority.Set(span, 1)    
+```
+
+#### Via HTTP Headers
+
+Jaeger Tracer also understands a special HTTP Header `jaeger-debug-id`,
+which can be set in the incoming request, e.g.
+
+```sh
+curl -H "jaeger-debug-id: some-correlation-id" http://myhost.com
+```
+
+When Jaeger sees this header in the request that otherwise has no
+tracing context, it ensures that the new trace started for this
+request will be sampled in the "debug" mode (meaning it should survive
+all downsampling that might happen in the collection pipeline), and the
+root span will have a tag as if this statement was executed:
+
+```go
+span.SetTag("jaeger-debug-id", "some-correlation-id")
+```
+
+This allows using Jaeger UI to find the trace by this tag.
+
+### Zipkin HTTP B3 compatible header propagation
+
+Jaeger Tracer supports Zipkin B3 Propagation HTTP headers, which are used
+by a lot of Zipkin tracers. This means that you can use Jaeger in conjunction with e.g. [these OpenZipkin tracers](https://github.com/openzipkin).
+
+However it is not the default propagation format, see [here](zipkin/README.md#NewZipkinB3HTTPHeaderPropagator) how to set it up.
+
+## License
+
+[Apache 2.0 License](LICENSE).
+
+
+[doc-img]: https://godoc.org/github.com/uber/jaeger-client-go?status.svg
+[doc]: https://godoc.org/github.com/uber/jaeger-client-go
+[ci-img]: https://travis-ci.org/jaegertracing/jaeger-client-go.svg?branch=master
+[ci]: https://travis-ci.org/jaegertracing/jaeger-client-go
+[cov-img]: https://codecov.io/gh/jaegertracing/jaeger-client-go/branch/master/graph/badge.svg
+[cov]: https://codecov.io/gh/jaegertracing/jaeger-client-go
+[ot-img]: https://img.shields.io/badge/OpenTracing--1.0-enabled-blue.svg
+[ot-url]: http://opentracing.io
+[baggage]: https://github.com/opentracing/specification/blob/master/specification.md#set-a-baggage-item

vendor/github.com/uber/jaeger-client-go/RELEASE.md

@@ -0,0 +1,11 @@
+# Release Process
+
+1. Create a PR "Preparing for release X.Y.Z" against master branch
+    * Alter CHANGELOG.md from `<placeholder_version> (unreleased)` to `<X.Y.Z> (YYYY-MM-DD)`
+    * Update `JaegerClientVersion` in constants.go to `Go-X.Y.Z`
+2. Create a release "Release X.Y.Z" on Github
+    * Create Tag `vX.Y.Z`
+    * Copy CHANGELOG.md into the release notes
+3. Create a PR "Back to development" against master branch
+    * Add `<next_version> (unreleased)` to CHANGELOG.md
+    * Update `JaegerClientVersion` in constants.go to `Go-<next_version>dev`

vendor/github.com/uber/jaeger-client-go/baggage_setter.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"github.com/opentracing/opentracing-go/log"
+
+	"github.com/uber/jaeger-client-go/internal/baggage"
+)
+
+// baggageSetter is an actor that can set a baggage value on a Span given certain
+// restrictions (eg. maxValueLength).
+type baggageSetter struct {
+	restrictionManager baggage.RestrictionManager
+	metrics            *Metrics
+}
+
+func newBaggageSetter(restrictionManager baggage.RestrictionManager, metrics *Metrics) *baggageSetter {
+	return &baggageSetter{
+		restrictionManager: restrictionManager,
+		metrics:            metrics,
+	}
+}
+
+// (NB) span should hold the lock before making this call
+func (s *baggageSetter) setBaggage(span *Span, key, value string) {
+	var truncated bool
+	var prevItem string
+	restriction := s.restrictionManager.GetRestriction(span.serviceName(), key)
+	if !restriction.KeyAllowed() {
+		s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
+		s.metrics.BaggageUpdateFailure.Inc(1)
+		return
+	}
+	if len(value) > restriction.MaxValueLength() {
+		truncated = true
+		value = value[:restriction.MaxValueLength()]
+		s.metrics.BaggageTruncate.Inc(1)
+	}
+	prevItem = span.context.baggage[key]
+	s.logFields(span, key, value, prevItem, truncated, restriction.KeyAllowed())
+	span.context = span.context.WithBaggageItem(key, value)
+	s.metrics.BaggageUpdateSuccess.Inc(1)
+}
+
+func (s *baggageSetter) logFields(span *Span, key, value, prevItem string, truncated, valid bool) {
+	if !span.context.IsSampled() {
+		return
+	}
+	fields := []log.Field{
+		log.String("event", "baggage"),
+		log.String("key", key),
+		log.String("value", value),
+	}
+	if prevItem != "" {
+		fields = append(fields, log.String("override", "true"))
+	}
+	if truncated {
+		fields = append(fields, log.String("truncated", "true"))
+	}
+	if !valid {
+		fields = append(fields, log.String("invalid", "true"))
+	}
+	span.logFieldsNoLocking(fields...)
+}

