Using an Existing OBS Bucket Through a Static PV

• You have created a cluster and installed the CCE Container Storage (Everest) add-on in the cluster.
• To create a cluster using commands, ensure kubectl is used. For details, see Accessing a Cluster Using kubectl.

• If OBS volumes are used, the owner group and permission of the mount point cannot be modified.
• Every time an OBS volume is mounted to a workload through a PVC, a resident process is created in the backend. When a workload uses too many OBS volumes or reads and writes a large number of object storage files, resident processes will consume a significant amount of memory. To ensure stable running of the workload, make sure that the number of OBS volumes used does not exceed the requested memory. For example, if the workload requests for 4 GiB of memory, the number of OBS volumes should be no more than 4.
• Secure containers do not support OBS volumes.
• Hard links are not supported when common buckets are mounted.
• Read-only is not supported when an OBS PVC is mounted to a workload.

• Multiple PVs can use the same OBS storage volume with the following restrictions:
  • Do not mount multiple PVCs or PVs that use the same underlying OBS volume to a single pod. Doing so will cause pod startup failures, as not all PVCs can be mounted due to identical volumeHandle value.
  • The persistentVolumeReclaimPolicy parameter in the PVs must be set to Retain. Otherwise, when a PV is deleted, the associated underlying volume may be deleted. In this case, other PVs associated with the underlying volume malfunction.
  • If underlying storage is repeatedly used, you are required to maintain data consistency. Enable application-layer isolation and protection for ReadWriteMany to prevent multiple clients from writing to the same file, thereby avoiding data overwriting and loss.

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. Statically create a PVC and PV.
   1. Choose Storage in the navigation pane. In the right pane, click the PVCs tab. Click Create PVC in the upper right corner. On the slide-out panel, configure PVC parameters.

      Parameter	Description
      PVC Type	In this example, select OBS.
      PVC Name	Enter the PVC name, which must be unique in a namespace.
      Creation Method	If the underlying storage is available, create a PV or use an existing PV to statically create a PVC. If no underlying storage is available, select Dynamically provision. For details, see Using an OBS Bucket Through a Dynamic PV. In this example, select Create new to create both a PV and PVC on the console.
      PVa	Select an existing PV in the cluster. For details about how to create a PV, see "Creating a storage volume" in Related Operations. You do not need to specify this parameter in this example.
      OBSb	Click Select OBS. On the displayed page, select the OBS volume that meets your requirements and click OK.
      PV Nameb	Enter the PV name, which must be unique in the same cluster.
      Access Modeb	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.
      Reclaim Policyb	You can select Delete or Retain to specify the reclaim policy of the underlying storage when the PVC is deleted. For details, see PV Reclaim Policy. NOTE: If multiple PVs use the same OBS volume, use Retain to prevent the underlying volume from being deleted with a PV.
      Access Key (AK/SK)b	Custom access keys: Different IAM users use their own access keys (AK/SK). You can use IAM to control the permissions of IAM users to access OBS. (This method is recommended.) 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. Access Key (AK/SK) Permanent: Upload a key file in .csv format. For details, see Obtaining Access Keys. Global access secret (paas.longaksk): All clusters use the AK/SK of the account. This method is simple, but fine-grained access permission control cannot be implemented. If you have created a global access secret while using OBS volumes in a cluster, the system will create a secret called paas.longaksk in the kube-system namespace of the cluster. This secret is used to store the global AK/SK. The global access secret (paas.longaksk) is used by project. Once a global access secret is used, it is automatically created for each cluster within the same project. You can disable the global access secret in Settings > Cluster Settings. If the cluster does not use the global access secret, this option is not displayed. CAUTION: If the AK/SK is deleted or disabled accidentally, the container cannot use the OBS volume.
      Mount Optionsb	Enter the mounting parameter key-value pairs. For details, see Configuring OBS Mount Options.

      Note

      a: The parameter is available when Creation Method is set to Use existing.

      b: The parameter is available when Creation Method is set to Create new.

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

      You can choose Storage in the navigation pane and view the created PVC and PV on the PVCs and PVs tabs, respectively.

