Clone from snapshot annotation

Add cloneFromSnapshot annotation and functionality

Author: jharrod

frontend/csi/controller_helpers/kubernetes/config.go

@@ -47,6 +47,7 @@ const (
 	AnnBlockSize            = annPrefix + "/blockSize"
 	AnnFileSystem           = annPrefix + "/fileSystem"
 	AnnCloneFromPVC         = annPrefix + "/cloneFromPVC"
+	AnnCloneFromSnapshot    = annPrefix + "/cloneFromSnapshot"
 	AnnSplitOnClone         = annPrefix + "/splitOnClone"
 	AnnNotManaged           = annPrefix + "/notManaged"
 	AnnImportOriginalName   = annPrefix + "/importOriginalName"

frontend/csi/controller_helpers/kubernetes/helper.go

@@ -92,11 +92,28 @@ func (h *helper) GetVolumeConfig(
 	annotations := processPVCAnnotations(pvc, fsType)
 	volumeConfig := getVolumeConfig(ctx, pvc, pvName, pvcSize, annotations, sc, requisiteTopology, preferredTopology)
 
+	// Get clone annotations
+	sourceSnapshotName := getAnnotation(annotations, AnnCloneFromSnapshot)
+	sourcePVCName := getAnnotation(annotations, AnnCloneFromPVC)
+
 	// Check if we're cloning a PVC, and if so, do some further validation
-	if cloneSourcePVName, err := h.getCloneSourceInfo(ctx, pvc); err != nil {
-		return nil, err
-	} else if cloneSourcePVName != "" {
-		volumeConfig.CloneSourceVolume = cloneSourcePVName
+	if sourcePVCName != "" && sourceSnapshotName == "" {
+		if cloneSourcePVName, err := h.getCloneSourceInfo(ctx, pvc); err != nil {
+			return nil, err
+		} else if cloneSourcePVName != "" {
+			volumeConfig.CloneSourceVolume = cloneSourcePVName
+		}
+	}
+
+	// Check if we're cloning from a snapshot, and if so, do some further validation
+	if sourceSnapshotName != "" {
+		cloneSourceVolume, cloneSourceSnapshot, err := h.getSnapshotCloneSourceInfo(ctx, pvc)
+		if err != nil {
+			return nil, err
+		} else if cloneSourceVolume != "" && cloneSourceSnapshot != "" {
+			volumeConfig.CloneSourceVolume = cloneSourceVolume
+			volumeConfig.CloneSourceSnapshot = cloneSourceSnapshot
+		}
 	}
 
 	// Check if we're importing a volume and do some further validation
@@ -276,8 +293,73 @@ func (h *helper) getStorageClass(ctx context.Context, name string) (*k8sstoragev
 	return sc, nil
 }
 
