Fix router panic when trying to update route (#811)

router/httpTriggers.go

@@ -49,6 +49,7 @@ type HTTPTriggerSet struct {
 	functions                  []crd.Function
 	funcStore                  k8sCache.Store
 	funcController             k8sCache.Controller
+	updateRouterRequestChannel chan struct{}
 
 	tsRoundTripperParams *tsRoundTripperParams
 }
@@ -62,6 +63,7 @@ func makeHTTPTriggerSet(fmap *functionServiceMap, fissionClient *crd.FissionClie
 		kubeClient:                 kubeClient,
 		executor:                   executor,
 		crdClient:                  crdClient,
+		updateRouterRequestChannel: make(chan struct{}),
 		tsRoundTripperParams:       params,
 	}
 	var tStore, fnStore k8sCache.Store
@@ -87,6 +89,7 @@ func (ts *HTTPTriggerSet) subscribeRouter(ctx context.Context, mr *mutableRouter
 		log.Printf("Skipping continuous trigger updates")
 		return
 	}
+	go ts.updateRouter()
 	go ts.runWatcher(ctx, ts.funcController)
 	go ts.runWatcher(ctx, ts.triggerController)
 }
@@ -192,6 +195,11 @@ func (ts *HTTPTriggerSet) initTriggerController() (k8sCache.Store, k8sCache.Cont
 			UpdateFunc: func(oldObj interface{}, newObj interface{}) {
 				oldTrigger := oldObj.(*crd.HTTPTrigger)
 				newTrigger := newObj.(*crd.HTTPTrigger)
+
+				if oldTrigger.Metadata.ResourceVersion == newTrigger.Metadata.ResourceVersion {
+					return
+				}
+
 				go updateIngress(oldTrigger, newTrigger, ts.kubeClient)
 				ts.syncTriggers()
 			},
@@ -211,7 +219,13 @@ func (ts *HTTPTriggerSet) initFunctionController() (k8sCache.Store, k8sCache.Con
 				ts.syncTriggers()
 			},
 			UpdateFunc: func(oldObj interface{}, newObj interface{}) {
+				oldFn := oldObj.(*crd.Function)
 				fn := newObj.(*crd.Function)
+
+				if oldFn.Metadata.ResourceVersion == fn.Metadata.ResourceVersion {
+					return
+				}
+
 				// update resolver function reference cache
 				for key, rr := range ts.resolver.copy() {
 					if key.functionReference.Name == fn.Metadata.Name &&
@@ -236,6 +250,11 @@ func (ts *HTTPTriggerSet) runWatcher(ctx context.Context, controller k8sCache.Co
 }
 
 func (ts *HTTPTriggerSet) syncTriggers() {
+	ts.updateRouterRequestChannel <- struct{}{}
+}
+
+func (ts *HTTPTriggerSet) updateRouter() {
+	for range ts.updateRouterRequestChannel {
 		// get triggers
 		latestTriggers := ts.triggerStore.List()
 		triggers := make([]crd.HTTPTrigger, len(latestTriggers))
@@ -255,3 +274,4 @@ func (ts *HTTPTriggerSet) syncTriggers() {
 		// make a new router and use it
 		ts.mutableRouter.updateRouter(ts.getRouter())
 	}
+}