Container Service for Kubernetes:Batch convert YAML files using the FlexVolume2CSI command line interface

Flags

Run flexvolume2csi translate help to see all available flags.

flexvolume2csi translate [-n namespace] [-c pvc] [-o outputfile] [-p prefix] [-s suffix] [-b backupfile] [-t storageclass]

Example

This example converts a FlexVolume NAS PV and PVC to CSI.

1. Create a pv.yaml file with the following content and apply it to the FlexVolume cluster.

   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: pv-nas
   spec:
     capacity:
       storage: 5Gi
     storageClassName: nas
     accessModes:
       - ReadWriteMany
     flexVolume:
       driver: "alicloud/nas"
       options:
         server: "0cd8b4a576-u****.cn-hangzhou.nas.aliyuncs.com" # Replace with your NAS mount target address.
         path: "/k8s"
         vers: "3"
         options: "nolock,tcp,noresvport"

   kubectl apply -f pv.yaml

2. Create a pvc.yaml file with the following content and apply it.

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: pvc-nas
   spec:
     accessModes:
       - ReadWriteMany
     storageClassName: nas
     resources:
       requests:
         storage: 5Gi

   kubectl apply -f pvc.yaml

3. Confirm that the PV and PVC are bound.

   kubectl get pvc | grep pvc-nas

   Expected output:

   pvc-nas   Bound    pv-nas   5Gi       RWO            nas       10s

4. Convert all PVs and PVCs in the cluster. The -s csi flag appends -csi to the generated resource names to avoid conflicts.

   flexvolume2csi translate -s csi

5. Review the generated CSI YAML.

   cat ./outputfile.yaml

   Expected output:

   ---
   apiVersion: v1
   kind: PersistentVolume
   metadata:
     labels:
       alicloud-pvname: pv-nas-csi
     name: pv-nas-csi
   spec:
     accessModes:
     - ReadWriteMany
     capacity:
       storage: 5Gi
     csi:
       driver: nasplugin.csi.alibabacloud.com
       volumeAttributes:
         path: /k8s
         server: 0cd8b4a576-u****.cn-hangzhou.nas.aliyuncs.com
       volumeHandle: pv-nas-csi
     mountOptions:
     - nolock,tcp,noresvport
     - vers=3
     persistentVolumeReclaimPolicy: Retain
     storageClassName: nas
     volumeMode: Filesystem
   
   ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: pvc-nas-csi
     namespace: default
   spec:
     accessModes:
     - ReadWriteMany
     resources:
       requests:
         storage: 5Gi
     selector:
       matchLabels:
         alicloud-pvname: pv-nas-csi
     storageClassName: nas
     volumeMode: Filesystem
     volumeName: pv-nas-csi

Conversion targets

The conversion output depends on the volume type:

• Disk volumes without a `volumeId`: converted to inline ephemeral volumes.

• All other types: converted to CSI PV and PVC resources. The output file includes the PV, PVC, and the updated workload manifest.

Flags

Run flexvolume2csi inline-translate help to see all available flags.

flexvolume2csi inline-translate [-n namespace] [-k kind] [-i item] [-f inputfile] [-o outputfile] [-b backupfile] [-t storageclass] [-c capacity]

Example 1: Convert a disk volume without a volumeId to an ephemeral volume

1. Create and deploy the following workload in the FlexVolume cluster.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
   spec:
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           volumeMounts:
           - name: test
             mountPath: /data
           ports:
           - containerPort: 80
         volumes:
         - name: test
           flexVolume:
             driver: "alicloud/disk"
             fsType: "ext4"
             options:
               volumeSize: "20"

2. Convert the workload.

   flexvolume2csi inline-translate -k deploy -n default -i nginx

3. Review the generated CSI YAML.

   cat ./outputfile.yaml

   Expected output:

   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
     namespace: default
   spec:
     progressDeadlineSeconds: 600
     replicas: 1
     revisionHistoryLimit: 10
     selector:
       matchLabels:
         app: nginx
     strategy:
       rollingUpdate:
         maxSurge: 25%
         maxUnavailable: 25%
       type: RollingUpdate
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           imagePullPolicy: IfNotPresent
           name: nginx
           ports:
           - containerPort: 80
             protocol: TCP
           resources: {}
           terminationMessagePath: /dev/termination-log
           terminationMessagePolicy: File
           volumeMounts:
           - mountPath: /data
             name: test
         dnsPolicy: ClusterFirst
         restartPolicy: Always
         schedulerName: default-scheduler
         securityContext: {}
         terminationGracePeriodSeconds: 30
         volumes:
         - ephemeral:
             volumeClaimTemplate:
               metadata:
               spec:
                 accessModes:
                 - ReadWriteOnce
                 resources:
                   requests:
                     storage: 20Gi
           name: test

