add config for disabling async delete

Signed-off-by: Tamilmani <tamanoha@microsoft.com>

Author: tamilmani1989

cni/netconfig.go

@@ -72,6 +72,7 @@ type NetworkConfig struct {
 	EnableExactMatchForPodName    bool            `json:"enableExactMatchForPodName,omitempty"`
 	DisableHairpinOnHostInterface bool            `json:"disableHairpinOnHostInterface,omitempty"`
 	DisableIPTableLock            bool            `json:"disableIPTableLock,omitempty"`
+	DisableAsyncDelete            bool            `json:"disableAsyncDelete,omitempty"`
 	CNSUrl                        string          `json:"cnsurl,omitempty"`
 	ExecutionMode                 string          `json:"executionMode,omitempty"`
 	IPAM                          IPAM            `json:"ipam,omitempty"`

cni/network/network.go

@@ -1079,7 +1079,7 @@ func (plugin *NetPlugin) Delete(args *cniSkel.CmdArgs) error {
 		epInfos, err = plugin.nm.GetEndpointState(networkID, args.ContainerID)
 		// if stateless CNI fail to get the endpoint from CNS for any reason other than  Endpoint Not found
 		if err != nil {
-			if errors.Is(err, network.ErrConnectionFailure) {
+			if errors.Is(err, network.ErrConnectionFailure) && !nwCfg.DisableAsyncDelete {
 				logger.Info("failed to connect to CNS", zap.String("containerID", args.ContainerID), zap.Error(err))
 				addErr := fsnotify.AddFile(args.ContainerID, args.ContainerID, watcherPath)
 				logger.Info("add containerid file for Asynch delete", zap.String("containerID", args.ContainerID), zap.Error(addErr))

network/manager.go

@@ -773,6 +773,7 @@ func (nm *networkManager) DeleteState(epInfos []*EndpointInfo) error {
 
 	if nm.IsStatelessCNIMode() {
 		for _, epInfo := range epInfos {
+			// this cleanup happens only for standalone swiftv2 to delete endpoint state from CNS.
 			if epInfo.NICType == cns.NodeNetworkInterfaceFrontendNIC || epInfo.NICType == cns.NodeNetworkInterfaceAccelnetFrontendNIC {
 				response, err := nm.CnsClient.DeleteEndpointState(context.TODO(), epInfo.EndpointID)
 				if err != nil {