+// getSnapshotCloneSourceInfo accepts the PVC of a volume being provisioned by CSI and inspects it
+// for the annotations indicating a snapshot clone operation (of which CSI is unaware).
+// The method completes several checks on the source snapshot, and PVC if provided, and returns the
+// name of the source PV and snapshot as needed by Trident to clone a volume.
+func (h *helper) getSnapshotCloneSourceInfo(
+	ctx context.Context, clonePVC *v1.PersistentVolumeClaim,
+) (string, string, error) {
+	// Check if this is a snapshot clone operation
+	annotations := processPVCAnnotations(clonePVC, "")
+	sourceSnapshotName := getAnnotation(annotations, AnnCloneFromSnapshot)
+	if sourceSnapshotName == "" {
+		return "", "", fmt.Errorf("annotation 'cloneFromSnapshot' is empty")
+	}
+
+	// Get the VolumeSnapshot
+	snapshot, err := h.getVolumeSnapshot(ctx, sourceSnapshotName, clonePVC.Namespace)
+	if err != nil {
+		return "", "", err
+	}
+
+	// If the clone from PVC annotation is also set, ensure it matches the snapshot
+	sourcePVCName := getAnnotation(annotations, AnnCloneFromPVC)
+	if sourcePVCName != "" {
+		snapSourcePVC := snapshot.Spec.Source.PersistentVolumeClaimName
+		if snapSourcePVC == nil {
+			return "", "", fmt.Errorf("cannot verify clone source PVC for snapshot '%s', "+
+				"PersistentVolumeClaimName is not set in the snapshot spec", sourceSnapshotName)
+		}
+		if sourcePVCName != *snapSourcePVC {
+			return "", "", fmt.Errorf("clone source snapshot '%s' does not originate from the given source "+
+				"PVC '%s'", sourceSnapshotName, sourcePVCName)
+		}
+	}
+
+	// Ensure the VolumeSnapshot is ready to use
+	if snapshot.Status.ReadyToUse == nil || !*snapshot.Status.ReadyToUse {
+		return "", "", fmt.Errorf("snapshot '%s' is not ready to use", snapshot.Name)
+	}
+
+	snapshotContent, err := h.getSnapshotContentFromSnapshot(ctx, snapshot)
+	if err != nil {
+		Logc(ctx).WithFields(LogFields{
+			"sourceSnapshotName": sourceSnapshotName,
+		}).Errorf("Clone source snapshot content not found: %v", err)
+		return "", "", err
+	}
+
+	// Ensure the VolumeSnapshotContent is ready to use
+	if snapshotContent.Status.ReadyToUse == nil || !*snapshotContent.Status.ReadyToUse {
+		return "", "", fmt.Errorf("volumeSnapshotContent '%s' is not ready to use", snapshotContent.Name)
+	}
+
+	if snapshotContent.Status.SnapshotHandle == nil {
+		return "", "", fmt.Errorf("volumeSnapshotContent '%s' does not have a snapshot handle",
+			snapshotContent.Name)
+	}
+
+	volumeName, snapshotName, err := storage.ParseSnapshotID(*snapshotContent.Status.SnapshotHandle)
+	if err != nil {
+		return "", "", err
+	}
+
+	return volumeName, snapshotName, nil
+}
+
 // getCloneSourceInfo accepts the PVC of a volume being provisioned by CSI and inspects it
-// for the annotations indicating a clone operation (of which CSI is unaware). If a clone is
+// for the annotations indicating a PVC clone operation (of which CSI is unaware). If a clone is
 // being created, the method completes several checks on the source PVC/PV and returns the
 // name of the source PV as needed by Trident to clone a volume as well as an optional
 // snapshot name (also potentially unknown to CSI).  Note that these legacy clone annotations
@@ -287,7 +369,7 @@ func (h *helper) getCloneSourceInfo(ctx context.Context, clonePVC *v1.Persistent
 	annotations := processPVCAnnotations(clonePVC, "")
 	sourcePVCName := getAnnotation(annotations, AnnCloneFromPVC)
 	if sourcePVCName == "" {
-		return "", nil
+		return "", fmt.Errorf("annotation 'cloneFromPVC' is empty")
 	}
 
 	// Check that the source PVC is in the same namespace.
@@ -476,6 +558,49 @@ func (h *helper) getSnapshotContentByName(ctx context.Context, name string) (*vs
 	return vsc, nil
 }
 
+// getVolumeSnapshot returns a VolumeSnapshot if it exists.
+func (h *helper) getVolumeSnapshot(
+	ctx context.Context, name, namespace string,
+) (*vsv1.VolumeSnapshot, error) {
+	fields := LogFields{"snapshotName": name, "namespace": namespace}
+	Logc(ctx).WithFields(fields).Trace(">>>> getVolumeSnapshot")
+	defer Logc(ctx).WithFields(fields).Trace("<<<< getVolumeSnapshot")
+
+	// Get the VolumeSnapshot
+	snapshot, err := h.snapClient.SnapshotV1().VolumeSnapshots(namespace).Get(ctx, name, getOpts)
+	if err != nil {
+		statusErr, ok := err.(*apierrors.StatusError)
+		if ok && statusErr.Status().Reason == metav1.StatusReasonNotFound {
+			return nil, errors.NotFoundError("snapshot %s not found; %v", name, statusErr)
+		}
+		return nil, err
+	}
+	return snapshot, nil
+}
+
+// getSnapshotContentBySnapshotName returns the VolumeSnapshotContent referenced by a VolumeSnapshot
+func (h *helper) getSnapshotContentFromSnapshot(
+	ctx context.Context, snapshot *vsv1.VolumeSnapshot,
+) (*vsv1.VolumeSnapshotContent, error) {
+	fields := LogFields{"snapshotName": snapshot.Name}
+	Logc(ctx).WithFields(fields).Trace(">>>> getSnapshotContentFromSnapshot")
+	defer Logc(ctx).WithFields(fields).Trace("<<<< getSnapshotContentFromSnapshot")
+
+	// Extract the VolumeSnapshotContent name from the VolumeSnapshot status
+	snapshotContentName := snapshot.Status.BoundVolumeSnapshotContentName
+	if snapshotContentName == nil || *snapshotContentName == "" {
+		return nil, errors.NotFoundError("boundVolumeSnapshotContentName not found for snapshot %s", snapshot.Name)
+	}
+
+	// Get the VolumeSnapshotContent
+	vsc, err := h.getSnapshotContentByName(ctx, *snapshotContentName)
+	if err != nil {
+		return nil, err
+	}
+
+	return vsc, nil
+}
+
 // getSnapshotInternalNameFromAnnotation gets the snapshotInternalName from an annotation on a VolumeSnapshotContent
 // for snapshot import.
 func (h *helper) getSnapshotInternalNameFromAnnotation(