Skip to call device-info related function if not required

The case withot DeviceInfo/ResourceName, we could skip functions
related to device info. This change skips to call these functions
if delegates does not have DeviceInfo/ResourceName.

pkg/multus/multus.go

@@ -584,7 +584,7 @@ func CmdAdd(args *skel.CmdArgs, exec invoke.Exec, kubeClient *k8s.ClientInfo) (c
 	for idx, delegate := range n.Delegates {
 		ifName := getIfname(delegate, args.IfName, idx)
 		rt, cniDeviceInfoPath := types.CreateCNIRuntimeConf(args, k8sArgs, ifName, n.RuntimeConfig, delegate)
-		if cniDeviceInfoPath != "" {
+		if cniDeviceInfoPath != "" && delegate.ResourceName != "" && delegate.DeviceID != "" {
 			err = nadutils.CopyDeviceInfoForCNIFromDP(cniDeviceInfoPath, delegate.ResourceName, delegate.DeviceID)
 			// Even if the filename is set, file may not be present. Ignore error,
 			// but log and in the future may need to filter on specific errors.

pkg/types/conf.go

@@ -188,13 +188,15 @@ func CreateCNIRuntimeConf(args *skel.CmdArgs, k8sArgs *K8sArgs, ifName string, r
 
 	if delegate != nil {
 		delegateRc = mergeCNIRuntimeConfig(rc, delegate)
-		if delegateRc.CNIDeviceInfoFile != "" {
-			logging.Debugf("Warning: Existing value of CNIDeviceInfoFile will be overwritten %s", delegateRc.CNIDeviceInfoFile)
+		if delegateRc.DeviceID != "" {
+			if delegateRc.CNIDeviceInfoFile != "" {
+				logging.Debugf("Warning: Existing value of CNIDeviceInfoFile will be overwritten %s", delegateRc.CNIDeviceInfoFile)
+			}
+			autoDeviceInfo := fmt.Sprintf("%s-%s_%s", delegate.Name, args.ContainerID, ifName)
+			delegateRc.CNIDeviceInfoFile = nadutils.GetCNIDeviceInfoPath(autoDeviceInfo)
+			cniDeviceInfoFile = delegateRc.CNIDeviceInfoFile
+			logging.Debugf("Adding auto-generated CNIDeviceInfoFile: %s", delegateRc.CNIDeviceInfoFile)
 		}
-		autoDeviceInfo := fmt.Sprintf("%s-%s_%s", delegate.Name, args.ContainerID, ifName)
-		delegateRc.CNIDeviceInfoFile = nadutils.GetCNIDeviceInfoPath(autoDeviceInfo)
-		cniDeviceInfoFile = delegateRc.CNIDeviceInfoFile
-		logging.Debugf("Adding auto-generated CNIDeviceInfoFile: %s", delegateRc.CNIDeviceInfoFile)
 	} else {
 		delegateRc = rc
 	}