4. Before deploying, adjust the generated YAML as needed. For ephemeral volumes, specify a StorageClass:

         volumes:
         - ephemeral:
             volumeClaimTemplate:
               metadata:
               spec:
                 accessModes:
                 - ReadWriteOnce
                 resources:
                   requests:
                     storage: 20Gi
                 storageClassName: ephemeral-disk

   Alternatively, pass -t during conversion to set the StorageClass for all resources:

   flexvolume2csi inline-translate -k deploy -n default -i nginx -t ephemeral-disk

Example 2: Convert other volume types to CSI PV and PVC resources

This example uses -f to convert a StatefulSet from a local file.

1. Save the StatefulSet YAML shown at the beginning of this step as disk-static-sts.yaml.

2. Convert the StatefulSet.

   flexvolume2csi inline-translate -f disk-static-sts.yaml

3. Review the generated CSI YAML.

   cat ./outputfile.txt

   Expected output:

   ---
   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: d-bp1f3b5d0b0a8e7e6f****
   spec:
     accessModes:
     - ReadWriteOnce
     claimRef:
       kind: PersistentVolumeClaim
       name: sts-nginx-test
       namespace: default
     csi:
       driver: diskplugin.csi.alibabacloud.com
       fsType: ext4
       volumeAttributes:
         volumeId: d-bp1f3b5d0b0a8e7e6f****
       volumeHandle: d-bp1f3b5d0b0a8e7e6f****
     persistentVolumeReclaimPolicy: Delete
   
   ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: sts-nginx-test
     namespace: default
   spec:
     accessModes:
     - ReadWriteOnce
     resources: {}
     volumeName: d-bp1f3b5d0b0a8e7e6f****
   
   ---
   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: nginx
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx
     serviceName: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           name: nginx
           ports:
           - containerPort: 80
           resources: {}
           volumeMounts:
           - mountPath: /data
             name: test
         volumes:
         - name: test
           persistentVolumeClaim:
             claimName: sts-nginx-test
     updateStrategy: {}
     volumeClaimTemplates:
     - metadata:
         name: disk-ssd
       spec:
         accessModes: [ "ReadWriteOnce" ]
         storageClassName: "alicloud-disk-ssd"
         resources:
           requests:
             storage: 20Gi

   The inline FlexVolume volume is converted to a CSI PVC and PV. The StatefulSet now references the PVC instead of the inline volume. The volumeClaimTemplates section is not modified.

4. Before deploying, adjust the generated YAML as needed. For CSI disk volumes, two fields are typically missing from the generated output:

   • Storage capacity: declare the required capacity on the PVC and PV. For example, set capacity.storage: 20Gi on the PV and resources.requests.storage: 20Gi on the PVC.

   • StorageClass in volumeClaimTemplates: change storageClassName to a CSI StorageClass.

   After adjustment:

   ---
   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: d-bp1f3b5d0b0a8e7e6f****
   spec:
     accessModes:
     - ReadWriteOnce
     capacity:
       storage: 20Gi
     claimRef:
       kind: PersistentVolumeClaim
       name: sts-nginx-test
       namespace: default
     csi:
       driver: diskplugin.csi.alibabacloud.com
       fsType: ext4
       volumeAttributes:
         volumeId: d-bp1f3b5d0b0a8e7e6f****
       volumeHandle: d-bp1f3b5d0b0a8e7e6f****
     persistentVolumeReclaimPolicy: Delete
   
   ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: sts-nginx-test
     namespace: default
   spec:
     accessModes:
     - ReadWriteOnce
     resources:
       requests:
         storage: 20Gi
     volumeName: d-bp1f3b5d0b0a8e7e6f****

   Alternatively, pass -t and -c during conversion to set the StorageClass and capacity for all resources:

   flexvolume2csi inline-translate -f disk-static-sts.yaml -t <csi-storageclass> -c "20Gi"