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/executor.go

@@ -70,6 +70,7 @@ func MakeExecutor(gpm *poolmgr.GenericPoolManager, ndm *newdeploy.NewDeploy, fis
 		fsCreateWg:  make(map[string]*sync.WaitGroup),
 	}
 	go executor.serveCreateFuncServices()
+
 	return executor
 }
 
@@ -127,7 +128,6 @@ func (executor *Executor) getFunctionExecutorType(meta *metav1.ObjectMeta) (fiss
 		return "", err
 	}
 	return fn.Spec.InvokeStrategy.ExecutionStrategy.ExecutorType, nil
-
 }
 
 func (executor *Executor) createServiceForFunction(meta *metav1.ObjectMeta) (*fscache.FuncSvc, error) {
@@ -211,9 +211,9 @@ func serveMetric() {
 	log.Fatal(http.ListenAndServe(metricAddr, nil))
 }
 
-// StartExecutor Starts executor and the backend components that executor uses such as Poolmgr,
-// deploymgr and potential future backends
-func StartExecutor(fissionNamespace string, functionNamespace string, port int) error {
+// StartExecutor Starts executor and the executor components such as Poolmgr,
+// deploymgr and potential future executor types
+func StartExecutor(fissionNamespace string, functionNamespace string, envBuilderNamespace string, port int) error {
 	// setup a signal handler for SIGTERM
 	fission.SetupStackTraceHandler()
 
@@ -235,6 +235,7 @@ func StartExecutor(fissionNamespace string, functionNamespace string, port int)
 	poolID := strings.ToLower(uniuri.NewLen(8))
 	cleanupObjects(kubernetesClient, functionNamespace, poolID)
 	go idleObjectReaper(kubernetesClient, fissionClient, fsCache, time.Minute*2)
+	go cleanupRoleBindings(kubernetesClient, fissionClient, functionNamespace, envBuilderNamespace, time.Minute*30)
 
 	gpm := poolmgr.MakeGenericPoolManager(
 		fissionClient, kubernetesClient,