rbd: VolumeGroupSnapshot support

internal/rbd/group_controller.go

@@ -0,0 +1,214 @@
+/*
+Copyright 2024 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rbd
+
+import (
+	"context"
+
+	"github.com/container-storage-interface/spec/lib/go/csi"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/ceph/ceph-csi/internal/rbd/types"
+	"github.com/ceph/ceph-csi/internal/util/log"
+)
+
+// CreateVolumeGroupSnapshot receives a list of volume handles and is requested
+// to create a list of snapshots that are created at the same time. This is
+// similar (although not exactly the same) to consistency groups.
+//
+// RBD has a limitation that an image can only belong to a single group. It is
+// therefore required to create a temporary group, add all images, create the
+// group snapshot and remove all images from the group again. This leaves the
+// group and its snapshot around, the group snapshot can be inspected to list
+// the snapshots of the images.
+func (cs *ControllerServer) CreateVolumeGroupSnapshot(
+	ctx context.Context,
+	req *csi.CreateVolumeGroupSnapshotRequest,
+) (*csi.CreateVolumeGroupSnapshotResponse, error) {
+	var (
+		err           error
+		vg            types.VolumeGroup
+		groupSnapshot types.VolumeGroupSnapshot
+
+		// the VG and VGS should not have the same name
+		vgName  = req.GetName() + "-vg" // stable temporary name
+		vgsName = req.GetName()
+	)
+
+	mgr := NewManager(cs.Driver.GetInstanceID(), req.GetParameters(), req.GetSecrets())
+	defer mgr.Destroy(ctx)
+
+	// resolve all volumes, free them later on
+	volumes := make([]types.Volume, len(req.GetSourceVolumeIds()))
+	defer func() {
+		for _, volume := range volumes {
+			if vg != nil {
+				// 'normal' cleanup, remove all images from the group
+				vgErr := vg.RemoveVolume(ctx, volume)
+				if vgErr != nil {
+					log.ErrorLog(
+						ctx,
+						"failed to remove volume %q from volume group %q: %v",
+						volume, vg, vgErr)
+				}
+			}
+
+			// free all allocated volumes
+			if volume != nil {
+				volume.Destroy(ctx)
+			}
+		}
+
+		if vg != nil {
+			// the VG should always be deleted, volumes can only belong to a single VG
+			log.DebugLog(ctx, "removing temporary volume group %q", vg)
+
+			vgErr := vg.Delete(ctx)
+			if vgErr != nil {
+				log.ErrorLog(ctx, "failed to remove temporary volume group %q: %v", vg, vgErr)
+			}
+
+			vg.Destroy(ctx)
+		}
+	}()
+	for i, id := range req.GetSourceVolumeIds() {
+		var vol types.Volume
+		vol, err = mgr.GetVolumeByID(ctx, id)
+		if err != nil {
+			return nil, status.Errorf(
+				codes.InvalidArgument,
+				"failed to find required volume %q for volume group snapshot %q: %s",
+				id,
+				vgsName,
+				err.Error())
+		}
+		volumes[i] = vol
+	}
+
+	log.DebugLog(ctx, "all %d Volumes for VolumeGroup %q have been found", len(volumes), vgsName)
+
+	groupSnapshot, err = mgr.GetVolumeGroupSnapshotByName(ctx, vgsName)
+	if groupSnapshot != nil {
+		csiVGS, csiErr := groupSnapshot.ToCSI(ctx)
+		if csiErr != nil {
+			return nil, status.Error(codes.Aborted, csiErr.Error())
+		}
+
+		return &csi.CreateVolumeGroupSnapshotResponse{
+			GroupSnapshot: csiVGS,
+		}, nil
+	}
+	if err != nil {
+		log.DebugLog(ctx, "need to create new volume group snapshot, "+
+			"failed to get existing one with name %q: %v", err)
+	}
+
+	// create a temporary VolumeGroup with a different name
+	vg, err = mgr.CreateVolumeGroup(ctx, vgName)
+	if err != nil {
+		return nil, status.Errorf(
+			codes.Internal,
+			"failed to create volume group %q: %s",
+			vgName,
+			err.Error())
+	}
+
+	log.DebugLog(ctx, "VolumeGroup %q has been created: %+v", vgName, vg)
+
+	// add images to the group
+	for _, volume := range volumes {
+		err = vg.AddVolume(ctx, volume)
+		if err != nil {
+			return nil, status.Error(codes.Aborted, err.Error())
+		}
+	}
+
+	groupSnapshot, err = mgr.CreateVolumeGroupSnapshot(ctx, vg, vgsName)
+	if err != nil {
+		return nil, status.Error(codes.Aborted, err.Error())
+	}
+	defer groupSnapshot.Destroy(ctx)
+
+	csiVGS, err := groupSnapshot.ToCSI(ctx)
+	if err != nil {
+		return nil, status.Error(codes.Aborted, err.Error())
+	}
+
+	return &csi.CreateVolumeGroupSnapshotResponse{
+		GroupSnapshot: csiVGS,
+	}, nil
+}
+
+func (cs *ControllerServer) DeleteVolumeGroupSnapshot(
+	ctx context.Context,
+	req *csi.DeleteVolumeGroupSnapshotRequest,
+) (*csi.DeleteVolumeGroupSnapshotResponse, error) {
+	// FIXME: more checking of the request in needed
+	// 1. verify that all snapshots in the request are all snapshots in the group
+	// 2. delete the group
+
+	mgr := NewManager(cs.Driver.GetInstanceID(), nil, req.GetSecrets())
+	defer mgr.Destroy(ctx)
+
+	groupSnapshot, err := mgr.GetVolumeGroupSnapshotByID(ctx, req.GetGroupSnapshotId())
+	if err != nil {
+		return nil, status.Errorf(
+			codes.Internal,
+			"failed to get volume group snapshot with id %q: %v",
+			req.GetGroupSnapshotId(), err)
+	}
+	defer groupSnapshot.Destroy(ctx)
+
+	err = groupSnapshot.Delete(ctx)
+	if err != nil {
+		return nil, status.Errorf(
+			codes.Internal,
+			"failed to delete volume group snapshot %q: %v",
+			groupSnapshot, err)
+	}
+
+	return &csi.DeleteVolumeGroupSnapshotResponse{}, nil
+}
+
+// GetVolumeGroupSnapshot is sortof optional, only used for
+// static/pre-provisioned VolumeGroupSnapshots.
+func (cs *ControllerServer) GetVolumeGroupSnapshot(
+	ctx context.Context,
+	req *csi.GetVolumeGroupSnapshotRequest,
+) (*csi.GetVolumeGroupSnapshotResponse, error) {
+	mgr := NewManager(cs.Driver.GetInstanceID(), nil, req.GetSecrets())
+	defer mgr.Destroy(ctx)
+
+	groupSnapshot, err := mgr.GetVolumeGroupSnapshotByID(ctx, req.GetGroupSnapshotId())
+	if err != nil {
+		return nil, status.Errorf(
+			codes.Internal,
+			"failed to get volume group snapshot with id %q: %v",
+			req.GetGroupSnapshotId(), err)
+	}
+	defer groupSnapshot.Destroy(ctx)
+
+	csiVGS, err := groupSnapshot.ToCSI(ctx)
+	if err != nil {
+		return nil, status.Error(codes.Aborted, err.Error())
+	}
+
+	return &csi.GetVolumeGroupSnapshotResponse{
+		GroupSnapshot: csiVGS,
+	}, nil
+}