Using an OBS Bucket Through a Dynamic PV

Constraints

• If OBS volumes are used, the owner group and permission of the mount point cannot be modified.
• Hard links are not supported when common buckets are mounted.
• OBS allows a single user to create a maximum of 100 buckets. If a large number of dynamic PVCs are created, the number of buckets may exceed the upper limit, and no more OBS buckets can be created. In this case, use OBS by calling its API or SDK and do not mount OBS buckets to workloads.

Automatically Creating an OBS Volume on the Console

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. Dynamically create a PVC and PV.
   1. In the navigation pane on the left, choose Storage. Then click the PVCs tab. In the upper right corner, click Create PVC. In the displayed dialog box, configure the parameters.

      Parameter	Description
      PVC Type	In this example, select OBS.
      OBS Endpoint	To access OBS in a CCE Autopilot cluster, you need to create an OBS endpoint.
      PVC Name	Enter the PVC name, which must be unique in the same namespace.
      Creation Method	If no underlying storage is available, select Dynamically provision to create a PVC, PV, and underlying storage on the console in cascading mode. If underlying storage is available, select either Use existing or Create new. For details about static creation, see Using an Existing OBS Bucket Through a Static PV. In this example, select Dynamically provision.
      Storage Classes	The storage class of OBS volumes is csi-obs.
      Instance Type	Parallel file system: a high-performance file system provided by OBS. It provides millisecond-level access latency, TB/s-level bandwidth, and million-level IOPS. Parallel file systems are recommended. Object bucket: a container that stores objects in OBS. All objects in a bucket are at the same logical level.
      OBS Class	You can select the following object bucket types: Standard: Applicable when a large number of hotspot files or small-sized files need to be accessed frequently (multiple times per month on average) and require fast access response. Infrequent access: Applicable when data is not frequently accessed (fewer than 12 times per year on average) but requires fast access response.
      Access Mode	OBS volumes support only ReadWriteMany, indicating that a storage volume can be mounted to multiple nodes in read/write mode. For details, see Volume Access Modes.
      Access Key (AK/SK)	Custom: Customize a secret if you want to assign different user permissions to different OBS storage devices. For details, see Using a Custom Access Key (AK/SK) to Mount an OBS Volume. Only secrets with the secret.kubernetes.io/used-by = csi label can be selected. The secret type is cfe/secure-opaque. If no secret is available, click Create Secret to create one. Name: Enter a secret name. Namespace: Select the namespace where the secret is located. Access Key (AK/SK): Upload a key file in .csv format. For details, see Obtaining an Access Key.

   2. Click Create to create a PVC and a PV.

      In the navigation pane on the left, choose Storage. View the created PVC and PV on the PVCs and PVs tabs, respectively.

3. Create a workload.
   1. In the navigation pane on the left, choose Workloads. Then click the Deployments tab.
   2. In the upper right corner, click Create Workload. On the displayed page, click Data Storage in the Container Settings area and click Add Volume to select PVC.
      Mount and use storage volumes. For details about the parameters, see Table 1. For other parameters, see Creating a Workload.

      Table 1 Mounting a storage volume

      Parameter	Description
      PVC	Select an existing OBS volume.
      Mount Path	Enter a mount path, for example, /tmp. This parameter indicates the container path that the volume will be mounted to. Do not mount the volume to a system directory such as / or /var/run. This may cause container errors. Mount the volume to an empty directory. If the directory is not empty, ensure that there are no files that affect container startup, or the files will be replaced, which will lead to a container startup or workload creation failure. NOTICE: If a volume is mounted to a high-risk directory, use an account with minimum permissions to start the container, or high-risk files on the host may be damaged.
      Subpath	Enter the subpath of the storage volume and mount a path in the storage volume to the container. In this way, different folders of the same storage volume can be used in a single pod. Enter a subpath, for example, tmp, indicating that data in the mount path of the container is stored in the tmp directory of the storage volume. If this parameter is left blank, the root path is used by default.
      Permission	Read-only: You can only read the data in the mounted volume. Read-write: You can modify the volume mounted to the path. Newly written data will not be migrated if the container is migrated, which may cause data loss.

      In this example, the volume is mounted to the /data path of the container. The container data generated in this path is stored in the OBS volume.

      

   3. Configure other parameters and click Create Workload.

      After the workload is created, the data in the container mount directory will be persistently stored. Verify the storage by referring to Verifying Data Persistence and Sharing.