3. Create an application.
   1. Choose Workloads in the navigation pane. In the right pane, click the Deployments tab.
   2. Click Create Workload in the upper right corner. On the displayed page, click Data Storage in the Container Information area under Container Settings and choose Add Volume > PVC.

      Mount and use storage volumes. For details about the parameters, see Table 1. For other parameters, see Workloads.

      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 specifies a container path to which a data volume will be mounted. Do not mount the volume to a system directory such as / or /var/run. This may lead to 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. Otherwise, the files will be replaced, leading to container startup failures or workload creation failures. NOTICE: If a volume is mounted to a high-risk directory, use an account with minimum permissions to start the container. Otherwise, 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. tmp, for example, indicates that data in the mount path of the container is stored in the tmp folder of the storage volume. If this parameter is left blank, the root path will be used by default.
      Permission	Read-only: You can only read the data in the mounted volumes. Read-write: You can modify the data volumes 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 disk is mounted to the /data path of the container. The container data generated in this path is stored in the OBS volume.

   3. After the configuration, 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.

1. Use kubectl to access the cluster.
2. Create a PV.
   1. Create the pv-obs.yaml file.

      apiVersion: v1
      kind: PersistentVolume
      metadata:
        annotations:
          pv.kubernetes.io/provisioned-by: everest-csi-provisioner
          everest.io/reclaim-policy: retain-volume-only      # (Optional) The underlying volume is retained when the PV is deleted.
        name: pv-obs       # PV name
      spec:
        accessModes:
        - ReadWriteMany    # Access mode. The value must be  ReadWriteMany  for OBS.
        capacity:
           storage: 1Gi      # Storage capacity. This parameter is only for verification. It must not be empty or 0, but the specified size will not take effect.
        csi:
          driver: obs.csi.everest.io        # Dependent storage driver for the mounting
           fsType: obsfs                      # Instance type
           volumeHandle: <your_volume_id>     # Name of the OBS volume
          volumeAttributes:
            storage.kubernetes.io/csiProvisionerIdentity: everest-csi-provisioner
            everest.io/obs-volume-type: STANDARD
            everest.io/region: <your_region>                        # Region where the OBS volume is
            everest.io/enterprise-project-id: <your_enterprise_project_id>     # (Optional) Enterprise project ID. If an enterprise project is specified, you must specify the same enterprise project when creating a PVC. Otherwise, the PVC cannot bind to a PV.
          nodePublishSecretRef:            # Custom secret of the OBS volume
            name: <your_secret_name>       # Custom secret name
            namespace: <your_namespace>    # Namespace of the custom secret
        persistentVolumeReclaimPolicy: Retain    # Reclaim policy
         storageClassName: csi-obs                # StorageClass name
        mountOptions: []                         # Mount options
      
      

