Ensure the broker also expires registry entries

broker/http_broker.go

@@ -62,6 +62,8 @@ type httpPublication struct {
 var (
 	DefaultSubPath   = "/_sub"
 	broadcastVersion = "ff.http.broadcast"
+	registerTTL      = time.Minute
+	registerInterval = time.Second * 30
 )
 
 func init() {
@@ -148,6 +150,44 @@ func (h *httpSubscriber) Unsubscribe() error {
 	return nil
 }
 
+func (h *httpBroker) run(l net.Listener) {
+	t := time.NewTicker(registerInterval)
+	defer t.Stop()
+
+	for {
+		select {
+		// heartbeat for each subscriber
+		case <-t.C:
+			h.RLock()
+			for _, subs := range h.subscribers {
+				for _, sub := range subs {
+					h.r.Register(sub.svc, registry.RegisterTTL(registerTTL))
+				}
+			}
+			h.RUnlock()
+		// received exit signal
+		case ch := <-h.exit:
+			ch <- l.Close()
+			h.Lock()
+			h.running = false
+			h.Unlock()
+			return
+		// unsubscribe subscriber
+		case subscriber := <-h.unsubscribe:
+			h.Lock()
+			var subscribers []*httpSubscriber
+			for _, sub := range h.subscribers[subscriber.topic] {
+				if sub.id == subscriber.id {
+					h.r.Deregister(sub.svc)
+				}
+				subscribers = append(subscribers, sub)
+			}
+			h.subscribers[subscriber.topic] = subscribers
+			h.Unlock()
+		}
+	}
+}
+
 func (h *httpBroker) start() error {
 	h.Lock()
 	defer h.Unlock()
@@ -181,39 +221,25 @@ func (h *httpBroker) start() error {
 	h.address = l.Addr().String()
 
 	go http.Serve(l, h)
-
-	go func() {
-		for {
-			select {
-			case ch := <-h.exit:
-				ch <- l.Close()
-				h.Lock()
-				h.running = false
-				h.Unlock()
-				return
-			case subscriber := <-h.unsubscribe:
-				h.Lock()
-				var subscribers []*httpSubscriber
-				for _, sub := range h.subscribers[subscriber.topic] {
-					if sub.id == subscriber.id {
-						h.r.Deregister(sub.svc)
-					}
-					subscribers = append(subscribers, sub)
-				}
-				h.subscribers[subscriber.topic] = subscribers
-				h.Unlock()
-			}
-		}
-	}()
+	go h.run(l)
 
 	h.running = true
 	return nil
 }
 
 func (h *httpBroker) stop() error {
+	h.Lock()
+	defer h.Unlock()
+
+	if !h.running {
+		return nil
+	}
+
 	ch := make(chan error)
 	h.exit <- ch
-	return <-ch
+	err := <-ch
+	h.running = false
+	return err
 }
 
 func (h *httpBroker) ServeHTTP(w http.ResponseWriter, req *http.Request) {