Enabling multi-tenancy for fission objects. (#655)

This feature allows creation of fission objects in different namespaces, in addition to retaining the existing behavior of creating fission objects in default namespace if user doesnt provide one. 
It also removes cluster admin roles for fission-fetcher and fission-builder Service Accounts and grants them only those privileges that they need.

executor/poolmgr/gpm.go

@@ -52,8 +52,11 @@ type (
 		instanceId     string
 		requestChannel chan *request
 
-		enableIstio          bool
-		istioServiceRegister k8sCache.Controller
+		enableIstio    bool
+		funcStore      k8sCache.Store
+		funcController k8sCache.Controller
+		pkgStore       k8sCache.Store
+		pkgController  k8sCache.Controller
 	}
 	request struct {
 		requestType
@@ -92,20 +95,19 @@ func MakeGenericPoolManager(
 			log.Println("Failed to parse ENABLE_ISTIO")
 		}
 		gpm.enableIstio = istio
-
-		if gpm.enableIstio {
-			gpm.istioServiceRegister = makeFuncIstioServiceRegister(
-				gpm.fissionClient.GetCrdClient(), gpm.kubernetesClient, functionNamespace)
-		}
 	}
 
+	gpm.funcStore, gpm.funcController = gpm.makeFuncController(
+		gpm.fissionClient, gpm.kubernetesClient, gpm.namespace, gpm.enableIstio)
+
+	gpm.pkgStore, gpm.pkgController = gpm.makePkgController(gpm.fissionClient, gpm.kubernetesClient, gpm.namespace)
+
 	return gpm
 }
 
 func (gpm *GenericPoolManager) Run(ctx context.Context) {
-	if gpm.enableIstio && gpm.istioServiceRegister != nil {
-		go gpm.istioServiceRegister.Run(ctx.Done())
-	}
+	go gpm.funcController.Run(ctx.Done())
+	go gpm.pkgController.Run(ctx.Done())
 }
 
 func (gpm *GenericPoolManager) service() {
@@ -113,6 +115,7 @@ func (gpm *GenericPoolManager) service() {
 		req := <-gpm.requestChannel
 		switch req.requestType {
 		case GET_POOL:
+			// just because they are missing in the cache, we end up creating another duplicate pool.
 			var err error
 			pool, ok := gpm.pools[crd.CacheKey(&req.env.Metadata)]
 			if !ok {
@@ -122,9 +125,16 @@ func (gpm *GenericPoolManager) service() {
 					poolsize = 1
 				}
 
+				// To support backward compatibility, if envs are created in default ns, we go ahead
+				// and create pools in fission-function ns as earlier.
+				ns := gpm.namespace
+				if req.env.Metadata.Namespace != metav1.NamespaceDefault {
+					ns = req.env.Metadata.Namespace
+				}
+
 				pool, err = MakeGenericPool(
 					gpm.fissionClient, gpm.kubernetesClient, req.env, poolsize,
-					gpm.namespace, gpm.fsCache, gpm.instanceId, gpm.enableIstio)
+					ns, gpm.namespace, gpm.fsCache, gpm.instanceId, gpm.enableIstio)
 				if err != nil {
 					req.responseChannel <- &response{error: err}
 					continue
@@ -133,15 +143,12 @@ func (gpm *GenericPoolManager) service() {
 			}
 			req.responseChannel <- &response{pool: pool}
 		case CLEANUP_POOLS:
-			latestEnvSet := make(map[string]bool)
 			latestEnvPoolsize := make(map[string]int)
 			for _, env := range req.envList {
-				latestEnvSet[crd.CacheKey(&env.Metadata)] = true
 				latestEnvPoolsize[crd.CacheKey(&env.Metadata)] = int(gpm.getEnvPoolsize(&env))
 			}
 			for key, pool := range gpm.pools {
-				_, ok := latestEnvSet[key]
-				poolsize := latestEnvPoolsize[key]
+				poolsize, ok := latestEnvPoolsize[key]
 				if !ok || poolsize == 0 {
 					// Env no longer exists or pool size changed to zero