Use common controller/store for httpTriggerSet and functionReferenceResolver (#390)

This fixes a bug where functionReferenceResolver returned out-of-date function metadata and caused the router to proxy requests to old function pods.

It also uses the go context package to shutdown the controller when the router is shutting down.

router/router.go

@@ -40,6 +40,7 @@ Its job is to:
 package router
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"net/http"
@@ -57,15 +58,15 @@ import (
 
 // request url ---[trigger]---> Function(name, deployment) ----[deployment]----> Function(name, uid) ----[pool mgr]---> k8s service url
 
-func router(httpTriggerSet *HTTPTriggerSet) *mutableRouter {
+func router(ctx context.Context, httpTriggerSet *HTTPTriggerSet, resolver *functionReferenceResolver) *mutableRouter {
 	muxRouter := mux.NewRouter()
 	mr := NewMutableRouter(muxRouter)
-	httpTriggerSet.subscribeRouter(mr)
+	httpTriggerSet.subscribeRouter(ctx, mr, resolver)
 	return mr
 }
 
-func serve(port int, httpTriggerSet *HTTPTriggerSet) {
-	mr := router(httpTriggerSet)
+func serve(ctx context.Context, port int, httpTriggerSet *HTTPTriggerSet, resolver *functionReferenceResolver) {
+	mr := router(ctx, httpTriggerSet, resolver)
 	url := fmt.Sprintf(":%v", port)
 	http.ListenAndServe(url, handlers.LoggingHandler(os.Stdout, mr))
 }
@@ -79,12 +80,10 @@ func Start(port int, poolmgrUrl string) {
 	}
 	restClient := fissionClient.GetCrdClient()
 	poolmgr := poolmgrClient.MakeClient(poolmgrUrl)
-	resolver := makeFunctionReferenceResolver(fissionClient)
-	resolver.Sync(restClient)
-	defer func() {
-		resolver.Stop()
-	}()
-	triggers := makeHTTPTriggerSet(fmap, fissionClient, poolmgr, resolver, restClient)
+	triggers, _, fnStore := makeHTTPTriggerSet(fmap, fissionClient, poolmgr, restClient)
+	resolver := makeFunctionReferenceResolver(fnStore)
 	log.Printf("Starting router at port %v\n", port)
-	serve(port, triggers)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	serve(ctx, port, triggers, resolver)
 }