vendor/github.com/uber/jaeger-client-go/config/config.go

@@ -0,0 +1,373 @@
+// Copyright (c) 2017-2018 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	"github.com/opentracing/opentracing-go"
+
+	"github.com/uber/jaeger-client-go"
+	"github.com/uber/jaeger-client-go/internal/baggage/remote"
+	throttler "github.com/uber/jaeger-client-go/internal/throttler/remote"
+	"github.com/uber/jaeger-client-go/rpcmetrics"
+)
+
+const defaultSamplingProbability = 0.001
+
+// Configuration configures and creates Jaeger Tracer
+type Configuration struct {
+	// ServiceName specifies the service name to use on the tracer.
+	// Can be provided via environment variable named JAEGER_SERVICE_NAME
+	ServiceName string `yaml:"serviceName"`
+
+	// Disabled can be provided via environment variable named JAEGER_DISABLED
+	Disabled bool `yaml:"disabled"`
+
+	// RPCMetrics can be provided via environment variable named JAEGER_RPC_METRICS
+	RPCMetrics bool `yaml:"rpc_metrics"`
+
+	// Tags can be provided via environment variable named JAEGER_TAGS
+	Tags []opentracing.Tag `yaml:"tags"`
+
+	Sampler             *SamplerConfig             `yaml:"sampler"`
+	Reporter            *ReporterConfig            `yaml:"reporter"`
+	Headers             *jaeger.HeadersConfig      `yaml:"headers"`
+	BaggageRestrictions *BaggageRestrictionsConfig `yaml:"baggage_restrictions"`
+	Throttler           *ThrottlerConfig           `yaml:"throttler"`
+}
+
+// SamplerConfig allows initializing a non-default sampler.  All fields are optional.
+type SamplerConfig struct {
+	// Type specifies the type of the sampler: const, probabilistic, rateLimiting, or remote
+	// Can be set by exporting an environment variable named JAEGER_SAMPLER_TYPE
+	Type string `yaml:"type"`
+
+	// Param is a value passed to the sampler.
+	// Valid values for Param field are:
+	// - for "const" sampler, 0 or 1 for always false/true respectively
+	// - for "probabilistic" sampler, a probability between 0 and 1
+	// - for "rateLimiting" sampler, the number of spans per second
+	// - for "remote" sampler, param is the same as for "probabilistic"
+	//   and indicates the initial sampling rate before the actual one
+	//   is received from the mothership.
+	// Can be set by exporting an environment variable named JAEGER_SAMPLER_PARAM
+	Param float64 `yaml:"param"`
+
+	// SamplingServerURL is the address of jaeger-agent's HTTP sampling server
+	// Can be set by exporting an environment variable named JAEGER_SAMPLER_MANAGER_HOST_PORT
+	SamplingServerURL string `yaml:"samplingServerURL"`
+
+	// MaxOperations is the maximum number of operations that the sampler
+	// will keep track of. If an operation is not tracked, a default probabilistic
+	// sampler will be used rather than the per operation specific sampler.
+	// Can be set by exporting an environment variable named JAEGER_SAMPLER_MAX_OPERATIONS
+	MaxOperations int `yaml:"maxOperations"`
+
+	// SamplingRefreshInterval controls how often the remotely controlled sampler will poll
+	// jaeger-agent for the appropriate sampling strategy.
+	// Can be set by exporting an environment variable named JAEGER_SAMPLER_REFRESH_INTERVAL
+	SamplingRefreshInterval time.Duration `yaml:"samplingRefreshInterval"`
+}
+
+// ReporterConfig configures the reporter. All fields are optional.
+type ReporterConfig struct {
+	// QueueSize controls how many spans the reporter can keep in memory before it starts dropping
+	// new spans. The queue is continuously drained by a background go-routine, as fast as spans
+	// can be sent out of process.
+	// Can be set by exporting an environment variable named JAEGER_REPORTER_MAX_QUEUE_SIZE
+	QueueSize int `yaml:"queueSize"`
+
+	// BufferFlushInterval controls how often the buffer is force-flushed, even if it's not full.
+	// It is generally not useful, as it only matters for very low traffic services.
+	// Can be set by exporting an environment variable named JAEGER_REPORTER_FLUSH_INTERVAL
+	BufferFlushInterval time.Duration
+
+	// LogSpans, when true, enables LoggingReporter that runs in parallel with the main reporter
+	// and logs all submitted spans. Main Configuration.Logger must be initialized in the code
+	// for this option to have any effect.
+	// Can be set by exporting an environment variable named JAEGER_REPORTER_LOG_SPANS
+	LogSpans bool `yaml:"logSpans"`
+
+	// LocalAgentHostPort instructs reporter to send spans to jaeger-agent at this address
+	// Can be set by exporting an environment variable named JAEGER_AGENT_HOST / JAEGER_AGENT_PORT
+	LocalAgentHostPort string `yaml:"localAgentHostPort"`
+}
+
+// BaggageRestrictionsConfig configures the baggage restrictions manager which can be used to whitelist
+// certain baggage keys. All fields are optional.
+type BaggageRestrictionsConfig struct {
+	// DenyBaggageOnInitializationFailure controls the startup failure mode of the baggage restriction
+	// manager. If true, the manager will not allow any baggage to be written until baggage restrictions have
+	// been retrieved from jaeger-agent. If false, the manager wil allow any baggage to be written until baggage
+	// restrictions have been retrieved from jaeger-agent.
+	DenyBaggageOnInitializationFailure bool `yaml:"denyBaggageOnInitializationFailure"`
+
+	// HostPort is the hostPort of jaeger-agent's baggage restrictions server
+	HostPort string `yaml:"hostPort"`
+
+	// RefreshInterval controls how often the baggage restriction manager will poll
+	// jaeger-agent for the most recent baggage restrictions.
+	RefreshInterval time.Duration `yaml:"refreshInterval"`
+}
+
+// ThrottlerConfig configures the throttler which can be used to throttle the
+// rate at which the client may send debug requests.
+type ThrottlerConfig struct {
+	// HostPort of jaeger-agent's credit server.
+	HostPort string `yaml:"hostPort"`
+
+	// RefreshInterval controls how often the throttler will poll jaeger-agent
+	// for more throttling credits.
+	RefreshInterval time.Duration `yaml:"refreshInterval"`
+
+	// SynchronousInitialization determines whether or not the throttler should
+	// synchronously fetch credits from the agent when an operation is seen for
+	// the first time. This should be set to true if the client will be used by
+	// a short lived service that needs to ensure that credits are fetched
+	// upfront such that sampling or throttling occurs.
+	SynchronousInitialization bool `yaml:"synchronousInitialization"`
+}
+
+type nullCloser struct{}
+
+func (*nullCloser) Close() error { return nil }
+
+// New creates a new Jaeger Tracer, and a closer func that can be used to flush buffers
+// before shutdown.
+//
+// Deprecated: use NewTracer() function
+func (c Configuration) New(
+	serviceName string,
+	options ...Option,
+) (opentracing.Tracer, io.Closer, error) {
+	if serviceName != "" {
+		c.ServiceName = serviceName
+	}
+
+	return c.NewTracer(options...)
+}
+
+// NewTracer returns a new tracer based on the current configuration, using the given options,
+// and a closer func that can be used to flush buffers before shutdown.
+func (c Configuration) NewTracer(options ...Option) (opentracing.Tracer, io.Closer, error) {
+	if c.ServiceName == "" {
+		return nil, nil, errors.New("no service name provided")
+	}
+
+	if c.Disabled {
+		return &opentracing.NoopTracer{}, &nullCloser{}, nil
+	}
+	opts := applyOptions(options...)
+	tracerMetrics := jaeger.NewMetrics(opts.metrics, nil)
+	if c.RPCMetrics {
+		Observer(
+			rpcmetrics.NewObserver(
+				opts.metrics.Namespace("jaeger-rpc", map[string]string{"component": "jaeger"}),
+				rpcmetrics.DefaultNameNormalizer,
+			),
+		)(&opts) // adds to c.observers
+	}
+	if c.Sampler == nil {
+		c.Sampler = &SamplerConfig{
+			Type:  jaeger.SamplerTypeRemote,
+			Param: defaultSamplingProbability,
+		}
+	}
+	if c.Reporter == nil {
+		c.Reporter = &ReporterConfig{}
+	}
+
+	sampler := opts.sampler
+	if sampler == nil {
+		s, err := c.Sampler.NewSampler(c.ServiceName, tracerMetrics)
+		if err != nil {
+			return nil, nil, err
+		}
+		sampler = s
+	}
+
+	reporter := opts.reporter
+	if reporter == nil {
+		r, err := c.Reporter.NewReporter(c.ServiceName, tracerMetrics, opts.logger)
+		if err != nil {
+			return nil, nil, err
+		}
+		reporter = r
+	}
+
+	tracerOptions := []jaeger.TracerOption{
+		jaeger.TracerOptions.Metrics(tracerMetrics),
+		jaeger.TracerOptions.Logger(opts.logger),
+		jaeger.TracerOptions.CustomHeaderKeys(c.Headers),
+		jaeger.TracerOptions.Gen128Bit(opts.gen128Bit),
+		jaeger.TracerOptions.ZipkinSharedRPCSpan(opts.zipkinSharedRPCSpan),
+		jaeger.TracerOptions.MaxTagValueLength(opts.maxTagValueLength),
+	}
+
+	for _, tag := range opts.tags {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Tag(tag.Key, tag.Value))
+	}
+
+	for _, tag := range c.Tags {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Tag(tag.Key, tag.Value))
+	}
+
+	for _, obs := range opts.observers {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Observer(obs))
+	}
+
+	for _, cobs := range opts.contribObservers {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.ContribObserver(cobs))
+	}
+
+	for format, injector := range opts.injectors {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Injector(format, injector))
+	}
+
+	for format, extractor := range opts.extractors {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Extractor(format, extractor))
+	}
+
+	if c.BaggageRestrictions != nil {
+		mgr := remote.NewRestrictionManager(
+			c.ServiceName,
+			remote.Options.Metrics(tracerMetrics),
+			remote.Options.Logger(opts.logger),
+			remote.Options.HostPort(c.BaggageRestrictions.HostPort),
+			remote.Options.RefreshInterval(c.BaggageRestrictions.RefreshInterval),
+			remote.Options.DenyBaggageOnInitializationFailure(
+				c.BaggageRestrictions.DenyBaggageOnInitializationFailure,
+			),
+		)
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.BaggageRestrictionManager(mgr))
+	}
+
+	if c.Throttler != nil {
+		debugThrottler := throttler.NewThrottler(
+			c.ServiceName,
+			throttler.Options.Metrics(tracerMetrics),
+			throttler.Options.Logger(opts.logger),
+			throttler.Options.HostPort(c.Throttler.HostPort),
+			throttler.Options.RefreshInterval(c.Throttler.RefreshInterval),
+			throttler.Options.SynchronousInitialization(
+				c.Throttler.SynchronousInitialization,
+			),
+		)
+
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.DebugThrottler(debugThrottler))
+	}
+
+	tracer, closer := jaeger.NewTracer(
+		c.ServiceName,
+		sampler,
+		reporter,
+		tracerOptions...,
+	)
+
+	return tracer, closer, nil
+}
+
+// InitGlobalTracer creates a new Jaeger Tracer, and sets it as global OpenTracing Tracer.
+// It returns a closer func that can be used to flush buffers before shutdown.
+func (c Configuration) InitGlobalTracer(
+	serviceName string,
+	options ...Option,
+) (io.Closer, error) {
+	if c.Disabled {
+		return &nullCloser{}, nil
+	}
+	tracer, closer, err := c.New(serviceName, options...)
+	if err != nil {
+		return nil, err
+	}
+	opentracing.SetGlobalTracer(tracer)
+	return closer, nil
+}
+
+// NewSampler creates a new sampler based on the configuration
+func (sc *SamplerConfig) NewSampler(
+	serviceName string,
+	metrics *jaeger.Metrics,
+) (jaeger.Sampler, error) {
+	samplerType := strings.ToLower(sc.Type)
+	if samplerType == jaeger.SamplerTypeConst {
+		return jaeger.NewConstSampler(sc.Param != 0), nil
+	}
+	if samplerType == jaeger.SamplerTypeProbabilistic {
+		if sc.Param >= 0 && sc.Param <= 1.0 {
+			return jaeger.NewProbabilisticSampler(sc.Param)
+		}
+		return nil, fmt.Errorf(
+			"Invalid Param for probabilistic sampler: %v. Expecting value between 0 and 1",
+			sc.Param,
+		)
+	}
+	if samplerType == jaeger.SamplerTypeRateLimiting {
+		return jaeger.NewRateLimitingSampler(sc.Param), nil
+	}
+	if samplerType == jaeger.SamplerTypeRemote || sc.Type == "" {
+		sc2 := *sc
+		sc2.Type = jaeger.SamplerTypeProbabilistic
+		initSampler, err := sc2.NewSampler(serviceName, nil)
+		if err != nil {
+			return nil, err
+		}
+		options := []jaeger.SamplerOption{
+			jaeger.SamplerOptions.Metrics(metrics),
+			jaeger.SamplerOptions.InitialSampler(initSampler),
+			jaeger.SamplerOptions.SamplingServerURL(sc.SamplingServerURL),
+		}
+		if sc.MaxOperations != 0 {
+			options = append(options, jaeger.SamplerOptions.MaxOperations(sc.MaxOperations))
+		}
+		if sc.SamplingRefreshInterval != 0 {
+			options = append(options, jaeger.SamplerOptions.SamplingRefreshInterval(sc.SamplingRefreshInterval))
+		}
+		return jaeger.NewRemotelyControlledSampler(serviceName, options...), nil
+	}
+	return nil, fmt.Errorf("Unknown sampler type %v", sc.Type)
+}
+
+// NewReporter instantiates a new reporter that submits spans to tcollector
+func (rc *ReporterConfig) NewReporter(
+	serviceName string,
+	metrics *jaeger.Metrics,
+	logger jaeger.Logger,
+) (jaeger.Reporter, error) {
+	sender, err := rc.newTransport()
+	if err != nil {
+		return nil, err
+	}
+	reporter := jaeger.NewRemoteReporter(
+		sender,
+		jaeger.ReporterOptions.QueueSize(rc.QueueSize),
+		jaeger.ReporterOptions.BufferFlushInterval(rc.BufferFlushInterval),
+		jaeger.ReporterOptions.Logger(logger),
+		jaeger.ReporterOptions.Metrics(metrics))
+	if rc.LogSpans && logger != nil {
+		logger.Infof("Initializing logging reporter\n")
+		reporter = jaeger.NewCompositeReporter(jaeger.NewLoggingReporter(logger), reporter)
+	}
+	return reporter, err
+}
+
+func (rc *ReporterConfig) newTransport() (jaeger.Transport, error) {
+	return jaeger.NewUDPTransport(rc.LocalAgentHostPort, 0)
+}

