CNI async delete after ReleaseIPAddress (#2232)

add second check for releaseIP failure

Co-authored-by: Quang Nguyen <[email protected]>

Author: camrynl

cni/network/invoker_cns.go

@@ -279,6 +279,7 @@ func setHostOptions(ncSubnetPrefix *net.IPNet, options map[string]interface{}, i
 
 // Delete calls into the releaseipconfiguration API in CNS
 func (invoker *CNSIPAMInvoker) Delete(address *net.IPNet, nwCfg *cni.NetworkConfig, args *cniSkel.CmdArgs, _ map[string]interface{}) error { //nolint
+	var connectionErr *cnscli.ConnectionFailureErr
 	// Parse Pod arguments.
 	podInfo := cns.KubernetesPodInfo{
 		PodName:      invoker.podName,
@@ -319,16 +320,21 @@ func (invoker *CNSIPAMInvoker) Delete(address *net.IPNet, nwCfg *cni.NetworkConf
 			}
 
 			if err = invoker.cnsClient.ReleaseIPAddress(context.TODO(), ipConfig); err != nil {
-				// if the old API fails as well then we just return the error
-
-				logger.Error("Failed to release IP address from CNS using ReleaseIPAddress ",
-					zap.String("infracontainerid", ipConfigs.InfraContainerID),
-					zap.Error(err))
-
-				return errors.Wrap(err, fmt.Sprintf("failed to release IP %v using ReleaseIPAddress with err ", ipConfig.DesiredIPAddress)+"%w")
+				if errors.As(err, &connectionErr) {
+					addErr := fsnotify.AddFile(ipConfigs.PodInterfaceID, args.ContainerID, watcherPath)
+					if addErr != nil {
+						logger.Error("Failed to add file to watcher", zap.String("podInterfaceID", ipConfigs.PodInterfaceID), zap.String("containerID", args.ContainerID), zap.Error(addErr))
+						return errors.Wrap(addErr, fmt.Sprintf("failed to add file to watcher with containerID %s and podInterfaceID %s", args.ContainerID, ipConfigs.PodInterfaceID))
+					}
+				} else {
+					logger.Error("Failed to release IP address from CNS using ReleaseIPAddress ",
+						zap.String("infracontainerid", ipConfigs.InfraContainerID),
+						zap.Error(err))
+
+					return errors.Wrap(err, fmt.Sprintf("failed to release IP %v using ReleaseIPAddress with err ", ipConfig.DesiredIPAddress)+"%w")
+				}
 			}
 		} else {
-			var connectionErr *cnscli.ConnectionFailureErr
 			if errors.As(err, &connectionErr) {
 				addErr := fsnotify.AddFile(ipConfigs.PodInterfaceID, args.ContainerID, watcherPath)
 				if addErr != nil {