(kubectl) Automatically Creating an OBS Volume

1. Use kubectl to connect to the cluster.
2. Use StorageClass to dynamically create a PVC and PV.
   1. Create the pvc-obs-auto.yaml file.

      apiVersion: v1
      kind: PersistentVolumeClaim
      metadata:
        name: pvc-obs-auto
        namespace: default
        annotations:
          everest.io/obs-volume-type: STANDARD    # Object storage type.
          csi.storage.k8s.io/fstype: obsfs        # Instance type.
          csi.storage.k8s.io/node-publish-secret-name: <your_secret_name>       # Custom secret name.
          csi.storage.k8s.io/node-publish-secret-namespace: <your_namespace>    # Namespace of the custom secret.
      spec:
        accessModes:
          - ReadWriteMany             # The value must be ReadWriteMany for object storage.
        resources:
          requests:
            storage: 1Gi               # OBS volume capacity.
        storageClassName: csi-obs    # The StorageClass type of OBS

      Table 2 Key parameters

      Parameter	Mandatory	Description
      everest.io/obs-volume-type	Yes	OBS storage class. If fsType is set to s3fs, STANDARD (standard bucket) and WARM (infrequent access bucket) are supported. This parameter is invalid when fsType is set to obsfs.
      csi.storage.k8s.io/fstype	Yes	Instance type. The value can be obsfs or s3fs. obsfs: Parallel file system, which is mounted using obsfs. s3fs: Object bucket, which is mounted using s3fs.
      csi.storage.k8s.io/node-publish-secret-name	No	Custom secret name. (Recommended) Select this option if you want to assign different user permissions to different OBS storage devices. For details, see Using a Custom Access Key (AK/SK) to Mount an OBS Volume.
      csi.storage.k8s.io/node-publish-secret-namespace	No	Namespace of a custom secret.
      storage	Yes	Requested capacity in the PVC, in Gi. For OBS, this field is used only for verification (cannot be empty or 0). Its value is fixed at 1, and any value you set does not take effect for OBS.
      storageClassName	Yes	Storage class name. The storage class name of OBS volumes is csi-obs.

   2. Run the following command to create a PVC:

      kubectl apply -f pvc-obs-auto.yaml

3. Create a workload.
   1. Create a file named web-demo.yaml. In this example, the OBS volume is mounted to the /data path.

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: web-demo
        namespace: default
      spec:
        replicas: 2
        selector:
          matchLabels:
            app: web-demo
        template:
          metadata:
            labels:
              app: web-demo
          spec:
            containers:
            - name: container-1
              image: nginx:latest
              volumeMounts:
              - name: pvc-obs-volume    #Volume name, which must be the same as the volume name in the volumes field.
                mountPath: /data  # Location where the storage volume is mounted.
            imagePullSecrets:
              - name: default-secret
            volumes:
              - name: pvc-obs-volume    # Custom volume name
                persistentVolumeClaim:
                  claimName: pvc-obs-auto    # Name of the created PVC.

   2. Run the following command to create a workload that the OBS volume is mounted to:

      kubectl apply -f web-demo.yaml

      After the workload is created, you can try Verifying Data Persistence and Sharing.

Verifying Data Persistence and Sharing

1. View the deployed application and files.
   1. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      Expected output:

      web-demo-846b489584-mjhm9   1/1     Running   0             46s
      web-demo-846b489584-wvv5s   1/1     Running   0             46s

   2. Run the following commands in sequence to view the files in the /data path of the pods:

      kubectl exec web-demo-846b489584-mjhm9 -- ls /data
      kubectl exec web-demo-846b489584-wvv5s -- ls /data

      If no result is returned for both pods, no file exists in the /data path.

2. Run the following command to create a file named static in the /data path:

   kubectl exec web-demo-846b489584-mjhm9 --  touch /data/static

3. Run the following command to view the created file in the /data path:

   kubectl exec web-demo-846b489584-mjhm9 -- ls /data

   Expected output:

   static

4. Verify data persistence.
   1. Run the following command to delete the pod named web-demo-846b489584-mjhm9:

      kubectl delete pod web-demo-846b489584-mjhm9

      Expected output:

      pod "web-demo-846b489584-mjhm9" deleted

      After the deletion, the Deployment controller automatically creates a replica.

   2. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      The expected output is as follows, in which web-demo-846b489584-d4d4j is the newly created pod:

      web-demo-846b489584-d4d4j   1/1     Running   0             110s
      web-demo-846b489584-wvv5s    1/1     Running   0             7m50s

   3. Run the following command to check whether the file in the /data path of the new pod has been modified:

      kubectl exec web-demo-846b489584-d4d4j -- ls /data

      Expected output:

      static

      The static file is retained, indicating that the data in the file system can be stored persistently.

5. Verify data sharing.
   1. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      Expected output:

      web-demo-846b489584-d4d4j   1/1     Running   0             7m
      web-demo-846b489584-wvv5s   1/1     Running   0             13m

   2. Run the following command to create a file named share in the /data path of either pod: In this example, select the pod named web-demo-846b489584-d4d4j.

      kubectl exec web-demo-846b489584-d4d4j --  touch /data/share

      Check the files in the /data path of the pod.

      kubectl exec web-demo-846b489584-d4d4j -- ls /data

      Expected output:

      share
      static

   3. Check whether the share file exists in the /data path of another pod (web-demo-846b489584-wvv5s) as well to verify data sharing.

      kubectl exec web-demo-846b489584-wvv5s -- ls /data

      Expected output:

      share
      static

      After you create a file in the /data path of a pod, if the file is also created in the /data path of the other pod, the two pods share the same volume.

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