vendor/github.com/uber/jaeger-client-go/config/config_env.go

@@ -0,0 +1,205 @@
+// Copyright (c) 2018 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/pkg/errors"
+
+	"github.com/uber/jaeger-client-go"
+)
+
+const (
+	// environment variable names
+	envServiceName            = "JAEGER_SERVICE_NAME"
+	envDisabled               = "JAEGER_DISABLED"
+	envRPCMetrics             = "JAEGER_RPC_METRICS"
+	envTags                   = "JAEGER_TAGS"
+	envSamplerType            = "JAEGER_SAMPLER_TYPE"
+	envSamplerParam           = "JAEGER_SAMPLER_PARAM"
+	envSamplerManagerHostPort = "JAEGER_SAMPLER_MANAGER_HOST_PORT"
+	envSamplerMaxOperations   = "JAEGER_SAMPLER_MAX_OPERATIONS"
+	envSamplerRefreshInterval = "JAEGER_SAMPLER_REFRESH_INTERVAL"
+	envReporterMaxQueueSize   = "JAEGER_REPORTER_MAX_QUEUE_SIZE"
+	envReporterFlushInterval  = "JAEGER_REPORTER_FLUSH_INTERVAL"
+	envReporterLogSpans       = "JAEGER_REPORTER_LOG_SPANS"
+	envAgentHost              = "JAEGER_AGENT_HOST"
+	envAgentPort              = "JAEGER_AGENT_PORT"
+)
+
+// FromEnv uses environment variables to set the tracer's Configuration
+func FromEnv() (*Configuration, error) {
+	c := &Configuration{}
+
+	if e := os.Getenv(envServiceName); e != "" {
+		c.ServiceName = e
+	}
+
+	if e := os.Getenv(envRPCMetrics); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			c.RPCMetrics = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envRPCMetrics, e)
+		}
+	}
+
+	if e := os.Getenv(envDisabled); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			c.Disabled = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envDisabled, e)
+		}
+	}
+
+	if e := os.Getenv(envTags); e != "" {
+		c.Tags = parseTags(e)
+	}
+
+	if s, err := samplerConfigFromEnv(); err == nil {
+		c.Sampler = s
+	} else {
+		return nil, errors.Wrap(err, "cannot obtain sampler config from env")
+	}
+
+	if r, err := reporterConfigFromEnv(); err == nil {
+		c.Reporter = r
+	} else {
+		return nil, errors.Wrap(err, "cannot obtain reporter config from env")
+	}
+
+	return c, nil
+}
+
+// samplerConfigFromEnv creates a new SamplerConfig based on the environment variables
+func samplerConfigFromEnv() (*SamplerConfig, error) {
+	sc := &SamplerConfig{}
+
+	if e := os.Getenv(envSamplerType); e != "" {
+		sc.Type = e
+	}
+
+	if e := os.Getenv(envSamplerParam); e != "" {
+		if value, err := strconv.ParseFloat(e, 64); err == nil {
+			sc.Param = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerParam, e)
+		}
+	}
+
+	if e := os.Getenv(envSamplerManagerHostPort); e != "" {
+		sc.SamplingServerURL = e
+	}
+
+	if e := os.Getenv(envSamplerMaxOperations); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			sc.MaxOperations = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerMaxOperations, e)
+		}
+	}
+
+	if e := os.Getenv(envSamplerRefreshInterval); e != "" {
+		if value, err := time.ParseDuration(e); err == nil {
+			sc.SamplingRefreshInterval = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envSamplerRefreshInterval, e)
+		}
+	}
+
+	return sc, nil
+}
+
+// reporterConfigFromEnv creates a new ReporterConfig based on the environment variables
+func reporterConfigFromEnv() (*ReporterConfig, error) {
+	rc := &ReporterConfig{}
+
+	if e := os.Getenv(envReporterMaxQueueSize); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			rc.QueueSize = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterMaxQueueSize, e)
+		}
+	}
+
+	if e := os.Getenv(envReporterFlushInterval); e != "" {
+		if value, err := time.ParseDuration(e); err == nil {
+			rc.BufferFlushInterval = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterFlushInterval, e)
+		}
+	}
+
+	if e := os.Getenv(envReporterLogSpans); e != "" {
+		if value, err := strconv.ParseBool(e); err == nil {
+			rc.LogSpans = value
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envReporterLogSpans, e)
+		}
+	}
+
+	host := jaeger.DefaultUDPSpanServerHost
+	if e := os.Getenv(envAgentHost); e != "" {
+		host = e
+	}
+
+	port := jaeger.DefaultUDPSpanServerPort
+	if e := os.Getenv(envAgentPort); e != "" {
+		if value, err := strconv.ParseInt(e, 10, 0); err == nil {
+			port = int(value)
+		} else {
+			return nil, errors.Wrapf(err, "cannot parse env var %s=%s", envAgentPort, e)
+		}
+	}
+
+	// the side effect of this is that we are building the default value, even if none of the env vars
+	// were not explicitly passed
+	rc.LocalAgentHostPort = fmt.Sprintf("%s:%d", host, port)
+
+	return rc, nil
+}
+
+// parseTags parses the given string into a collection of Tags.
+// Spec for this value:
+// - comma separated list of key=value
+// - value can be specified using the notation ${envVar:defaultValue}, where `envVar`
+// is an environment variable and `defaultValue` is the value to use in case the env var is not set
+func parseTags(sTags string) []opentracing.Tag {
+	pairs := strings.Split(sTags, ",")
+	tags := make([]opentracing.Tag, 0)
+	for _, p := range pairs {
+		kv := strings.SplitN(p, "=", 2)
+		k, v := strings.TrimSpace(kv[0]), strings.TrimSpace(kv[1])
+
+		if strings.HasPrefix(v, "${") && strings.HasSuffix(v, "}") {
+			ed := strings.SplitN(v[2:len(v)-1], ":", 2)
+			e, d := ed[0], ed[1]
+			v = os.Getenv(e)
+			if v == "" && d != "" {
+				v = d
+			}
+		}
+
+		tag := opentracing.Tag{Key: k, Value: v}
+		tags = append(tags, tag)
+	}
+
+	return tags
+}

vendor/github.com/uber/jaeger-client-go/config/options.go

@@ -0,0 +1,148 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/uber/jaeger-lib/metrics"
+
+	"github.com/uber/jaeger-client-go"
+)
+
+// Option is a function that sets some option on the client.
+type Option func(c *Options)
+
+// Options control behavior of the client.
+type Options struct {
+	metrics             metrics.Factory
+	logger              jaeger.Logger
+	reporter            jaeger.Reporter
+	sampler             jaeger.Sampler
+	contribObservers    []jaeger.ContribObserver
+	observers           []jaeger.Observer
+	gen128Bit           bool
+	zipkinSharedRPCSpan bool
+	maxTagValueLength   int
+	tags                []opentracing.Tag
+	injectors           map[interface{}]jaeger.Injector
+	extractors          map[interface{}]jaeger.Extractor
+}
+
+// Metrics creates an Option that initializes Metrics in the tracer,
+// which is used to emit statistics about spans.
+func Metrics(factory metrics.Factory) Option {
+	return func(c *Options) {
+		c.metrics = factory
+	}
+}
+
+// Logger can be provided to log Reporter errors, as well as to log spans
+// if Reporter.LogSpans is set to true.
+func Logger(logger jaeger.Logger) Option {
+	return func(c *Options) {
+		c.logger = logger
+	}
+}
+
+// Reporter can be provided explicitly to override the configuration.
+// Useful for testing, e.g. by passing InMemoryReporter.
+func Reporter(reporter jaeger.Reporter) Option {
+	return func(c *Options) {
+		c.reporter = reporter
+	}
+}
+
+// Sampler can be provided explicitly to override the configuration.
+func Sampler(sampler jaeger.Sampler) Option {
+	return func(c *Options) {
+		c.sampler = sampler
+	}
+}
+
+// Observer can be registered with the Tracer to receive notifications about new Spans.
+func Observer(observer jaeger.Observer) Option {
+	return func(c *Options) {
+		c.observers = append(c.observers, observer)
+	}
+}
+
+// ContribObserver can be registered with the Tracer to recieve notifications
+// about new spans.
+func ContribObserver(observer jaeger.ContribObserver) Option {
+	return func(c *Options) {
+		c.contribObservers = append(c.contribObservers, observer)
+	}
+}
+
+// Gen128Bit specifies whether to generate 128bit trace IDs.
+func Gen128Bit(gen128Bit bool) Option {
+	return func(c *Options) {
+		c.gen128Bit = gen128Bit
+	}
+}
+
+// ZipkinSharedRPCSpan creates an option that enables sharing span ID between client
+// and server spans a la zipkin. If false, client and server spans will be assigned
+// different IDs.
+func ZipkinSharedRPCSpan(zipkinSharedRPCSpan bool) Option {
+	return func(c *Options) {
+		c.zipkinSharedRPCSpan = zipkinSharedRPCSpan
+	}
+}
+
+// MaxTagValueLength can be provided to override the default max tag value length.
+func MaxTagValueLength(maxTagValueLength int) Option {
+	return func(c *Options) {
+		c.maxTagValueLength = maxTagValueLength
+	}
+}
+
+// Tag creates an option that adds a tracer-level tag.
+func Tag(key string, value interface{}) Option {
+	return func(c *Options) {
+		c.tags = append(c.tags, opentracing.Tag{Key: key, Value: value})
+	}
+}
+
+// Injector registers an Injector with the given format.
+func Injector(format interface{}, injector jaeger.Injector) Option {
+	return func(c *Options) {
+		c.injectors[format] = injector
+	}
+}
+
+// Extractor registers an Extractor with the given format.
+func Extractor(format interface{}, extractor jaeger.Extractor) Option {
+	return func(c *Options) {
+		c.extractors[format] = extractor
+	}
+}
+
+func applyOptions(options ...Option) Options {
+	opts := Options{
+		injectors:  make(map[interface{}]jaeger.Injector),
+		extractors: make(map[interface{}]jaeger.Extractor),
+	}
+	for _, option := range options {
+		option(&opts)
+	}
+	if opts.metrics == nil {
+		opts.metrics = metrics.NullFactory
+	}
+	if opts.logger == nil {
+		opts.logger = jaeger.NullLogger
+	}
+	return opts
+}

vendor/github.com/uber/jaeger-client-go/constants.go

@@ -0,0 +1,88 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+const (
+	// JaegerClientVersion is the version of the client library reported as Span tag.
+	JaegerClientVersion = "Go-2.15.0-dev"
+
+	// JaegerClientVersionTagKey is the name of the tag used to report client version.
+	JaegerClientVersionTagKey = "jaeger.version"
+
+	// JaegerDebugHeader is the name of HTTP header or a TextMap carrier key which,
+	// if found in the carrier, forces the trace to be sampled as "debug" trace.
+	// The value of the header is recorded as the tag on the root span, so that the
+	// trace can be found in the UI using this value as a correlation ID.
+	JaegerDebugHeader = "jaeger-debug-id"
+
+	// JaegerBaggageHeader is the name of the HTTP header that is used to submit baggage.
+	// It differs from TraceBaggageHeaderPrefix in that it can be used only in cases where
+	// a root span does not exist.
+	JaegerBaggageHeader = "jaeger-baggage"
+
+	// TracerHostnameTagKey used to report host name of the process.
+	TracerHostnameTagKey = "hostname"
+
+	// TracerIPTagKey used to report ip of the process.
+	TracerIPTagKey = "ip"
+
+	// TracerUUIDTagKey used to report UUID of the client process.
+	TracerUUIDTagKey = "client-uuid"
+
+	// SamplerTypeTagKey reports which sampler was used on the root span.
+	SamplerTypeTagKey = "sampler.type"
+
+	// SamplerParamTagKey reports the parameter of the sampler, like sampling probability.
+	SamplerParamTagKey = "sampler.param"
+
+	// TraceContextHeaderName is the http header name used to propagate tracing context.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceContextHeaderName = "uber-trace-id"
+
+	// TracerStateHeaderName is deprecated.
+	// Deprecated: use TraceContextHeaderName
+	TracerStateHeaderName = TraceContextHeaderName
+
+	// TraceBaggageHeaderPrefix is the prefix for http headers used to propagate baggage.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceBaggageHeaderPrefix = "uberctx-"
+
+	// SamplerTypeConst is the type of sampler that always makes the same decision.
+	SamplerTypeConst = "const"
+
+	// SamplerTypeRemote is the type of sampler that polls Jaeger agent for sampling strategy.
+	SamplerTypeRemote = "remote"
+
+	// SamplerTypeProbabilistic is the type of sampler that samples traces
+	// with a certain fixed probability.
+	SamplerTypeProbabilistic = "probabilistic"
+
+	// SamplerTypeRateLimiting is the type of sampler that samples
+	// only up to a fixed number of traces per second.
+	SamplerTypeRateLimiting = "ratelimiting"
+
+	// SamplerTypeLowerBound is the type of sampler that samples
+	// at least a fixed number of traces per second.
+	SamplerTypeLowerBound = "lowerbound"
+
+	// DefaultUDPSpanServerHost is the default host to send the spans to, via UDP
+	DefaultUDPSpanServerHost = "localhost"
+
+	// DefaultUDPSpanServerPort is the default port to send the spans to, via UDP
+	DefaultUDPSpanServerPort = 6831
+
+	// DefaultMaxTagValueLength is the default max length of byte array or string allowed in the tag value.
+	DefaultMaxTagValueLength = 256
+)

