core: add flatten-rbd-pvc command

Add flatten-rbd-pvc command to accomplish the following things:

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

Closes: #222

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

.github/workflows/go-test.yaml

@@ -83,6 +83,14 @@ jobs:
           set -ex
           kubectl rook-ceph rbd ls replicapool
 
+      - name: Flatten a PVC clone
+        run: |
+          set -ex
+          tests/github-action-helper.sh install_external_snapshotter
+          tests/github-action-helper.sh wait_for_rbd_pvc_clone_to_be_bound
+
+          kubectl rook-ceph flatten-rbd-pvc rbd-pvc-clone
+
       - name: Subvolume command
         run: |
           set -ex
@@ -251,6 +259,14 @@ jobs:
           set -ex
           kubectl rook-ceph --operator-namespace test-operator -n test-cluster rbd ls replicapool
 
+      - name: Flatten a PVC clone
+        run: |
+          set -ex
+          tests/github-action-helper.sh install_external_snapshotter
+          tests/github-action-helper.sh wait_for_rbd_pvc_clone_to_be_bound
+
+          kubectl rook-ceph --operator-namespace test-operator -n test-cluster flatten-rbd-pvc rbd-pvc-clone
+
       - name: Subvolume command
         run: |
           set -ex

cmd/commands/flatten_rbd_pvc.go

@@ -0,0 +1,156 @@
+/*
+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 (
+	"context"
+	"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"
+)
+
+const (
+	storageProvisionerBetaAnnotation    = "volume.beta.kubernetes.io/storage-provisioner"
+	storageProvisionerAnnotation        = "volume.kubernetes.io/storage-provisioner"
+	cephCSIRBDStorageProviderAnnotation = "volume.beta.kubernetes.io/storage-provisioner"
+)
+
+type RBDInfoOutput struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
+type Watcher struct {
+	Address string `json:"address"`
+}
+
+type RBDStatusOutput struct {
+	Watchers []Watcher `json:"watchers"`
+}
+
+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.
+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/devel/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))
+		}
+		if pvc.Annotations[storageProvisionerAnnotation] != cephCSIRBDStorageProviderAnnotation && pvc.Annotations[storageProvisionerBetaAnnotation] != cephCSIRBDStorageProviderAnnotation {
+			logging.Fatal(fmt.Errorf("PVC %s is not a CSI RBD PVC", pvcName))
+		}
+
+		shouldDeleteTempImage := false
+		if pvc.Spec.DataSource != nil {
+			switch pvc.Spec.DataSource.Kind {
+			case "PersistentVolumeClaim":
+				shouldDeleteTempImage = true
+			case "VolumeSnapshot":
+			default:
+				logging.Fatal(fmt.Errorf("PVC %s is not a cloned image", 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 doesn't contains `imageName` in VolumeAttributes", pvName))
+		}
+		poolName, ok := pv.Spec.CSI.VolumeAttributes["pool"]
+		if !ok {
+			logging.Fatal(fmt.Errorf("PV %s doesn't contains `pool` in VolumeAttributes", pvName))
+		}
+
+		if !allowInUse {
+			out, err := exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "rbd", []string{"-p", poolName, "status", imageName, "--format=json"}, operatorNamespace, cephClusterNamespace, false)
+			if err != nil {
+				logging.Fatal(fmt.Errorf("failed to stat %s/%s", poolName, imageName))
+			}
+			var status RBDStatusOutput
+			json.Unmarshal([]byte(out), &status)
+			if len(status.Watchers) > 0 {
+				logging.Fatal(fmt.Errorf("flatten in-use pvc %s is not allowed. If you want to do, run with `--allow-in-use` option", pvcName))
+			}
+		}
+
+		if shouldDeleteTempImage {
+			deleteTempImage(cmd.Context(), poolName, imageName)
+		}
+		logging.Info("flattening the target RBD image %s/%s", poolName, imageName)
+		_, err = exec.RunCommandInOperatorPod(cmd.Context(), clientSets, "ceph", []string{"rbd", "task", "add", "flatten", fmt.Sprintf("%s/%s", poolName, imageName)}, operatorNamespace, cephClusterNamespace, false)
+		if err != nil {
+			logging.Fatal(fmt.Errorf("failed to flatten %s/%s", poolName, imageName))
+		}
+	},
+}
+
+func deleteTempImage(ctx context.Context, poolName, imageName string) {
+	tempImageName := imageName + "-temp"
+
+	out, err := exec.RunCommandInOperatorPod(ctx, clientSets, "rbd", []string{"-p", poolName, "info", "--format=json", tempImageName}, operatorNamespace, cephClusterNamespace, false)
+	if err != nil {
+		logging.Error(fmt.Errorf("failed to run `rbd info` for rbd image %s/%s", poolName, tempImageName))
+		return
+	}
+	var info RBDInfoOutput
+	json.Unmarshal([]byte(out), &info)
+	id := info.ID
+	logging.Info("removing the temporary RBD image %s/%s if exist", poolName, tempImageName)
+	_, err = exec.RunCommandInOperatorPod(ctx, clientSets, "rbd", []string{"-p", poolName, "trash", "mv", tempImageName}, operatorNamespace, cephClusterNamespace, false)
+	if err != nil {
+		logging.Fatal(fmt.Errorf("failed to move rbd image %s/%s to trash", poolName, tempImageName))
+	}
+	if id != "" {
+		_, err = exec.RunCommandInOperatorPod(ctx, clientSets, "ceph", []string{"rbd", "task", "add", "trash", "remove", fmt.Sprintf("%s/%s", poolName, id)}, operatorNamespace, cephClusterNamespace, false)
+		if err != nil {
+			logging.Fatal(fmt.Errorf("failed to create a task to remove %s/%s from trash", poolName, id))
+		}
+	}
+}
+
+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 +1,12 @@
+# 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 official 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.
+
+```bash
+kubectl rook-ceph flatten-rbd-pvc rbd-pvc-clone
+```

tests/github-action-helper.sh

@@ -267,6 +267,28 @@ install_minikube_with_none_driver() {
   sudo -E minikube start --kubernetes-version="$1" --driver=none --memory 6g --cpus=2 --addons ingress --cni=calico
 }
 
+install_external_snapshotter() {
+  EXTERNAL_SNAPSHOTTER_VERSION=7.0.2
+  curl -L "https://github.com/kubernetes-csi/external-snapshotter/archive/refs/tags/v${EXTERNAL_SNAPSHOTTER_VERSION}.zip" -o external-snapshotter.zip
+  unzip -d /tmp external-snapshotter.zip
+  cd "/tmp/external-snapshotter-${EXTERNAL_SNAPSHOTTER_VERSION}"
+
+  kubectl kustomize client/config/crd | kubectl create -f -
+  kubectl -n kube-system kustomize deploy/kubernetes/snapshot-controller | kubectl create -f -
+}
+
+wait_for_rbd_pvc_clone_to_be_bound() {
+  kubectl create -f https://raw.githubusercontent.com/rook/rook/master/deploy/examples/csi/rbd/pvc-clone.yaml
+
+  timeout 100 bash <<-'EOF'
+    until [ $(kubectl get pvc rbd-pvc-clone -o jsonpath='{.status.phase}') == "Bound" ]; do
+      echo "waiting for the pvc clone to be in bound state"
+      sleep 1
+    done
+EOF
+  timeout_command_exit_code
+}
+
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