Allow to tap multiple function services at one time (#1434)

The router taps function service one by one which is inefficient and
increases the burden of executor. This PR aggregates all requests into
one to solve the problem mentioned above.

pkg/router/httpTriggers.go

@@ -142,7 +142,7 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 			fmap:                     ts.functionServiceMap,
 			executor:                 ts.executor,
 			httpTrigger:              &trigger,
-			functionMetadataMap:      rr.functionMetadataMap,
+			functionMap:              rr.functionMap,
 			fnWeightDistributionList: rr.functionWtDistributionList,
 			tsRoundTripperParams:     ts.tsRoundTripperParams,
 			isDebugEnv:               ts.isDebugEnv,
@@ -158,8 +158,8 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 		// deployment. For more details, please check "handler" function of functionHandler.
 
 		if rr.resolveResultType == resolveResultSingleFunction {
-			for _, metadata := range fh.functionMetadataMap {
-				fh.function = metadata
+			for _, fn := range fh.functionMap {
+				fh.function = fn
 			}
 		}
 
@@ -185,20 +185,19 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 
 	// Internal triggers for each function by name. Non-http
 	// triggers route into these.
-	for _, function := range ts.functions {
-		m := function.Metadata
-
+	for i := range ts.functions {
+		fn := ts.functions[i]
 		fh := &functionHandler{
-			logger:                 ts.logger.Named(m.Name),
+			logger:                 ts.logger.Named(fn.Metadata.Name),
 			fmap:                   ts.functionServiceMap,
-			function:               &m,
+			function:               &fn,
 			executor:               ts.executor,
 			tsRoundTripperParams:   ts.tsRoundTripperParams,
 			isDebugEnv:             ts.isDebugEnv,
 			svcAddrUpdateThrottler: ts.svcAddrUpdateThrottler,
 			functionTimeoutMap:     fnTimeoutMap,
 		}
-		muxRouter.HandleFunc(utils.UrlForFunction(function.Metadata.Name, function.Metadata.Namespace), fh.handler)
+		muxRouter.HandleFunc(utils.UrlForFunction(fn.Metadata.Name, fn.Metadata.Namespace), fh.handler)
 	}
 
 	// Healthz endpoint for the router.
@@ -263,8 +262,8 @@ func (ts *HTTPTriggerSet) initFunctionController() (k8sCache.Store, k8sCache.Con
 				// update resolver function reference cache
 				for key, rr := range ts.resolver.copy() {
 					if key.namespace == fn.Metadata.Namespace &&
-						rr.functionMetadataMap[fn.Metadata.Name] != nil &&
-						rr.functionMetadataMap[fn.Metadata.Name].ResourceVersion != fn.Metadata.ResourceVersion {
+						rr.functionMap[fn.Metadata.Name] != nil &&
+						rr.functionMap[fn.Metadata.Name].Metadata.ResourceVersion != fn.Metadata.ResourceVersion {
 						// invalidate resolver cache
 						ts.logger.Debug("invalidating resolver cache")
 						err := ts.resolver.delete(key.namespace, key.triggerName, key.triggerResourceVersion)