vendor/github.com/uber/jaeger-client-go/context.go

@@ -0,0 +1,258 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	flagSampled = byte(1)
+	flagDebug   = byte(2)
+)
+
+var (
+	errEmptyTracerStateString     = errors.New("Cannot convert empty string to tracer state")
+	errMalformedTracerStateString = errors.New("String does not match tracer state format")
+
+	emptyContext = SpanContext{}
+)
+
+// TraceID represents unique 128bit identifier of a trace
+type TraceID struct {
+	High, Low uint64
+}
+
+// SpanID represents unique 64bit identifier of a span
+type SpanID uint64
+
+// SpanContext represents propagated span identity and state
+type SpanContext struct {
+	// traceID represents globally unique ID of the trace.
+	// Usually generated as a random number.
+	traceID TraceID
+
+	// spanID represents span ID that must be unique within its trace,
+	// but does not have to be globally unique.
+	spanID SpanID
+
+	// parentID refers to the ID of the parent span.
+	// Should be 0 if the current span is a root span.
+	parentID SpanID
+
+	// flags is a bitmap containing such bits as 'sampled' and 'debug'.
+	flags byte
+
+	// Distributed Context baggage. The is a snapshot in time.
+	baggage map[string]string
+
+	// debugID can be set to some correlation ID when the context is being
+	// extracted from a TextMap carrier.
+	//
+	// See JaegerDebugHeader in constants.go
+	debugID string
+}
+
+// ForeachBaggageItem implements ForeachBaggageItem() of opentracing.SpanContext
+func (c SpanContext) ForeachBaggageItem(handler func(k, v string) bool) {
+	for k, v := range c.baggage {
+		if !handler(k, v) {
+			break
+		}
+	}
+}
+
+// IsSampled returns whether this trace was chosen for permanent storage
+// by the sampling mechanism of the tracer.
+func (c SpanContext) IsSampled() bool {
+	return (c.flags & flagSampled) == flagSampled
+}
+
+// IsDebug indicates whether sampling was explicitly requested by the service.
+func (c SpanContext) IsDebug() bool {
+	return (c.flags & flagDebug) == flagDebug
+}
+
+// IsValid indicates whether this context actually represents a valid trace.
+func (c SpanContext) IsValid() bool {
+	return c.traceID.IsValid() && c.spanID != 0
+}
+
+func (c SpanContext) String() string {
+	if c.traceID.High == 0 {
+		return fmt.Sprintf("%x:%x:%x:%x", c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.flags)
+	}
+	return fmt.Sprintf("%x%016x:%x:%x:%x", c.traceID.High, c.traceID.Low, uint64(c.spanID), uint64(c.parentID), c.flags)
+}
+
+// ContextFromString reconstructs the Context encoded in a string
+func ContextFromString(value string) (SpanContext, error) {
+	var context SpanContext
+	if value == "" {
+		return emptyContext, errEmptyTracerStateString
+	}
+	parts := strings.Split(value, ":")
+	if len(parts) != 4 {
+		return emptyContext, errMalformedTracerStateString
+	}
+	var err error
+	if context.traceID, err = TraceIDFromString(parts[0]); err != nil {
+		return emptyContext, err
+	}
+	if context.spanID, err = SpanIDFromString(parts[1]); err != nil {
+		return emptyContext, err
+	}
+	if context.parentID, err = SpanIDFromString(parts[2]); err != nil {
+		return emptyContext, err
+	}
+	flags, err := strconv.ParseUint(parts[3], 10, 8)
+	if err != nil {
+		return emptyContext, err
+	}
+	context.flags = byte(flags)
+	return context, nil
+}
+
+// TraceID returns the trace ID of this span context
+func (c SpanContext) TraceID() TraceID {
+	return c.traceID
+}
+
+// SpanID returns the span ID of this span context
+func (c SpanContext) SpanID() SpanID {
+	return c.spanID
+}
+
+// ParentID returns the parent span ID of this span context
+func (c SpanContext) ParentID() SpanID {
+	return c.parentID
+}
+
+// NewSpanContext creates a new instance of SpanContext
+func NewSpanContext(traceID TraceID, spanID, parentID SpanID, sampled bool, baggage map[string]string) SpanContext {
+	flags := byte(0)
+	if sampled {
+		flags = flagSampled
+	}
+	return SpanContext{
+		traceID:  traceID,
+		spanID:   spanID,
+		parentID: parentID,
+		flags:    flags,
+		baggage:  baggage}
+}
+
+// CopyFrom copies data from ctx into this context, including span identity and baggage.
+// TODO This is only used by interop.go. Remove once TChannel Go supports OpenTracing.
+func (c *SpanContext) CopyFrom(ctx *SpanContext) {
+	c.traceID = ctx.traceID
+	c.spanID = ctx.spanID
+	c.parentID = ctx.parentID
+	c.flags = ctx.flags
+	if l := len(ctx.baggage); l > 0 {
+		c.baggage = make(map[string]string, l)
+		for k, v := range ctx.baggage {
+			c.baggage[k] = v
+		}
+	} else {
+		c.baggage = nil
+	}
+}
+
+// WithBaggageItem creates a new context with an extra baggage item.
+func (c SpanContext) WithBaggageItem(key, value string) SpanContext {
+	var newBaggage map[string]string
+	if c.baggage == nil {
+		newBaggage = map[string]string{key: value}
+	} else {
+		newBaggage = make(map[string]string, len(c.baggage)+1)
+		for k, v := range c.baggage {
+			newBaggage[k] = v
+		}
+		newBaggage[key] = value
+	}
+	// Use positional parameters so the compiler will help catch new fields.
+	return SpanContext{c.traceID, c.spanID, c.parentID, c.flags, newBaggage, ""}
+}
+
+// isDebugIDContainerOnly returns true when the instance of the context is only
+// used to return the debug/correlation ID from extract() method. This happens
+// in the situation when "jaeger-debug-id" header is passed in the carrier to
+// the extract() method, but the request otherwise has no span context in it.
+// Previously this would've returned opentracing.ErrSpanContextNotFound from the
+// extract method, but now it returns a dummy context with only debugID filled in.
+//
+// See JaegerDebugHeader in constants.go
+// See textMapPropagator#Extract
+func (c *SpanContext) isDebugIDContainerOnly() bool {
+	return !c.traceID.IsValid() && c.debugID != ""
+}
+
+// ------- TraceID -------
+
+func (t TraceID) String() string {
+	if t.High == 0 {
+		return fmt.Sprintf("%x", t.Low)
+	}
+	return fmt.Sprintf("%x%016x", t.High, t.Low)
+}
+
+// TraceIDFromString creates a TraceID from a hexadecimal string
+func TraceIDFromString(s string) (TraceID, error) {
+	var hi, lo uint64
+	var err error
+	if len(s) > 32 {
+		return TraceID{}, fmt.Errorf("TraceID cannot be longer than 32 hex characters: %s", s)
+	} else if len(s) > 16 {
+		hiLen := len(s) - 16
+		if hi, err = strconv.ParseUint(s[0:hiLen], 16, 64); err != nil {
+			return TraceID{}, err
+		}
+		if lo, err = strconv.ParseUint(s[hiLen:], 16, 64); err != nil {
+			return TraceID{}, err
+		}
+	} else {
+		if lo, err = strconv.ParseUint(s, 16, 64); err != nil {
+			return TraceID{}, err
+		}
+	}
+	return TraceID{High: hi, Low: lo}, nil
+}
+
+// IsValid checks if the trace ID is valid, i.e. not zero.
+func (t TraceID) IsValid() bool {
+	return t.High != 0 || t.Low != 0
+}
+
+// ------- SpanID -------
+
+func (s SpanID) String() string {
+	return fmt.Sprintf("%x", uint64(s))
+}
+
+// SpanIDFromString creates a SpanID from a hexadecimal string
+func SpanIDFromString(s string) (SpanID, error) {
+	if len(s) > 16 {
+		return SpanID(0), fmt.Errorf("SpanID cannot be longer than 16 hex characters: %s", s)
+	}
+	id, err := strconv.ParseUint(s, 16, 64)
+	if err != nil {
+		return SpanID(0), err
+	}
+	return SpanID(id), nil
+}

vendor/github.com/uber/jaeger-client-go/contrib_observer.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	opentracing "github.com/opentracing/opentracing-go"
+)
+
+// ContribObserver can be registered with the Tracer to receive notifications
+// about new Spans. Modelled after github.com/opentracing-contrib/go-observer.
+type ContribObserver interface {
+	// Create and return a span observer. Called when a span starts.
+	// If the Observer is not interested in the given span, it must return (nil, false).
+	// E.g :
+	//     func StartSpan(opName string, opts ...opentracing.StartSpanOption) {
+	//         var sp opentracing.Span
+	//         sso := opentracing.StartSpanOptions{}
+	//         if spanObserver, ok := Observer.OnStartSpan(span, opName, sso); ok {
+	//             // we have a valid SpanObserver
+	//         }
+	//         ...
+	//     }
+	OnStartSpan(sp opentracing.Span, operationName string, options opentracing.StartSpanOptions) (ContribSpanObserver, bool)
+}
+
+// ContribSpanObserver is created by the Observer and receives notifications
+// about other Span events. This interface is meant to match
+// github.com/opentracing-contrib/go-observer, via duck typing, without
+// directly importing the go-observer package.
+type ContribSpanObserver interface {
+	OnSetOperationName(operationName string)
+	OnSetTag(key string, value interface{})
+	OnFinish(options opentracing.FinishOptions)
+}
+
+// wrapper observer for the old observers (see observer.go)
+type oldObserver struct {
+	obs Observer
+}
+
+func (o *oldObserver) OnStartSpan(sp opentracing.Span, operationName string, options opentracing.StartSpanOptions) (ContribSpanObserver, bool) {
+	spanObserver := o.obs.OnStartSpan(operationName, options)
+	return spanObserver, spanObserver != nil
+}

vendor/github.com/uber/jaeger-client-go/doc.go

@@ -0,0 +1,24 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package jaeger implements an OpenTracing (http://opentracing.io) Tracer.
+It is currently using Zipkin-compatible data model and can be directly
+itegrated with Zipkin backend (http://zipkin.io).
+
+For integration instructions please refer to the README:
+
+https://github.com/uber/jaeger-client-go/blob/master/README.md
+*/
+package jaeger

