Skip status update in CmdDel if getPod is failed

This change skips to update pod's network-status annotation
when getPod is failed at the beginning of CmdDel. If getPod is
failed, K8s api gets stucked in many cases, hence pod update
might be failed in most cases.

pkg/multus/multus.go

@@ -774,14 +774,14 @@ func CmdDel(args *skel.CmdArgs, exec invoke.Exec, kubeClient *k8s.ClientInfo) er
 		return err
 	}
 
-	netnsfound := true
+	skipStatusUpdate := false
 	netns, err := ns.GetNS(args.Netns)
 	if err != nil {
 		// if NetNs is passed down by the Cloud Orchestration Engine, or if it called multiple times
 		// so don't return an error if the device is already removed.
 		// https://github.com/kubernetes/kubernetes/issues/43014#issuecomment-287164444
 		_, ok := err.(ns.NSPathNotExistErr)
-		netnsfound = false
+		skipStatusUpdate = true
 		if ok {
 			logging.Debugf("CmdDel: WARNING netns may not exist, netns: %s, err: %s", args.Netns, err)
 		} else {
@@ -817,6 +817,8 @@ func CmdDel(args *skel.CmdArgs, exec invoke.Exec, kubeClient *k8s.ClientInfo) er
 	if err != nil {
 		// getPod may be failed but just do print error in its log and continue to delete
 		logging.Errorf("Multus: getPod failed: %v, but continue to delete", err)
+		// skip status update because k8s api seems to be stucked
+		skipStatusUpdate = true
 	}
 
 	// Read the cache to get delegates json for the pod
@@ -878,7 +880,7 @@ func CmdDel(args *skel.CmdArgs, exec invoke.Exec, kubeClient *k8s.ClientInfo) er
 
 	// unset the network status annotation in apiserver, only in case Multus as kubeconfig
 	if in.Kubeconfig != "" {
-		if netnsfound {
+		if !skipStatusUpdate {
 			if !types.CheckSystemNamespaces(string(k8sArgs.K8S_POD_NAMESPACE), in.SystemNamespaces) {
 				err := k8s.SetNetworkStatus(kubeClient, k8sArgs, nil, in)
 				if err != nil {
@@ -887,7 +889,7 @@ func CmdDel(args *skel.CmdArgs, exec invoke.Exec, kubeClient *k8s.ClientInfo) er
 				}
 			}
 		} else {
-			logging.Debugf("WARNING: Unset SetNetworkStatus skipped due to netns not found.")
+			logging.Debugf("WARNING: Unset SetNetworkStatus skipped")
 		}
 	}