have waitForStartByIdent() return an error

proxy/proxy.go

@@ -359,11 +359,11 @@ func (proxy *Proxy) waitForStart(r *http.Request) error {
 }
 
 // If some other operation is waiting for a container to start, join in the wait
-func (proxy *Proxy) waitForStartByIdent(ident string) {
-	var ch chan struct{}
+func (proxy *Proxy) waitForStartByIdent(ident string) error {
+	var ch chan error
 	proxy.Lock()
 	for _, wait := range proxy.waiters {
-		if ident == wait.ident {
+		if ident == wait.ident && !wait.done {
 			ch = wait.ch
 			break
 		}
@@ -371,8 +371,9 @@ func (proxy *Proxy) waitForStartByIdent(ident string) {
 	proxy.Unlock()
 	if ch != nil {
 		Log.Debugf("Wait for start of container %s", ident)
-		<-ch
+		return <-ch
 	}
+	return nil
 }
 
 func (proxy *Proxy) ContainerDied(ident string) {
@@ -519,7 +520,9 @@ func (proxy *Proxy) updateContainerNetworkSettings(container jsonObject) error {
 		return err
 	}
 
-	proxy.waitForStartByIdent(containerID)
+	if err := proxy.waitForStartByIdent(containerID); err != nil {
+		return err
+	}
 	mac, ips, nets, err := weaveContainerIPs(containerID)
 	if err != nil || len(ips) == 0 {
 		return err