vendor/github.com/uber/jaeger-client-go/glide.lock

@@ -0,0 +1,89 @@
+hash: 3accf84f97bff4a91162736104c0e9b9790820712bd86db6fec5e665f7196a82
+updated: 2018-04-30T11:46:43.804556-04:00
+imports:
+- name: github.com/beorn7/perks
+  version: 3a771d992973f24aa725d07868b467d1ddfceafb
+  subpackages:
+  - quantile
+- name: github.com/codahale/hdrhistogram
+  version: 3a0bb77429bd3a61596f5e8a3172445844342120
+- name: github.com/crossdock/crossdock-go
+  version: 049aabb0122b03bc9bd30cab8f3f91fb60166361
+  subpackages:
+  - assert
+  - require
+- name: github.com/davecgh/go-spew
+  version: 8991bc29aa16c548c550c7ff78260e27b9ab7c73
+  subpackages:
+  - spew
+- name: github.com/golang/protobuf
+  version: bbd03ef6da3a115852eaf24c8a1c46aeb39aa175
+  subpackages:
+  - proto
+- name: github.com/matttproud/golang_protobuf_extensions
+  version: c12348ce28de40eed0136aa2b644d0ee0650e56c
+  subpackages:
+  - pbutil
+- name: github.com/opentracing/opentracing-go
+  version: 1949ddbfd147afd4d964a9f00b24eb291e0e7c38
+  subpackages:
+  - ext
+  - log
+- name: github.com/pkg/errors
+  version: 645ef00459ed84a119197bfb8d8205042c6df63d
+- name: github.com/pmezard/go-difflib
+  version: 792786c7400a136282c1664665ae0a8db921c6c2
+  subpackages:
+  - difflib
+- name: github.com/prometheus/client_golang
+  version: c5b7fccd204277076155f10851dad72b76a49317
+  subpackages:
+  - prometheus
+- name: github.com/prometheus/client_model
+  version: 99fa1f4be8e564e8a6b613da7fa6f46c9edafc6c
+  subpackages:
+  - go
+- name: github.com/prometheus/common
+  version: 38c53a9f4bfcd932d1b00bfc65e256a7fba6b37a
+  subpackages:
+  - expfmt
+  - internal/bitbucket.org/ww/goautoneg
+  - model
+- name: github.com/prometheus/procfs
+  version: 780932d4fbbe0e69b84c34c20f5c8d0981e109ea
+  subpackages:
+  - internal/util
+  - nfs
+  - xfs
+- name: github.com/stretchr/testify
+  version: 12b6f73e6084dad08a7c6e575284b177ecafbc71
+  subpackages:
+  - assert
+  - require
+  - suite
+- name: github.com/uber/jaeger-lib
+  version: 4267858c0679cd4e47cefed8d7f70fd386cfb567
+  subpackages:
+  - metrics
+  - metrics/prometheus
+  - metrics/testutils
+- name: go.uber.org/atomic
+  version: 8474b86a5a6f79c443ce4b2992817ff32cf208b8
+- name: go.uber.org/multierr
+  version: 3c4937480c32f4c13a875a1829af76c98ca3d40a
+- name: go.uber.org/zap
+  version: eeedf312bc6c57391d84767a4cd413f02a917974
+  subpackages:
+  - buffer
+  - internal/bufferpool
+  - internal/color
+  - internal/exit
+  - zapcore
+- name: golang.org/x/net
+  version: 6078986fec03a1dcc236c34816c71b0e05018fda
+  subpackages:
+  - context
+  - context/ctxhttp
+testImports:
+- name: github.com/uber-go/atomic
+  version: 8474b86a5a6f79c443ce4b2992817ff32cf208b8

vendor/github.com/uber/jaeger-client-go/glide.yaml

@@ -0,0 +1,22 @@
+package: github.com/uber/jaeger-client-go
+import:
+- package: github.com/opentracing/opentracing-go
+  version: ^1
+  subpackages:
+  - ext
+  - log
+- package: github.com/crossdock/crossdock-go
+- package: github.com/uber/jaeger-lib
+  version: ^1.2.1
+  subpackages:
+  - metrics
+- package: github.com/pkg/errors
+  version: ~0.8.0
+testImport:
+- package: github.com/stretchr/testify
+  subpackages:
+  - assert
+  - require
+  - suite
+- package: github.com/prometheus/client_golang
+  version: v0.8.0

vendor/github.com/uber/jaeger-client-go/header.go

@@ -0,0 +1,64 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+// HeadersConfig contains the values for the header keys that Jaeger will use.
+// These values may be either custom or default depending on whether custom
+// values were provided via a configuration.
+type HeadersConfig struct {
+	// JaegerDebugHeader is the name of HTTP header or a TextMap carrier key which,
+	// if found in the carrier, forces the trace to be sampled as "debug" trace.
+	// The value of the header is recorded as the tag on the root span, so that the
+	// trace can be found in the UI using this value as a correlation ID.
+	JaegerDebugHeader string `yaml:"jaegerDebugHeader"`
+
+	// JaegerBaggageHeader is the name of the HTTP header that is used to submit baggage.
+	// It differs from TraceBaggageHeaderPrefix in that it can be used only in cases where
+	// a root span does not exist.
+	JaegerBaggageHeader string `yaml:"jaegerBaggageHeader"`
+
+	// TraceContextHeaderName is the http header name used to propagate tracing context.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceContextHeaderName string `yaml:"TraceContextHeaderName"`
+
+	// TraceBaggageHeaderPrefix is the prefix for http headers used to propagate baggage.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceBaggageHeaderPrefix string `yaml:"traceBaggageHeaderPrefix"`
+}
+
+func (c *HeadersConfig) applyDefaults() *HeadersConfig {
+	if c.JaegerBaggageHeader == "" {
+		c.JaegerBaggageHeader = JaegerBaggageHeader
+	}
+	if c.JaegerDebugHeader == "" {
+		c.JaegerDebugHeader = JaegerDebugHeader
+	}
+	if c.TraceBaggageHeaderPrefix == "" {
+		c.TraceBaggageHeaderPrefix = TraceBaggageHeaderPrefix
+	}
+	if c.TraceContextHeaderName == "" {
+		c.TraceContextHeaderName = TraceContextHeaderName
+	}
+	return c
+}
+
+func getDefaultHeadersConfig() *HeadersConfig {
+	return &HeadersConfig{
+		JaegerDebugHeader:        JaegerDebugHeader,
+		JaegerBaggageHeader:      JaegerBaggageHeader,
+		TraceContextHeaderName:   TraceContextHeaderName,
+		TraceBaggageHeaderPrefix: TraceBaggageHeaderPrefix,
+	}
+}

vendor/github.com/uber/jaeger-client-go/internal/baggage/remote/options.go

@@ -0,0 +1,101 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"time"
+
+	"github.com/uber/jaeger-client-go"
+)
+
+const (
+	defaultMaxValueLength  = 2048
+	defaultRefreshInterval = time.Minute
+	defaultHostPort        = "localhost:5778"
+)
+
+// Option is a function that sets some option on the RestrictionManager
+type Option func(options *options)
+
+// Options is a factory for all available options
+var Options options
+
+type options struct {
+	denyBaggageOnInitializationFailure bool
+	metrics                            *jaeger.Metrics
+	logger                             jaeger.Logger
+	hostPort                           string
+	refreshInterval                    time.Duration
+}
+
+// DenyBaggageOnInitializationFailure creates an Option that determines the startup failure mode of RestrictionManager.
+// If DenyBaggageOnInitializationFailure is true, RestrictionManager will not allow any baggage to be written until baggage
+// restrictions have been retrieved from agent.
+// If DenyBaggageOnInitializationFailure is false, RestrictionManager will allow any baggage to be written until baggage
+// restrictions have been retrieved from agent.
+func (options) DenyBaggageOnInitializationFailure(b bool) Option {
+	return func(o *options) {
+		o.denyBaggageOnInitializationFailure = b
+	}
+}
+
+// Metrics creates an Option that initializes Metrics on the RestrictionManager, which is used to emit statistics.
+func (options) Metrics(m *jaeger.Metrics) Option {
+	return func(o *options) {
+		o.metrics = m
+	}
+}
+
+// Logger creates an Option that sets the logger used by the RestrictionManager.
+func (options) Logger(logger jaeger.Logger) Option {
+	return func(o *options) {
+		o.logger = logger
+	}
+}
+
+// HostPort creates an Option that sets the hostPort of the local agent that contains the baggage restrictions.
+func (options) HostPort(hostPort string) Option {
+	return func(o *options) {
+		o.hostPort = hostPort
+	}
+}
+
+// RefreshInterval creates an Option that sets how often the RestrictionManager will poll local agent for
+// the baggage restrictions.
+func (options) RefreshInterval(refreshInterval time.Duration) Option {
+	return func(o *options) {
+		o.refreshInterval = refreshInterval
+	}
+}
+
+func applyOptions(o ...Option) options {
+	opts := options{}
+	for _, option := range o {
+		option(&opts)
+	}
+	if opts.metrics == nil {
+		opts.metrics = jaeger.NewNullMetrics()
+	}
+	if opts.logger == nil {
+		opts.logger = jaeger.NullLogger
+	}
+	if opts.hostPort == "" {
+		opts.hostPort = defaultHostPort
+	}
+	if opts.refreshInterval == 0 {
+		opts.refreshInterval = defaultRefreshInterval
+	}
+	return opts
+}

vendor/github.com/uber/jaeger-client-go/internal/baggage/remote/restriction_manager.go

