util: add support for the nsenter

add support to run rbd map and mount -t
commands with the nsenter.

complete design of pod/multus network
is added here https://github.com/rook/rook/
blob/master/design/ceph/multus-network.md#csi-pods

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/rbd/nodeserver.go

@@ -332,6 +332,10 @@ func (ns *NodeServer) NodeStageVolume(
 	}
 	defer rv.Destroy()
 
+	rv.NetNamespaceFilePath, err = util.GetNetNamespaceFilePath(util.CsiConfigFile, rv.ClusterID)
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
 	if isHealer {
 		err = healerStageTransaction(ctx, cr, rv, stagingParentPath)
 		if err != nil {

internal/rbd/rbd_attach.go

@@ -457,8 +457,17 @@ func createPath(ctx context.Context, volOpt *rbdVolume, device string, cr *util.
 		mapArgs = append(mapArgs, "--read-only")
 	}
 
-	// Execute map
-	stdout, stderr, err := util.ExecCommand(ctx, cli, mapArgs...)
+	var (
+		stdout string
+		stderr string
+		err    error
+	)
+
+	if volOpt.NetNamespaceFilePath != "" {
+		stdout, stderr, err = util.ExecuteCommandWithNSEnter(ctx, volOpt.NetNamespaceFilePath, cli, mapArgs...)
+	} else {
+		stdout, stderr, err = util.ExecCommand(ctx, cli, mapArgs...)
+	}
 	if err != nil {
 		log.WarningLog(ctx, "rbd: map error %v, rbd output: %s", err, stderr)
 		// unmap rbd image if connection timeout

internal/rbd/rbd_util.go

@@ -156,6 +156,8 @@ type rbdVolume struct {
 	LogStrategy        string
 	VolName            string
 	MonValueFromSecret string
+	// Network namespace file path to execute nsenter command
+	NetNamespaceFilePath string
 	// RequestedVolSize has the size of the volume requested by the user and
 	// this value will not be updated when doing getImageInfo() on rbdVolume.
 	RequestedVolSize   int64