Capture os signals to gracefully shutdown fission components (#2261)

- Currently, fission components don't handle shutdown signals.
So we don't get any to do the required cleanup before the fission process
exits. Adding signal capture process with cancelling context so
that all dependent processes stop working when the process gets term
signal.
- Set log level to error in otel shutdown function

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/executor/executor.go

@@ -261,7 +261,7 @@ func serveMetric(logger *zap.Logger) {
 
 // StartExecutor Starts executor and the executor components such as Poolmgr,
 // deploymgr and potential future executor types
-func StartExecutor(logger *zap.Logger, functionNamespace string, envBuilderNamespace string, port int, openTracingEnabled bool) error {
+func StartExecutor(ctx context.Context, logger *zap.Logger, functionNamespace string, envBuilderNamespace string, port int, openTracingEnabled bool) error {
 	fissionClient, kubernetesClient, _, metricsClient, err := crd.MakeFissionClient()
 	if err != nil {
 		return errors.Wrap(err, "failed to get kubernetes client")
@@ -324,7 +324,6 @@ func StartExecutor(logger *zap.Logger, functionNamespace string, envBuilderNames
 	}
 	cnmDeplInformer := cnmInformerFactory.Apps().V1().Deployments()
 	cnmSvcInformer := cnmInformerFactory.Core().V1().Services()
-	ctx := context.Background()
 	cnm, err := container.MakeContainer(
 		ctx, logger,
 		fissionClient, kubernetesClient,
@@ -379,7 +378,7 @@ func StartExecutor(logger *zap.Logger, functionNamespace string, envBuilderNames
 	if err != nil {
 		return err
 	}
-	go reaper.CleanupRoleBindings(logger, kubernetesClient, fissionClient, functionNamespace, envBuilderNamespace, time.Minute*30)
+	go reaper.CleanupRoleBindings(ctx, logger, kubernetesClient, fissionClient, functionNamespace, envBuilderNamespace, time.Minute*30)
 	go api.Serve(port, openTracingEnabled)
 	go serveMetric(logger)