@@ -0,0 +1,157 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"fmt"
+	"net/url"
+	"sync"
+	"time"
+
+	"github.com/uber/jaeger-client-go/internal/baggage"
+	thrift "github.com/uber/jaeger-client-go/thrift-gen/baggage"
+	"github.com/uber/jaeger-client-go/utils"
+)
+
+type httpBaggageRestrictionManagerProxy struct {
+	url string
+}
+
+func newHTTPBaggageRestrictionManagerProxy(hostPort, serviceName string) *httpBaggageRestrictionManagerProxy {
+	v := url.Values{}
+	v.Set("service", serviceName)
+	return &httpBaggageRestrictionManagerProxy{
+		url: fmt.Sprintf("http://%s/baggageRestrictions?%s", hostPort, v.Encode()),
+	}
+}
+
+func (s *httpBaggageRestrictionManagerProxy) GetBaggageRestrictions(serviceName string) ([]*thrift.BaggageRestriction, error) {
+	var out []*thrift.BaggageRestriction
+	if err := utils.GetJSON(s.url, &out); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// RestrictionManager manages baggage restrictions by retrieving baggage restrictions from agent
+type RestrictionManager struct {
+	options
+
+	mux                sync.RWMutex
+	serviceName        string
+	restrictions       map[string]*baggage.Restriction
+	thriftProxy        thrift.BaggageRestrictionManager
+	pollStopped        sync.WaitGroup
+	stopPoll           chan struct{}
+	invalidRestriction *baggage.Restriction
+	validRestriction   *baggage.Restriction
+
+	// Determines if the manager has successfully retrieved baggage restrictions from agent
+	initialized bool
+}
+
+// NewRestrictionManager returns a BaggageRestrictionManager that polls the agent for the latest
+// baggage restrictions.
+func NewRestrictionManager(serviceName string, options ...Option) *RestrictionManager {
+	// TODO there is a developing use case where a single tracer can generate traces on behalf of many services.
+	// restrictionsMap will need to exist per service
+	opts := applyOptions(options...)
+	m := &RestrictionManager{
+		serviceName:        serviceName,
+		options:            opts,
+		restrictions:       make(map[string]*baggage.Restriction),
+		thriftProxy:        newHTTPBaggageRestrictionManagerProxy(opts.hostPort, serviceName),
+		stopPoll:           make(chan struct{}),
+		invalidRestriction: baggage.NewRestriction(false, 0),
+		validRestriction:   baggage.NewRestriction(true, defaultMaxValueLength),
+	}
+	m.pollStopped.Add(1)
+	go m.pollManager()
+	return m
+}
+
+// isReady returns true if the manager has retrieved baggage restrictions from the remote source.
+func (m *RestrictionManager) isReady() bool {
+	m.mux.RLock()
+	defer m.mux.RUnlock()
+	return m.initialized
+}
+
+// GetRestriction implements RestrictionManager#GetRestriction.
+func (m *RestrictionManager) GetRestriction(service, key string) *baggage.Restriction {
+	m.mux.RLock()
+	defer m.mux.RUnlock()
+	if !m.initialized {
+		if m.denyBaggageOnInitializationFailure {
+			return m.invalidRestriction
+		}
+		return m.validRestriction
+	}
+	if restriction, ok := m.restrictions[key]; ok {
+		return restriction
+	}
+	return m.invalidRestriction
+}
+
+// Close stops remote polling and closes the RemoteRestrictionManager.
+func (m *RestrictionManager) Close() error {
+	close(m.stopPoll)
+	m.pollStopped.Wait()
+	return nil
+}
+
+func (m *RestrictionManager) pollManager() {
+	defer m.pollStopped.Done()
+	// attempt to initialize baggage restrictions
+	if err := m.updateRestrictions(); err != nil {
+		m.logger.Error(fmt.Sprintf("Failed to initialize baggage restrictions: %s", err.Error()))
+	}
+	ticker := time.NewTicker(m.refreshInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			if err := m.updateRestrictions(); err != nil {
+				m.logger.Error(fmt.Sprintf("Failed to update baggage restrictions: %s", err.Error()))
+			}
+		case <-m.stopPoll:
+			return
+		}
+	}
+}
+
+func (m *RestrictionManager) updateRestrictions() error {
+	restrictions, err := m.thriftProxy.GetBaggageRestrictions(m.serviceName)
+	if err != nil {
+		m.metrics.BaggageRestrictionsUpdateFailure.Inc(1)
+		return err
+	}
+	newRestrictions := m.parseRestrictions(restrictions)
+	m.metrics.BaggageRestrictionsUpdateSuccess.Inc(1)
+	m.mux.Lock()
+	defer m.mux.Unlock()
+	m.initialized = true
+	m.restrictions = newRestrictions
+	return nil
+}
+
+func (m *RestrictionManager) parseRestrictions(restrictions []*thrift.BaggageRestriction) map[string]*baggage.Restriction {
+	setters := make(map[string]*baggage.Restriction, len(restrictions))
+	for _, restriction := range restrictions {
+		setters[restriction.BaggageKey] = baggage.NewRestriction(true, int(restriction.MaxValueLength))
+	}
+	return setters
+}

vendor/github.com/uber/jaeger-client-go/internal/baggage/restriction_manager.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package baggage
+
+const (
+	defaultMaxValueLength = 2048
+)
+
+// Restriction determines whether a baggage key is allowed and contains any restrictions on the baggage value.
+type Restriction struct {
+	keyAllowed     bool
+	maxValueLength int
+}
+
+// NewRestriction returns a new Restriction.
+func NewRestriction(keyAllowed bool, maxValueLength int) *Restriction {
+	return &Restriction{
+		keyAllowed:     keyAllowed,
+		maxValueLength: maxValueLength,
+	}
+}
+
+// KeyAllowed returns whether the baggage key for this restriction is allowed.
+func (r *Restriction) KeyAllowed() bool {
+	return r.keyAllowed
+}
+
+// MaxValueLength returns the max length for the baggage value.
+func (r *Restriction) MaxValueLength() int {
+	return r.maxValueLength
+}
+
+// RestrictionManager keeps track of valid baggage keys and their restrictions. The manager
+// will return a Restriction for a specific baggage key which will determine whether the baggage
+// key is allowed for the current service and any other applicable restrictions on the baggage
+// value.
+type RestrictionManager interface {
+	GetRestriction(service, key string) *Restriction
+}
+
+// DefaultRestrictionManager allows any baggage key.
+type DefaultRestrictionManager struct {
+	defaultRestriction *Restriction
+}
+
+// NewDefaultRestrictionManager returns a DefaultRestrictionManager.
+func NewDefaultRestrictionManager(maxValueLength int) *DefaultRestrictionManager {
+	if maxValueLength == 0 {
+		maxValueLength = defaultMaxValueLength
+	}
+	return &DefaultRestrictionManager{
+		defaultRestriction: &Restriction{keyAllowed: true, maxValueLength: maxValueLength},
+	}
+}
+
+// GetRestriction implements RestrictionManager#GetRestriction.
+func (m *DefaultRestrictionManager) GetRestriction(service, key string) *Restriction {
+	return m.defaultRestriction
+}

vendor/github.com/uber/jaeger-client-go/internal/spanlog/json.go

@@ -0,0 +1,81 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package spanlog
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/opentracing/opentracing-go/log"
+)
+
+type fieldsAsMap map[string]string
+
+// MaterializeWithJSON converts log Fields into JSON string
+// TODO refactor into pluggable materializer
+func MaterializeWithJSON(logFields []log.Field) ([]byte, error) {
+	fields := fieldsAsMap(make(map[string]string, len(logFields)))
+	for _, field := range logFields {
+		field.Marshal(fields)
+	}
+	if event, ok := fields["event"]; ok && len(fields) == 1 {
+		return []byte(event), nil
+	}
+	return json.Marshal(fields)
+}
+
+func (ml fieldsAsMap) EmitString(key, value string) {
+	ml[key] = value
+}
+
+func (ml fieldsAsMap) EmitBool(key string, value bool) {
+	ml[key] = fmt.Sprintf("%t", value)
+}
+
+func (ml fieldsAsMap) EmitInt(key string, value int) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitInt32(key string, value int32) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitInt64(key string, value int64) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitUint32(key string, value uint32) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitUint64(key string, value uint64) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitFloat32(key string, value float32) {
+	ml[key] = fmt.Sprintf("%f", value)
+}
+
+func (ml fieldsAsMap) EmitFloat64(key string, value float64) {
+	ml[key] = fmt.Sprintf("%f", value)
+}
+
+func (ml fieldsAsMap) EmitObject(key string, value interface{}) {
+	ml[key] = fmt.Sprintf("%+v", value)
+}
+
+func (ml fieldsAsMap) EmitLazyLogger(value log.LazyLogger) {
+	value(ml)
+}

vendor/github.com/uber/jaeger-client-go/internal/throttler/remote/options.go

@@ -0,0 +1,99 @@
+// Copyright (c) 2018 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"time"
+
+	"github.com/uber/jaeger-client-go"
+)
+
+const (
+	defaultHostPort        = "localhost:5778"
+	defaultRefreshInterval = time.Second * 5
+)
+
+// Option is a function that sets some option on the Throttler
+type Option func(options *options)
+
+// Options is a factory for all available options
+var Options options
+
+type options struct {
+	metrics                   *jaeger.Metrics
+	logger                    jaeger.Logger
+	hostPort                  string
+	refreshInterval           time.Duration
+	synchronousInitialization bool
+}
+
+// Metrics creates an Option that initializes Metrics on the Throttler, which is used to emit statistics.
+func (options) Metrics(m *jaeger.Metrics) Option {
+	return func(o *options) {
+		o.metrics = m
+	}
+}
+
+// Logger creates an Option that sets the logger used by the Throttler.
+func (options) Logger(logger jaeger.Logger) Option {
+	return func(o *options) {
+		o.logger = logger
+	}
+}
+
+// HostPort creates an Option that sets the hostPort of the local agent that keeps track of credits.
+func (options) HostPort(hostPort string) Option {
+	return func(o *options) {
+		o.hostPort = hostPort
+	}
+}
+
+// RefreshInterval creates an Option that sets how often the Throttler will poll local agent for
+// credits.
+func (options) RefreshInterval(refreshInterval time.Duration) Option {
+	return func(o *options) {
+		o.refreshInterval = refreshInterval
+	}
+}
+
+// SynchronousInitialization creates an Option that determines whether the throttler should synchronously
+// fetch credits from the agent when an operation is seen for the first time. This should be set to true
+// if the client will be used by a short lived service that needs to ensure that credits are fetched upfront
+// such that sampling or throttling occurs.
+func (options) SynchronousInitialization(b bool) Option {
+	return func(o *options) {
+		o.synchronousInitialization = b
+	}
+}
+
+func applyOptions(o ...Option) options {
+	opts := options{}
+	for _, option := range o {
+		option(&opts)
+	}
+	if opts.metrics == nil {
+		opts.metrics = jaeger.NewNullMetrics()
+	}
+	if opts.logger == nil {
+		opts.logger = jaeger.NullLogger
+	}
+	if opts.hostPort == "" {
+		opts.hostPort = defaultHostPort
+	}
+	if opts.refreshInterval == 0 {
+		opts.refreshInterval = defaultRefreshInterval
+	}
+	return opts
+}

