add some double checking on writing config files

Signed-off-by: Jeff Carr <jcarr@wit.com>

configfiles.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -10,19 +11,43 @@ import (
 	"go.wit.com/log"
 )
 
-func readConfigFile() {
+var ErrorNoFile error = errors.New("missing file")
+var ErrorParse error = errors.New("invalid json")
+
+// something is wrong somewhere and sometimes the 
+// protobuf json files get written out with garbage
+func cfgfile() {
+	err := readConfigFile("virtigo.json")
+	if err == nil {
+		return
+	}
+	if err == ErrorParse {
+		os.Exit(-1)
+	}
+	err = readConfigFile("virtigo.json.last")
+	if err == nil {
+		log.Info("read json failed", err)
+		os.Exit(-1)
+	}
+	if err == ErrorNoFile {
+		log.Info("no config file created yet", err)
+		os.Exit(-1)
+	}
+}
+
+func readConfigFile(filename string) error {
 	me.cluster = new(pb.Cluster)
-	fullname := filepath.Join(os.Getenv("VIRTIGO_HOME"), "virtigo.json")
+	fullname := filepath.Join(os.Getenv("VIRTIGO_HOME"), filename)
 	pfile, err := os.ReadFile(fullname)
 	if err != nil {
 		log.Info("open config file :", err)
-		return
+		return ErrorNoFile
 	}
 	err = me.cluster.UnmarshalJSON(pfile)
 	if err != nil {
 		log.Info("read json failed", err)
 		os.Exit(-1)
-		return
+		return ErrorParse
 	}
 
 	// initialize each hypervisor
@@ -53,6 +78,8 @@ func readConfigFile() {
 		me.droplets = append(me.droplets, d)
 		log.Log(EVENT, "config new droplet", d.pb.Hostname, d.pb.StartState, d.pb.PreferredHypervisor)
 	}
+
+	return nil
 }
 
 func writeConfigFile() {

main.go

@@ -35,8 +35,7 @@ func main() {
 		log.DaemonMode(true)
 	}
 
-	readConfigFile()
-	// writeConfigFile()
+	cfgfile()
 
 	// initialize the grid as unstable
 	me.unstable = time.Now()