virtigo/http.go

package main

import (
	"fmt"
	"net/http"
	"strings"

	pb "go.wit.com/lib/protobuf/virtbuf"
	"go.wit.com/lib/virtigoxml"
	"go.wit.com/log"
)

// remove '?' part and trailing '/'
func cleanURL(url string) string {
	url = "/" + strings.Trim(url, "/")
	return url
}

func okHandler(w http.ResponseWriter, r *http.Request) {
	var route string
	route = cleanURL(r.URL.Path)

	// is the cluster running what it should?
	if route == "/droplets" {
		for _, d := range me.cluster.Droplets {
			var msg string
			if d.StartState == pb.DropletState_ON {
				msg = "(should be on)"
			}
			switch d.CurrentState {
			case pb.DropletState_ON:
				fmt.Fprintln(w, d.Hostname, "ON")
			case pb.DropletState_OFF:
				fmt.Fprintln(w, d.Hostname, msg)
			default:
				fmt.Fprintln(w, d.Hostname, "? state:", d.CurrentState, msg)
			}
		}
		return
	}

	// show only what droplets should be running but are missing
	if route == "/missing" {
		var count int
		var missing int
		for _, d := range me.cluster.Droplets {
			if d.StartState != pb.DropletState_ON {
				continue
			}
			count += 1
			if d.CurrentState == pb.DropletState_ON {
				continue
			}
			missing += 1
			fmt.Fprintln(w, d.Hostname, "current state:", d.CurrentState)
		}
		if missing == 0 {
			fmt.Fprintln(w, "all", count, "droplets set to run are running")
		} else {
			fmt.Fprintln(w, missing, "droplets missing")
			fmt.Fprintln(w, count, "droplets should be running")
		}
		return
	}

	if route == "/favicon.ico" {
		// w.Header().Set("Content-Type", "image/svg+xml")
		w.Header().Set("Content-Type", "image/png")
		writeFile(w, "ipv6.png")
		return
	}

	if route == "/goReference.svg" {
		w.Header().Set("Content-Type", "image/svg+xml")
		writeFile(w, "goReference.svg")
		return
	}

	if route == "/uptime" {
		ok, s := clusterHealthy()
		if ok {
			log.Info("Handling URL:", route, "cluster is ok", s)
			fmt.Fprintln(w, s)
		} else {
			log.Info("Handling URL:", route, "cluster is not right yet", s)
			fmt.Fprintln(w, s)
		}
		return
	}

	if route == "/start" {
		hostname := r.URL.Query().Get("hostname")
		if hostname == "" {
			log.Warn("start failed. hostname is blank", cleanURL(r.URL.Path))
			fmt.Fprintln(w, "start failed. hostname is blank", cleanURL(r.URL.Path))
			return
		}
		log.Warn("hostname is", hostname)
		fmt.Fprintln(w, "hostname is", hostname)

		// log.Warn("Handling URL:", tmp, "start droplet", start)
		result, err := Start(hostname)
		if err == nil {
			fmt.Fprintln(w, result)
			fmt.Fprintln(w, hostname, "started output ok")
			fmt.Fprintln(w, hostname, "need to parse the output here")
			fmt.Fprintln(w, hostname, "todo: switch to protobuf here")
		} else {
			fmt.Fprintln(w, result)
			fmt.Fprintln(w, err)
			fmt.Fprintln(w, hostname, "start failed")
		}
		return
	}

	if route == "/dumpcluster" {
		dumpCluster(w)
		return
	}

	if route == "/dumpdroplets" {
		dumpDroplets(w)
		return
	}

	if route == "/dumplibvirtxml" {
		virtigoxml.DumpLibvirtxmlDomainNames()
		return
	}

	log.Warn("BAD URL =", route)
	fmt.Fprintln(w, "BAD URL tmp =", route)
}

// write a file out to the http socket
func writeFile(w http.ResponseWriter, filename string) {
	fullname := "resources/" + filename
	pfile, err := resources.ReadFile(fullname)
	if err != nil {
		log.Println("ERROR:", err)
		// w.Write(pfile)
		return
	}

	var repohtml string
	repohtml = string(pfile)
	if filename == "goReference.svg" {
		w.Header().Set("Content-Type", "image/svg+xml")
	}
	fmt.Fprintln(w, repohtml)
	log.Println("writeFile() found internal file:", filename)
}

// starts and sits waiting for HTTP requests
func startHTTP() {
	http.HandleFunc("/", okHandler)

	p := fmt.Sprintf(":%d", argv.Port)
	log.Println("Running on port", p)

	err := http.ListenAndServe(p, nil)
	if err != nil {
		log.Println("Error starting server:", err)
	}
}