vendor/github.com/uber/jaeger-client-go/internal/throttler/remote/throttler.go

@@ -0,0 +1,216 @@
+// Copyright (c) 2018 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"fmt"
+	"net/url"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+
+	"github.com/uber/jaeger-client-go"
+	"github.com/uber/jaeger-client-go/utils"
+)
+
+const (
+	// minimumCredits is the minimum amount of credits necessary to not be throttled.
+	// i.e. if currentCredits > minimumCredits, then the operation will not be throttled.
+	minimumCredits = 1.0
+)
+
+var (
+	errorUUIDNotSet = errors.New("Throttler UUID must be set")
+)
+
+type operationBalance struct {
+	Operation string  `json:"operation"`
+	Balance   float64 `json:"balance"`
+}
+
+type creditResponse struct {
+	Balances []operationBalance `json:"balances"`
+}
+
+type httpCreditManagerProxy struct {
+	hostPort string
+}
+
+func newHTTPCreditManagerProxy(hostPort string) *httpCreditManagerProxy {
+	return &httpCreditManagerProxy{
+		hostPort: hostPort,
+	}
+}
+
+// N.B. Operations list must not be empty.
+func (m *httpCreditManagerProxy) FetchCredits(uuid, serviceName string, operations []string) (*creditResponse, error) {
+	params := url.Values{}
+	params.Set("service", serviceName)
+	params.Set("uuid", uuid)
+	for _, op := range operations {
+		params.Add("operations", op)
+	}
+	var resp creditResponse
+	if err := utils.GetJSON(fmt.Sprintf("http://%s/credits?%s", m.hostPort, params.Encode()), &resp); err != nil {
+		return nil, errors.Wrap(err, "Failed to receive credits from agent")
+	}
+	return &resp, nil
+}
+
+// Throttler retrieves credits from agent and uses it to throttle operations.
+type Throttler struct {
+	options
+
+	mux           sync.RWMutex
+	service       string
+	uuid          atomic.Value
+	creditManager *httpCreditManagerProxy
+	credits       map[string]float64 // map of operation->credits
+	close         chan struct{}
+	stopped       sync.WaitGroup
+}
+
+// NewThrottler returns a Throttler that polls agent for credits and uses them to throttle
+// the service.
+func NewThrottler(service string, options ...Option) *Throttler {
+	opts := applyOptions(options...)
+	creditManager := newHTTPCreditManagerProxy(opts.hostPort)
+	t := &Throttler{
+		options:       opts,
+		creditManager: creditManager,
+		service:       service,
+		credits:       make(map[string]float64),
+		close:         make(chan struct{}),
+	}
+	t.stopped.Add(1)
+	go t.pollManager()
+	return t
+}
+
+// IsAllowed implements Throttler#IsAllowed.
+func (t *Throttler) IsAllowed(operation string) bool {
+	t.mux.Lock()
+	defer t.mux.Unlock()
+	value, ok := t.credits[operation]
+	if !ok || value == 0 {
+		if !ok {
+			// NOTE: This appears to be a no-op at first glance, but it stores
+			// the operation key in the map. Necessary for functionality of
+			// Throttler#operations method.
+			t.credits[operation] = 0
+		}
+		if !t.synchronousInitialization {
+			t.metrics.ThrottledDebugSpans.Inc(1)
+			return false
+		}
+		// If it is the first time this operation is being checked, synchronously fetch
+		// the credits.
+		credits, err := t.fetchCredits([]string{operation})
+		if err != nil {
+			// Failed to receive credits from agent, try again next time
+			t.logger.Error("Failed to fetch credits: " + err.Error())
+			return false
+		}
+		if len(credits.Balances) == 0 {
+			// This shouldn't happen but just in case
+			return false
+		}
+		for _, opBalance := range credits.Balances {
+			t.credits[opBalance.Operation] += opBalance.Balance
+		}
+	}
+	return t.isAllowed(operation)
+}
+
+// Close stops the throttler from fetching credits from remote.
+func (t *Throttler) Close() error {
+	close(t.close)
+	t.stopped.Wait()
+	return nil
+}
+
+// SetProcess implements ProcessSetter#SetProcess. It's imperative that the UUID is set before any remote
+// requests are made.
+func (t *Throttler) SetProcess(process jaeger.Process) {
+	if process.UUID != "" {
+		t.uuid.Store(process.UUID)
+	}
+}
+
+// N.B. This function must be called with the Write Lock
+func (t *Throttler) isAllowed(operation string) bool {
+	credits := t.credits[operation]
+	if credits < minimumCredits {
+		t.metrics.ThrottledDebugSpans.Inc(1)
+		return false
+	}
+	t.credits[operation] = credits - minimumCredits
+	return true
+}
+
+func (t *Throttler) pollManager() {
+	defer t.stopped.Done()
+	ticker := time.NewTicker(t.refreshInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			t.refreshCredits()
+		case <-t.close:
+			return
+		}
+	}
+}
+
+func (t *Throttler) operations() []string {
+	t.mux.RLock()
+	defer t.mux.RUnlock()
+	operations := make([]string, 0, len(t.credits))
+	for op := range t.credits {
+		operations = append(operations, op)
+	}
+	return operations
+}
+
+func (t *Throttler) refreshCredits() {
+	operations := t.operations()
+	if len(operations) == 0 {
+		return
+	}
+	newCredits, err := t.fetchCredits(operations)
+	if err != nil {
+		t.metrics.ThrottlerUpdateFailure.Inc(1)
+		t.logger.Error("Failed to fetch credits: " + err.Error())
+		return
+	}
+	t.metrics.ThrottlerUpdateSuccess.Inc(1)
+
+	t.mux.Lock()
+	defer t.mux.Unlock()
+	for _, opBalance := range newCredits.Balances {
+		t.credits[opBalance.Operation] += opBalance.Balance
+	}
+}
+
+func (t *Throttler) fetchCredits(operations []string) (*creditResponse, error) {
+	uuid := t.uuid.Load()
+	uuidStr, _ := uuid.(string)
+	if uuid == nil || uuidStr == "" {
+		return nil, errorUUIDNotSet
+	}
+	return t.creditManager.FetchCredits(uuidStr, t.service, operations)
+}

vendor/github.com/uber/jaeger-client-go/internal/throttler/throttler.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2018 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package throttler
+
+// Throttler is used to rate limits operations. For example, given how debug spans
+// are always sampled, a throttler can be enabled per client to rate limit the amount
+// of debug spans a client can start.
+type Throttler interface {
+	// IsAllowed determines whether the operation should be allowed and not be
+	// throttled.
+	IsAllowed(operation string) bool
+}
+
+// DefaultThrottler doesn't throttle at all.
+type DefaultThrottler struct{}
+
+// IsAllowed implements Throttler#IsAllowed.
+func (t DefaultThrottler) IsAllowed(operation string) bool {
+	return true
+}

vendor/github.com/uber/jaeger-client-go/interop.go

@@ -0,0 +1,55 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"github.com/opentracing/opentracing-go"
+)
+
+// TODO this file should not be needed after TChannel PR.
+
+type formatKey int
+
+// SpanContextFormat is a constant used as OpenTracing Format.
+// Requires *SpanContext as carrier.
+// This format is intended for interop with TChannel or other Zipkin-like tracers.
+const SpanContextFormat formatKey = iota
+
+type jaegerTraceContextPropagator struct {
+	tracer *Tracer
+}
+
+func (p *jaegerTraceContextPropagator) Inject(
+	ctx SpanContext,
+	abstractCarrier interface{},
+) error {
+	carrier, ok := abstractCarrier.(*SpanContext)
+	if !ok {
+		return opentracing.ErrInvalidCarrier
+	}
+
+	carrier.CopyFrom(&ctx)
+	return nil
+}
+
+func (p *jaegerTraceContextPropagator) Extract(abstractCarrier interface{}) (SpanContext, error) {
+	carrier, ok := abstractCarrier.(*SpanContext)
+	if !ok {
+		return emptyContext, opentracing.ErrInvalidCarrier
+	}
+	ctx := new(SpanContext)
+	ctx.CopyFrom(carrier)
+	return *ctx, nil
+}

vendor/github.com/uber/jaeger-client-go/jaeger_tag.go

@@ -0,0 +1,84 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"fmt"
+
+	"github.com/opentracing/opentracing-go/log"
+
+	j "github.com/uber/jaeger-client-go/thrift-gen/jaeger"
+)
+
+type tags []*j.Tag
+
+// ConvertLogsToJaegerTags converts log Fields into jaeger tags.
+func ConvertLogsToJaegerTags(logFields []log.Field) []*j.Tag {
+	fields := tags(make([]*j.Tag, 0, len(logFields)))
+	for _, field := range logFields {
+		field.Marshal(&fields)
+	}
+	return fields
+}
+
+func (t *tags) EmitString(key, value string) {
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_STRING, VStr: &value})
+}
+
+func (t *tags) EmitBool(key string, value bool) {
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_BOOL, VBool: &value})
+}
+
+func (t *tags) EmitInt(key string, value int) {
+	vLong := int64(value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_LONG, VLong: &vLong})
+}
+
+func (t *tags) EmitInt32(key string, value int32) {
+	vLong := int64(value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_LONG, VLong: &vLong})
+}
+
+func (t *tags) EmitInt64(key string, value int64) {
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_LONG, VLong: &value})
+}
+
+func (t *tags) EmitUint32(key string, value uint32) {
+	vLong := int64(value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_LONG, VLong: &vLong})
+}
+
+func (t *tags) EmitUint64(key string, value uint64) {
+	vLong := int64(value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_LONG, VLong: &vLong})
+}
+
+func (t *tags) EmitFloat32(key string, value float32) {
+	vDouble := float64(value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_DOUBLE, VDouble: &vDouble})
+}
+
+func (t *tags) EmitFloat64(key string, value float64) {
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_DOUBLE, VDouble: &value})
+}
+
+func (t *tags) EmitObject(key string, value interface{}) {
+	vStr := fmt.Sprintf("%+v", value)
+	*t = append(*t, &j.Tag{Key: key, VType: j.TagType_STRING, VStr: &vStr})
+}
+
+func (t *tags) EmitLazyLogger(value log.LazyLogger) {
+	value(t)
+}

