rbd: add types.Snapshot interface

The rbdSnapshot/rbdImage object implements all functions for a useful
Snapshot interface. The rbd.Manager will be able to use this for
providing VolumeGroupSnapshot support.

Signed-off-by: Niels de Vos <ndevos@ibm.com>

internal/rbd/types/snapshot.go

@@ -0,0 +1,38 @@
+/*
+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 types
+
+import (
+	"context"
+	"time"
+
+	"github.com/container-storage-interface/spec/lib/go/csi"
+)
+
+type Snapshot interface {
+	journalledObject
+
+	// Destroy frees the resources used by the Snapshot.
+	Destroy(ctx context.Context)
+
+	// Delete removes the snapshot from the storage backend.
+	Delete(ctx context.Context) error
+
+	ToCSI(ctx context.Context) (*csi.Snapshot, error)
+
+	GetCreationTime(ctx context.Context) (*time.Time, error)
+}