Fix data races

Signed-off-by: Alex Leong <[email protected]>

controller/api/destination/federated_service_watcher.go

@@ -27,6 +27,8 @@ type federatedServiceWatcher struct {
 	localEndpoints *watcher.EndpointsWatcher
 
 	log *logging.Entry
+
+	sync.Mutex
 }
 
 type remoteDiscoveryID struct {
@@ -109,10 +111,14 @@ func (fsw *federatedServiceWatcher) Subscribe(
 	endStream chan struct{},
 ) error {
 	id := watcher.ServiceID{Namespace: namespace, Name: service}
+	fsw.Lock()
 	if federatedService, ok := fsw.services[id]; ok {
+		fsw.Unlock()
 		fsw.log.Debugf("Subscribing to federated service %s/%s", namespace, service)
 		federatedService.subscribe(port, nodeName, instanceID, stream, endStream)
 		return nil
+	} else {
+		fsw.Unlock()
 	}
 	return fmt.Errorf("service %s/%s is not a federated service", namespace, service)
 }
@@ -123,9 +129,13 @@ func (fsw *federatedServiceWatcher) Unsubscribe(
 	stream pb.Destination_GetServer,
 ) {
 	id := watcher.ServiceID{Namespace: namespace, Name: service}
+	fsw.Lock()
 	if federatedService, ok := fsw.services[id]; ok {
+		fsw.Unlock()
 		fsw.log.Debugf("Unsubscribing from federated service %s/%s", namespace, service)
 		federatedService.unsubscribe(stream)
+	} else {
+		fsw.Unlock()
 	}
 }
 
@@ -137,20 +147,27 @@ func (fsw *federatedServiceWatcher) addService(obj interface{}) {
 	}
 
 	if isFederatedService(service) {
+		fsw.Lock()
 		if federatedService, ok := fsw.services[id]; ok {
+			fsw.Unlock()
 			fsw.log.Debugf("Updating federated service %s/%s", service.Namespace, service.Name)
 			federatedService.update(service)
 		} else {
 			fsw.log.Debugf("Adding federated service %s/%s", service.Namespace, service.Name)
 			federatedService = fsw.newFederatedService(service)
 			fsw.services[id] = federatedService
+			fsw.Unlock()
 			federatedService.update(service)
 		}
 	} else {
+		fsw.Lock()
 		if federatedService, ok := fsw.services[id]; ok {
+			delete(fsw.services, id)
+			fsw.Unlock()
 			fsw.log.Debugf("Service %s/%s is no longer a federated service", service.Namespace, service.Name)
 			federatedService.delete()
-			delete(fsw.services, id)
+		} else {
+			fsw.Unlock()
 		}
 	}
 }
@@ -268,6 +285,9 @@ func (fs *federatedService) subscribe(
 	stream pb.Destination_GetServer,
 	endStream chan struct{},
 ) {
+	fs.Lock()
+	defer fs.Unlock()
+
 	syncStream := newSyncronizedGetStream(stream, fs.log)
 	syncStream.Start()
 
@@ -287,8 +307,6 @@ func (fs *federatedService) subscribe(
 		fs.localDiscoverySubscribe(&subscriber, fs.localDiscovery)
 	}
 
-	fs.Lock()
-	defer fs.Unlock()
 	fs.subscribers = append(fs.subscribers, subscriber)
 }