vendor/github.com/uber/jaeger-client-go/jaeger_thrift_span.go

@@ -0,0 +1,179 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"time"
+
+	"github.com/opentracing/opentracing-go"
+
+	j "github.com/uber/jaeger-client-go/thrift-gen/jaeger"
+	"github.com/uber/jaeger-client-go/utils"
+)
+
+// BuildJaegerThrift builds jaeger span based on internal span.
+func BuildJaegerThrift(span *Span) *j.Span {
+	span.Lock()
+	defer span.Unlock()
+	startTime := utils.TimeToMicrosecondsSinceEpochInt64(span.startTime)
+	duration := span.duration.Nanoseconds() / int64(time.Microsecond)
+	jaegerSpan := &j.Span{
+		TraceIdLow:    int64(span.context.traceID.Low),
+		TraceIdHigh:   int64(span.context.traceID.High),
+		SpanId:        int64(span.context.spanID),
+		ParentSpanId:  int64(span.context.parentID),
+		OperationName: span.operationName,
+		Flags:         int32(span.context.flags),
+		StartTime:     startTime,
+		Duration:      duration,
+		Tags:          buildTags(span.tags, span.tracer.options.maxTagValueLength),
+		Logs:          buildLogs(span.logs),
+		References:    buildReferences(span.references),
+	}
+	return jaegerSpan
+}
+
+// BuildJaegerProcessThrift creates a thrift Process type.
+func BuildJaegerProcessThrift(span *Span) *j.Process {
+	span.Lock()
+	defer span.Unlock()
+	return buildJaegerProcessThrift(span.tracer)
+}
+
+func buildJaegerProcessThrift(tracer *Tracer) *j.Process {
+	process := &j.Process{
+		ServiceName: tracer.serviceName,
+		Tags:        buildTags(tracer.tags, tracer.options.maxTagValueLength),
+	}
+	if tracer.process.UUID != "" {
+		process.Tags = append(process.Tags, &j.Tag{Key: TracerUUIDTagKey, VStr: &tracer.process.UUID, VType: j.TagType_STRING})
+	}
+	return process
+}
+
+func buildTags(tags []Tag, maxTagValueLength int) []*j.Tag {
+	jTags := make([]*j.Tag, 0, len(tags))
+	for _, tag := range tags {
+		jTag := buildTag(&tag, maxTagValueLength)
+		jTags = append(jTags, jTag)
+	}
+	return jTags
+}
+
+func buildLogs(logs []opentracing.LogRecord) []*j.Log {
+	jLogs := make([]*j.Log, 0, len(logs))
+	for _, log := range logs {
+		jLog := &j.Log{
+			Timestamp: utils.TimeToMicrosecondsSinceEpochInt64(log.Timestamp),
+			Fields:    ConvertLogsToJaegerTags(log.Fields),
+		}
+		jLogs = append(jLogs, jLog)
+	}
+	return jLogs
+}
+
+func buildTag(tag *Tag, maxTagValueLength int) *j.Tag {
+	jTag := &j.Tag{Key: tag.key}
+	switch value := tag.value.(type) {
+	case string:
+		vStr := truncateString(value, maxTagValueLength)
+		jTag.VStr = &vStr
+		jTag.VType = j.TagType_STRING
+	case []byte:
+		if len(value) > maxTagValueLength {
+			value = value[:maxTagValueLength]
+		}
+		jTag.VBinary = value
+		jTag.VType = j.TagType_BINARY
+	case int:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case uint:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case int8:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case uint8:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case int16:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case uint16:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case int32:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case uint32:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case int64:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case uint64:
+		vLong := int64(value)
+		jTag.VLong = &vLong
+		jTag.VType = j.TagType_LONG
+	case float32:
+		vDouble := float64(value)
+		jTag.VDouble = &vDouble
+		jTag.VType = j.TagType_DOUBLE
+	case float64:
+		vDouble := float64(value)
+		jTag.VDouble = &vDouble
+		jTag.VType = j.TagType_DOUBLE
+	case bool:
+		vBool := value
+		jTag.VBool = &vBool
+		jTag.VType = j.TagType_BOOL
+	default:
+		vStr := truncateString(stringify(value), maxTagValueLength)
+		jTag.VStr = &vStr
+		jTag.VType = j.TagType_STRING
+	}
+	return jTag
+}
+
+func buildReferences(references []Reference) []*j.SpanRef {
+	retMe := make([]*j.SpanRef, 0, len(references))
+	for _, ref := range references {
+		if ref.Type == opentracing.ChildOfRef {
+			retMe = append(retMe, spanRef(ref.Context, j.SpanRefType_CHILD_OF))
+		} else if ref.Type == opentracing.FollowsFromRef {
+			retMe = append(retMe, spanRef(ref.Context, j.SpanRefType_FOLLOWS_FROM))
+		}
+	}
+	return retMe
+}
+
+func spanRef(ctx SpanContext, refType j.SpanRefType) *j.SpanRef {
+	return &j.SpanRef{
+		RefType:     refType,
+		TraceIdLow:  int64(ctx.traceID.Low),
+		TraceIdHigh: int64(ctx.traceID.High),
+		SpanId:      int64(ctx.spanID),
+	}
+}

vendor/github.com/uber/jaeger-client-go/log/logger.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package log
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"sync"
+)
+
+// Logger provides an abstract interface for logging from Reporters.
+// Applications can provide their own implementation of this interface to adapt
+// reporters logging to whatever logging library they prefer (stdlib log,
+// logrus, go-logging, etc).
+type Logger interface {
+	// Error logs a message at error priority
+	Error(msg string)
+
+	// Infof logs a message at info priority
+	Infof(msg string, args ...interface{})
+}
+
+// StdLogger is implementation of the Logger interface that delegates to default `log` package
+var StdLogger = &stdLogger{}
+
+type stdLogger struct{}
+
+func (l *stdLogger) Error(msg string) {
+	log.Printf("ERROR: %s", msg)
+}
+
+// Infof logs a message at info priority
+func (l *stdLogger) Infof(msg string, args ...interface{}) {
+	log.Printf(msg, args...)
+}
+
+// NullLogger is implementation of the Logger interface that is no-op
+var NullLogger = &nullLogger{}
+
+type nullLogger struct{}
+
+func (l *nullLogger) Error(msg string)                      {}
+func (l *nullLogger) Infof(msg string, args ...interface{}) {}
+
+// BytesBufferLogger implements Logger backed by a bytes.Buffer.
+type BytesBufferLogger struct {
+	mux sync.Mutex
+	buf bytes.Buffer
+}
+
+// Error implements Logger.
+func (l *BytesBufferLogger) Error(msg string) {
+	l.mux.Lock()
+	l.buf.WriteString(fmt.Sprintf("ERROR: %s\n", msg))
+	l.mux.Unlock()
+}
+
+// Infof implements Logger.
+func (l *BytesBufferLogger) Infof(msg string, args ...interface{}) {
+	l.mux.Lock()
+	l.buf.WriteString("INFO: " + fmt.Sprintf(msg, args...) + "\n")
+	l.mux.Unlock()
+}
+
+// String returns string representation of the underlying buffer.
+func (l *BytesBufferLogger) String() string {
+	l.mux.Lock()
+	defer l.mux.Unlock()
+	return l.buf.String()
+}
+
+// Flush empties the underlying buffer.
+func (l *BytesBufferLogger) Flush() {
+	l.mux.Lock()
+	defer l.mux.Unlock()
+	l.buf.Reset()
+}

vendor/github.com/uber/jaeger-client-go/logger.go

@@ -0,0 +1,53 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import "log"
+
+// NB This will be deprecated in 3.0.0, please use jaeger-client-go/log/logger instead.
+
+// Logger provides an abstract interface for logging from Reporters.
+// Applications can provide their own implementation of this interface to adapt
+// reporters logging to whatever logging library they prefer (stdlib log,
+// logrus, go-logging, etc).
+type Logger interface {
+	// Error logs a message at error priority
+	Error(msg string)
+
+	// Infof logs a message at info priority
+	Infof(msg string, args ...interface{})
+}
+
+// StdLogger is implementation of the Logger interface that delegates to default `log` package
+var StdLogger = &stdLogger{}
+
+type stdLogger struct{}
+
+func (l *stdLogger) Error(msg string) {
+	log.Printf("ERROR: %s", msg)
+}
+
+// Infof logs a message at info priority
+func (l *stdLogger) Infof(msg string, args ...interface{}) {
+	log.Printf(msg, args...)
+}
+
+// NullLogger is implementation of the Logger interface that delegates to default `log` package
+var NullLogger = &nullLogger{}
+
+type nullLogger struct{}
+
+func (l *nullLogger) Error(msg string)                      {}
+func (l *nullLogger) Infof(msg string, args ...interface{}) {}

vendor/github.com/uber/jaeger-client-go/metrics.go

@@ -0,0 +1,107 @@
+// Copyright (c) 2017-2018 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"github.com/uber/jaeger-lib/metrics"
+)
+
+// Metrics is a container of all stats emitted by Jaeger tracer.
+type Metrics struct {
+	// Number of traces started by this tracer as sampled
+	TracesStartedSampled metrics.Counter `metric:"traces" tags:"state=started,sampled=y"`
+
+	// Number of traces started by this tracer as not sampled
+	TracesStartedNotSampled metrics.Counter `metric:"traces" tags:"state=started,sampled=n"`
+
+	// Number of externally started sampled traces this tracer joined
+	TracesJoinedSampled metrics.Counter `metric:"traces" tags:"state=joined,sampled=y"`
+
+	// Number of externally started not-sampled traces this tracer joined
+	TracesJoinedNotSampled metrics.Counter `metric:"traces" tags:"state=joined,sampled=n"`
+
+	// Number of sampled spans started by this tracer
+	SpansStartedSampled metrics.Counter `metric:"started_spans" tags:"sampled=y"`
+
+	// Number of unsampled spans started by this tracer
+	SpansStartedNotSampled metrics.Counter `metric:"started_spans" tags:"sampled=n"`
+
+	// Number of spans finished by this tracer
+	SpansFinished metrics.Counter `metric:"finished_spans"`
+
+	// Number of errors decoding tracing context
+	DecodingErrors metrics.Counter `metric:"span_context_decoding_errors"`
+
+	// Number of spans successfully reported
+	ReporterSuccess metrics.Counter `metric:"reporter_spans" tags:"result=ok"`
+
+	// Number of spans not reported due to a Sender failure
+	ReporterFailure metrics.Counter `metric:"reporter_spans" tags:"result=err"`
+
+	// Number of spans dropped due to internal queue overflow
+	ReporterDropped metrics.Counter `metric:"reporter_spans" tags:"result=dropped"`
+
+	// Current number of spans in the reporter queue
+	ReporterQueueLength metrics.Gauge `metric:"reporter_queue_length"`
+
+	// Number of times the Sampler succeeded to retrieve sampling strategy
+	SamplerRetrieved metrics.Counter `metric:"sampler_queries" tags:"result=ok"`
+
+	// Number of times the Sampler failed to retrieve sampling strategy
+	SamplerQueryFailure metrics.Counter `metric:"sampler_queries" tags:"result=err"`
+
+	// Number of times the Sampler succeeded to retrieve and update sampling strategy
+	SamplerUpdated metrics.Counter `metric:"sampler_updates" tags:"result=ok"`
+
+	// Number of times the Sampler failed to update sampling strategy
+	SamplerUpdateFailure metrics.Counter `metric:"sampler_updates" tags:"result=err"`
+
+	// Number of times baggage was successfully written or updated on spans.
+	BaggageUpdateSuccess metrics.Counter `metric:"baggage_updates" tags:"result=ok"`
+
+	// Number of times baggage failed to write or update on spans.
+	BaggageUpdateFailure metrics.Counter `metric:"baggage_updates" tags:"result=err"`
+
+	// Number of times baggage was truncated as per baggage restrictions.
+	BaggageTruncate metrics.Counter `metric:"baggage_truncations"`
+
+	// Number of times baggage restrictions were successfully updated.
+	BaggageRestrictionsUpdateSuccess metrics.Counter `metric:"baggage_restrictions_updates" tags:"result=ok"`
+
+	// Number of times baggage restrictions failed to update.
+	BaggageRestrictionsUpdateFailure metrics.Counter `metric:"baggage_restrictions_updates" tags:"result=err"`
+
+	// Number of times debug spans were throttled.
+	ThrottledDebugSpans metrics.Counter `metric:"throttled_debug_spans"`
+
+	// Number of times throttler successfully updated.
+	ThrottlerUpdateSuccess metrics.Counter `metric:"throttler_updates" tags:"result=ok"`
+
+	// Number of times throttler failed to update.
+	ThrottlerUpdateFailure metrics.Counter `metric:"throttler_updates" tags:"result=err"`
+}
+
+// NewMetrics creates a new Metrics struct and initializes it.
+func NewMetrics(factory metrics.Factory, globalTags map[string]string) *Metrics {
+	m := &Metrics{}
+	// TODO the namespace "jaeger" should be configurable (e.g. in all-in-one "jaeger-client" would make more sense)
+	metrics.Init(m, factory.Namespace("jaeger", nil), globalTags)
+	return m
+}
+
+// NewNullMetrics creates a new Metrics struct that won't report any metrics.
+func NewNullMetrics() *Metrics {
+	return NewMetrics(metrics.NullFactory, nil)
+}