doc: add snapshot feature doc

README.md

@@ -27,6 +27,7 @@ Please refer to [`nfs.csi.k8s.io` driver parameters](./docs/driver-parameters.md
 ### Examples
  - [Basic usage](./deploy/example/README.md)
  - [fsGroupPolicy](./deploy/example/fsgroup)
+ - [Snapshot](./deploy/example/snapshot)
  - [Volume cloning](./deploy/example/cloning)
 
 ### Troubleshooting

deploy/example/snapshot/README.md

@@ -0,0 +1,76 @@
+# Volume Snapshot Example
+
+- supported from v4.3.0
+
+## Create source PVC and an example pod to write data 
+
+```console
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/deploy/example/storageclass-nfs.yaml
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/deploy/example/pvc-nfs-csi-dynamic.yaml
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/deploy/example/nginx-pod-nfs.yaml
+```
+
+### Check the Source PVC
+
+```console
+$ kubectl exec nginx-nfs -- ls /mnt/nfs
+outfile
+```
+
+## Create a snapshot on source PVC
+```console
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-sigs/csi-driver-nfs/master/deploy/example/snapshot/snapshotclass-nfs.yaml
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-sigs/csi-driver-nfs/master/deploy/example/snapshot/snapshot-nfs-dynamic.yaml
+```
+- Check snapshot Status
+
+```console
+$ kubectl describe volumesnapshot test-nfs-snapshot
+Name:         test-nfs-snapshot
+Namespace:    default
+Labels:       <none>
+Annotations:  <none>
+API Version:  snapshot.storage.k8s.io/v1
+Kind:         VolumeSnapshot
+Metadata:
+  Creation Timestamp:  2023-12-01T06:37:55Z
+  Finalizers:
+    snapshot.storage.kubernetes.io/volumesnapshot-as-source-protection
+    snapshot.storage.kubernetes.io/volumesnapshot-bound-protection
+  Generation:        1
+  Resource Version:  3901120
+  UID:               9a159fca-4824-4053-8d90-a92c25fb860f
+Spec:
+  Source:
+    Persistent Volume Claim Name:  pvc-nfs-dynamic
+  Volume Snapshot Class Name:      csi-nfs-snapclass
+Status:
+  Bound Volume Snapshot Content Name:  snapcontent-9a159fca-4824-4053-8d90-a92c25fb860f
+  Creation Time:                       2023-12-01T06:37:57Z
+  Ready To Use:                        true
+  Restore Size:                        656257
+Events:
+  Type    Reason            Age   From                 Message
+  ----    ------            ----  ----                 -------
+  Normal  CreatingSnapshot  22s   snapshot-controller  Waiting for a snapshot default/test-nfs-snapshot to be created by the CSI driver.
+  Normal  SnapshotCreated   20s   snapshot-controller  Snapshot default/test-nfs-snapshot was successfully created by the CSI driver.
+  Normal  SnapshotReady     20s   snapshot-controller  Snapshot default/test-nfs-snapshot is ready to use.
+```
+> In above example, `snapcontent-9a159fca-4824-4053-8d90-a92c25fb860f` is the snapshot name
+
+## Create a new PVC based on snapshot
+
+```console
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-sigs/csi-driver-nfs/master/deploy/example/snapshot/pvc-nfs-snapshot-restored.yaml
+kubectl apply -f https://raw.githubusercontent.com/kubernetes-sigs/csi-driver-nfs/master/deploy/example/snapshot/nginx-pod-restored-snapshot.yaml
+```
+
+ - Check data
+
+```console
+$ kubectl exec nginx-nfs-restored-snapshot -- ls /mnt/nfs
+outfile
+```
+
+### Links
+ - [CSI Snapshotter](https://github.com/kubernetes-csi/external-snapshotter)

deploy/example/snapshot/nginx-pod-restored-snapshot.yaml

@@ -0,0 +1,23 @@
+---
+kind: Pod
+apiVersion: v1
+metadata:
+  name: nginx-nfs-restored-snapshot
+spec:
+  nodeSelector:
+    "kubernetes.io/os": linux
+  containers:
+    - image: mcr.microsoft.com/oss/nginx/nginx:1.19.5
+      name: nginx-nfs
+      command:
+        - "/bin/bash"
+        - "-c"
+        - set -euo pipefail; while true; do echo $(date) >> /mnt/nfs/outfile; sleep 1; done
+      volumeMounts:
+        - name: persistent-storage
+          mountPath: "/mnt/nfs"
+          readOnly: false
+  volumes:
+    - name: persistent-storage
+      persistentVolumeClaim:
+        claimName: pvc-nfs-snapshot-restored

deploy/example/snapshot/pvc-nfs-snapshot-restored.yaml

@@ -0,0 +1,17 @@
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: pvc-nfs-snapshot-restored
+  namespace: default
+spec:
+  accessModes:
+    - ReadWriteMany
+  resources:
+    requests:
+      storage: 10Gi
+  storageClassName: nfs-csi
+  dataSource:
+    name: test-nfs-snapshot
+    kind: VolumeSnapshot
+    apiGroup: snapshot.storage.k8s.io

hack/verify-yamllint.sh

@@ -29,7 +29,7 @@ if [[ "${deployDirNum}" != "${helmDirNum}" ]]; then
   exit 1
 fi
 
-for path in "deploy/*.yaml" "deploy/example/*.yaml" "deploy/example/nfs-provisioner/*.yaml" "deploy/example/cloning/*.yaml"
+for path in "deploy/*.yaml" "deploy/example/*.yaml" "deploy/example/nfs-provisioner/*.yaml" "deploy/example/cloning/*.yaml" "deploy/example/snapshot/*.yaml"
 do
     echo "checking yamllint under path: $path ..."
     yamllint -f parsable $path | grep -v "line too long" > $LOG

test/external-e2e/run.sh

@@ -32,11 +32,11 @@ setup_e2e_binaries() {
 
     # test on alternative driver name
     sed -i "s/nfs.csi.k8s.io/$DRIVER.csi.k8s.io/g" deploy/example/storageclass-nfs.yaml
-    sed -i "s/nfs.csi.k8s.io/$DRIVER.csi.k8s.io/g" deploy/example/snapshotclass-nfs.yaml
+    sed -i "s/nfs.csi.k8s.io/$DRIVER.csi.k8s.io/g" deploy/example/snapshot/snapshotclass-nfs.yaml
     # install csi driver
     mkdir -p /tmp/csi
     cp deploy/example/storageclass-nfs.yaml /tmp/csi/storageclass.yaml
-    cp deploy/example/snapshotclass-nfs.yaml /tmp/csi/snapshotclass.yaml
+    cp deploy/example/snapshot/snapshotclass-nfs.yaml /tmp/csi/snapshotclass.yaml
     make e2e-bootstrap
     make install-nfs-server
 }