rbd: fill clusterID if its a migration nodestage request

the migration nodestage request does not carry the 'clusterID' in it
and only monitors are available with the volumeContext. The volume
context flag 'migration=true' and 'static=true' flags allow us to
fill 'clusterID' from the passed in monitors to the volume Context,so
that rest of the static operations on nodestage can be proceeded as we
do treat static volumes today.

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

internal/rbd/nodeserver.go

@@ -149,6 +149,25 @@ func healerStageTransaction(ctx context.Context, cr *util.Credentials, volOps *r
 	return nil
 }
 
+// getClusterIDFromMigrationVolume fills the clusterID for the passed in monitors.
+func getClusterIDFromMigrationVolume(parameters map[string]string) (string, error) {
+	var err error
+	var rclusterID string
+	mons := parameters["monitors"]
+	for _, m := range strings.Split(mons, ",") {
+		rclusterID, err = util.GetClusterIDFromMon(m)
+		if err != nil && !errors.Is(err, util.ErrMissingConfigForMonitor) {
+			return "", err
+		}
+
+		if rclusterID != "" {
+			return rclusterID, nil
+		}
+	}
+
+	return "", err
+}
+
 // populateRbdVol update the fields in rbdVolume struct based on the request it received.
 func populateRbdVol(
 	ctx context.Context,
@@ -188,6 +207,10 @@ func populateRbdVol(
 	// get rbd image name from the volume journal
 	// for static volumes, the image name is actually the volume ID itself
 	if isStaticVol {
+		if req.GetVolumeContext()[intreeMigrationKey] == intreeMigrationLabel {
+			// if migration static volume, use imageName as volID
+			volID = req.GetVolumeContext()["imageName"]
+		}
 		rv.RbdImageName = volID
 	} else {
 		var vi util.CSIIdentifier
@@ -268,6 +291,16 @@ func (ns *NodeServer) NodeStageVolume(
 	}
 	defer ns.VolumeLocks.Release(volID)
 
+	// Check this is a migration request because in that case, unlike other node stage requests
+	// it will be missing the clusterID, so fill it by fetching it from config file using mon.
+	if req.GetVolumeContext()[intreeMigrationKey] == intreeMigrationLabel && req.VolumeContext[util.ClusterIDKey] == "" {
+		cID, cErr := getClusterIDFromMigrationVolume(req.GetVolumeContext())
+		if cErr != nil {
+			return nil, status.Error(codes.Internal, cErr.Error())
+		}
+		req.VolumeContext[util.ClusterIDKey] = cID
+	}
+
 	stagingParentPath := req.GetStagingTargetPath()
 	stagingTargetPath := stagingParentPath + "/" + volID
 

internal/rbd/rbd_util.go

@@ -73,6 +73,10 @@ const (
 	// thick provisioned or thin provisioned.
 	thickProvisionMetaData = "true"
 	thinProvisionMetaData  = "false"
+
+	// these are the migration label key and value for parameters in volume context.
+	intreeMigrationKey   = "migration"
+	intreeMigrationLabel = "true"
 )
 
 // rbdImage contains common attributes and methods for the rbdVolume and