core: add flatten-rbd-pvc command

- Flatten an RBD image corrensponding to the target PVC
- Remove the corresponding temporary RBD image

Closes: rook#222

Signed-off-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>

cmd/commands/flatten_rbd_pvc.go

@@ -0,0 +1,118 @@
+/*
+Copyright 2024 The Rook Authors. All rights reserved.
+
+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 command
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/rook/kubectl-rook-ceph/pkg/exec"
+	"github.com/rook/kubectl-rook-ceph/pkg/logging"
+
+	"github.com/spf13/cobra"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type TrashLsOutput struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
+var namespace string
+var allowInUse bool
+
+// FlattenRBDPVCCmd represents the rook commands
+var FlattenRBDPVCCmd = &cobra.Command{
+	Use:   "flatten-rbd-pvc",
+	Short: "Flatten the RBD image corresponding to the target RBD PVC",
+	Long: `Flatten the RBD image corresponding to the target RBD PVC.
+The target RBD PVC must be a cloned image and must be created by ceph-csi.
+In other words, you can't flatten static PVC by this command.
+This command removes the corresponding temporary cloned image[1]
+if the target PVC was cloned from another PVC.
+
+[1]: https://github.com/ceph/ceph-csi/blob/328e4e5a0fa06521c5508b94a5b7ff250ada1681/docs/design/proposals/rbd-snap-clone.md.`,
+	Args: cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		pvcName := args[0]
+		pvc, err := clientSets.Kube.CoreV1().PersistentVolumeClaims(namespace).Get(cmd.Context(), pvcName, metav1.GetOptions{})
+		if err != nil {
+			logging.Fatal(err, "failed to get pvc %s/%s", namespace, pvcName)
+		}
+		if pvc.DeletionTimestamp != nil {
+			logging.Fatal(fmt.Errorf("pvc %s is deleting", pvcName))
+		}
+		if pvc.Status.Phase != corev1.ClaimBound {
+			logging.Fatal(fmt.Errorf("pvc %s is not bound", pvcName))
+		}
+		pvName := pvc.Spec.VolumeName
+		pv, err := clientSets.Kube.CoreV1().PersistentVolumes().Get(cmd.Context(), pvName, metav1.GetOptions{})
+		if err != nil {
+			logging.Fatal(fmt.Errorf("failed to get pv %s", pvName))
+		}
+		imageName, ok := pv.Spec.CSI.VolumeAttributes["imageName"]
+		if !ok {
+			logging.Fatal(fmt.Errorf("pv %s would not be a CSI PVC", pvName))
+		}
+		poolName, ok := pv.Spec.CSI.VolumeAttributes["pool"]
+		logging.Fatal(fmt.Errorf("pv %s would not be a CSI PVC", pvName))
+
+		// TODO: consider clone PVC from snapshot. see https://github.com/rook/kubectl-rook-ceph/pull/229#discussion_r1467429104
+		tempImageName := imageName + "-temp"
+		if !allowInUse {
+			// TODO: check whether the target PVC is mounted
+			logging.Fatal(fmt.Errorf("can't flatten in-use pvc %s", pvcName))
+		}
+		logging.Info("removing the temporary RBD image %s/%s if exist", poolName, tempImageName)
+		// TODO: cosider radosnamespace. see https://github.com/rook/kubectl-rook-ceph/pull/229#discussion_r1467429104
+		_, err = exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "rbd", []string{"-p", poolName, "trash", "mv", tempImageName}, cephClusterNamespace, operatorNamespace, false)
+		if err != nil {
+			logging.Fatal(fmt.Errorf("failed to move rbd image %s/%s to trash", poolName, tempImageName))
+		}
+		// TODO: avoid heavy operation (trash ls). see https://github.com/rook/kubectl-rook-ceph/pull/229#discussion_r1467433441
+		out, err := exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "rbd", []string{"-p", poolName, "trash", "ls", "--format=json"}, cephClusterNamespace, operatorNamespace, true)
+		if err != nil {
+			logging.Fatal(fmt.Errorf(""))
+		}
+		var data []TrashLsOutput
+		json.Unmarshal([]byte(out), &data)
+		var id string
+		for _, d := range data {
+			if d.Name == tempImageName {
+				id = d.ID
+				break
+			}
+		}
+		if id != "" {
+			_, err = exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "ceph", []string{"rbd", "task", "add", "trash", "remove", fmt.Sprintf("%s/%s", poolName, id)}, cephClusterNamespace, operatorNamespace, false)
+			if err != nil {
+				logging.Fatal(fmt.Errorf("failed to create a task to remove %s/%s from trash", poolName, id))
+			}
+		}
+		logging.Info("flattening the target RBD image %s/%s", poolName, imageName)
+		_, err = exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "rbd", []string{"-p", poolName, "flatten", imageName}, cephClusterNamespace, operatorNamespace, false)
+		if err != nil {
+			logging.Fatal(fmt.Errorf("failed to flatten %s/%s", poolName, imageName))
+		}
+	},
+}
+
+func init() {
+	FlattenRBDPVCCmd.Flags().StringVarP(&namespace, "namespace", "n", "default", "pvc's namespace")
+	FlattenRBDPVCCmd.Flags().BoolVarP(&allowInUse, "allow-in-use", "a", false, "allow to flatten in-use image")
+}

cmd/main.go

@@ -42,5 +42,6 @@ func addcommands() {
 		command.DestroyClusterCmd,
 		command.SubvolumeCmd,
 		command.RadosCmd,
+		command.FlattenRBDPVCCmd,
 	)
 }

docs/flatten-rbd-pvc.md

@@ -0,0 +1,10 @@
+# Flatten RBD PVC
+
+`flatten-rbd-pvc` command is to flatten the RBD image corresponding to the target RBD PVC.
+Fore more details about flatten, see [the Ceph offical document](https://docs.ceph.com/en/latest/rbd/rbd-snapshot/#flattening-a-cloned-image).
+
+By flattening RBD images, we can bypass the problems specific to non-flattened cloned image like https://github.com/ceph/ceph-csi/discussions/4360.
+
+## Examples.
+
+TBD