Merge pull request #16 from vshn/debug_raceconditions

This commit fixes a racecondition that was causing hangs during backups
on a few clusters. Also added the `--race` flag to the automated
integration test, to detect if new race conditions are introduced in new
releases.

.vscode/settings.json

@@ -3,6 +3,7 @@
   "go.testTimeout": "120s",
   "go.testFlags": [
     "-v",
+    "--race",
   ],
   "go.testEnvVars": {
     "RESTIC_REPOSITORY":"s3:http://localhost:9000/baas1",

restic/genericCommand.go

@@ -91,6 +91,7 @@ func (g *genericCommand) exec(args []string, options commandOptions) {
 	commandStderr, err := cmd.StderrPipe()
 
 	finished := make(chan error, 0)
+	defer close(finished)
 
 	err = cmd.Start()
 	if err != nil {
@@ -103,18 +104,20 @@ func (g *genericCommand) exec(args []string, options commandOptions) {
 
 	go func() {
 		var collectErr error
+		stdOut, collectErr := g.collectOutput(commandStdout, options.print, options.output)
+		finished <- collectErr
 		g.mutex.Lock()
-		g.stdOut, collectErr = g.collectOutput(commandStdout, options.print, options.output)
+		g.stdOut = stdOut
 		g.mutex.Unlock()
-		finished <- collectErr
 	}()
 
 	go func() {
 		var collectErr error
+		stdErr, collectErr := g.collectOutput(commandStderr, options.print, options.output)
+		finished <- collectErr
 		g.mutex.Lock()
-		g.stdErrOut, collectErr = g.collectOutput(commandStderr, options.print, options.output)
+		g.stdErrOut = stdErr
 		g.mutex.Unlock()
-		finished <- collectErr
 	}()
 
 	collectErr1 := <-finished
@@ -161,10 +164,18 @@ func (g *genericCommand) collectOutput(output io.Reader, print bool, out chan st
 func (g *genericCommand) GetError() error { return g.errorMessage }
 
 // GetStdOut returns the complete output of the command
-func (g *genericCommand) GetStdOut() []string { return g.stdOut }
+func (g *genericCommand) GetStdOut() []string {
+	g.mutex.Lock()
+	defer g.mutex.Unlock()
+	return g.stdOut
+}
 
 // GetStdErrOut returns the complete StdErr of the command
-func (g *genericCommand) GetStdErrOut() []string { return g.stdErrOut }
+func (g *genericCommand) GetStdErrOut() []string {
+	g.mutex.Lock()
+	defer g.mutex.Unlock()
+	return g.stdErrOut
+}
 
 // GetWebhookData returns all objects that should get marshalled to json and
 // sent to the webhook endpoint. Returns nil by default.

restic/listsnapshots.go

@@ -33,15 +33,15 @@ func (l *ListSnapshotsStruct) ListSnapshots(last bool) []Snapshot {
 
 	l.genericCommand.exec(args, commandOptions{print: false})
 	fmt.Printf("Listing snapshots\n")
-	if len(l.stdErrOut) > 1 && strings.Contains(l.stdErrOut[1], "following location?") {
+	if len(l.GetStdErrOut()) > 1 && strings.Contains(l.GetStdErrOut()[1], "following location?") {
 		l.errorMessage = errors.New(notInitialisedError)
 		return nil
 	}
 	snaps := make([]Snapshot, 0)
-	output := strings.Join(l.stdOut, "\n")
+	output := strings.Join(l.GetStdOut(), "\n")
 	err := json.Unmarshal([]byte(output), &snaps)
 	if err != nil {
-		fmt.Printf("Error listing snapshots:\n%v\n%v\n%v\n", err, output, strings.Join(l.stdErrOut, "\n"))
+		fmt.Printf("Error listing snapshots:\n%v\n%v\n%v\n", err, output, strings.Join(l.GetStdErrOut(), "\n"))
 		l.errorMessage = err
 		return nil
 	}