      Table 2 Key parameters

      Parameter	Mandatory	Description
      everest.io/reclaim-policy: retain-volume-only	No	Optional. Only retain-volume-only is supported. This parameter is valid only when the Everest version is 1.2.9 or later and the reclaim policy is Delete. If the reclaim policy is Delete and the current value is retain-volume-only, the associated PV is deleted while the underlying storage volume is retained, when a PVC is deleted.
      fsType	Yes	Instance type. The value can be obsfs or s3fs. obsfs: a parallel file system s3fs: object bucket
      volumeHandle	Yes	OBS volume name.
      everest.io/obs-volume-type	Yes	OBS StorageClass. If fsType is set to s3fs, standard buckets (STANDARD) and infrequent access buckets (WARM) are supported. This parameter is invalid when fsType is set to obsfs.
      everest.io/region	Yes	Region where the OBS bucket is deployed. For details about its value, see Regions and Endpoints.
      everest.io/enterprise-project-id	No	This parameter specifies the ID of the enterprise project where an OBS volume is created. It is applicable only to enterprise accounts with enterprise projects enabled. If an enterprise project is specified, you must specify the same enterprise project when creating a PVC. Otherwise, the PVC cannot bind to a PV. How to obtain: On the OBS console, choose Buckets or Parallel File Systems in the navigation pane. Click the name of the OBS bucket to access its details page. In the Basic Information area, locate the enterprise project and click it to access the enterprise project console. Copy the corresponding ID to obtain the ID of the enterprise project to which the object storage belongs.
      nodePublishSecretRef	No	Access key (AK/SK) used for mounting the object storage volume. You can use the AK/SK to create a secret and mount it to the PV. For details, see Using a Custom Access Key (AK/SK) to Mount an OBS Volume. Example: nodePublishSecretRef: name: secret-demo namespace: default
      mountOptions	No	Mount options. For details, see Configuring OBS Mount Options.
      persistentVolumeReclaimPolicy	Yes	A reclaim policy is supported when the cluster version is or later than 1.19.10 and the Everest version is or later than 1.2.9. The Delete and Retain reclaim policies are supported. For details, see PV Reclaim Policy. If multiple PVs use the same OBS volume, use Retain to prevent the underlying volume from being deleted with a PV. Delete: If everest.io/reclaim-policy is not specified, both the PV and storage resources will be deleted when a PVC is deleted. If everest.io/reclaim-policy is set to retain-volume-only, when a PVC is deleted, the PV will be deleted but the storage resources will be retained. Retain: When a PVC is deleted, both the PV and underlying storage resources will be retained. You need to manually delete these resources. After the PVC is deleted, the PV is in the Released state and cannot be bound to a PVC again. If you want to continue using the underlying storage resources, delete the PV first. Then, create a new PV and PVC and associate them with the underlying storage resources.
      storage	Yes	Storage capacity, in Gi. For OBS, this parameter is only for verification. It must not be empty or 0, and its value is fixed at 1. Any value you set will not take effect.
      storageClassName	Yes	StorageClass name, which is csi-obs for an OBS volume.

   2. Run the following command to create a PV:

      kubectl apply -f pv-obs.yaml
      
      

3. Create a PVC.
   1. Create the pvc-obs.yaml file.

      apiVersion: v1
      kind: PersistentVolumeClaim
      metadata:
        name: pvc-obs
        namespace: default
        annotations:
          volume.beta.kubernetes.io/storage-provisioner: everest-csi-provisioner
          everest.io/obs-volume-type: STANDARD
          csi.storage.k8s.io/fstype: obsfs
          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
          everest.io/enterprise-project-id: <your_enterprise_project_id>     # (Optional) Enterprise project ID. If an enterprise project is specified during PV creation, you must specify the same enterprise project when creating a PVC. Otherwise, the PVC cannot be bound to the PV.
      spec:
        accessModes:
        - ReadWriteMany                  # The value must be  ReadWriteMany  for OBS.
        resources:
          requests:
             storage: 1Gi 
         storageClassName: csi-obs        # StorageClass name, which must be the same as that of the PV
         volumeName: pv-obs     # PV name
      
      

      Table 3 Key parameters

      Parameter	Mandatory	Description
      csi.storage.k8s.io/node-publish-secret-name	No	Name of the custom secret specified in the PV.
      csi.storage.k8s.io/node-publish-secret-namespace	No	Namespace of the custom secret specified in the PV.
      everest.io/enterprise-project-id	No	This parameter specifies the ID of the enterprise project where an OBS volume is created. It is applicable only to enterprise accounts with enterprise projects enabled. How to obtain: On the OBS console, choose Buckets or Parallel File Systems in the navigation pane. Click the name of the OBS bucket to access its details page. In the Basic Information area, locate the enterprise project and click it to access the enterprise project console. Copy the corresponding ID to obtain the ID of the enterprise project to which the object storage belongs.
      storage	Yes	Requested capacity in the PVC, in Gi. For OBS, this parameter is only for verification. It must not be empty or 0, and its value is fixed at 1. Any value you set will not take effect.
      storageClassName	Yes	StorageClass name, which must be the same as the StorageClass of the PV in 1. StorageClass name, which is csi-obs for an OBS volume.
      volumeName	Yes	PV name, which must be the same as the PV name in 1.

   2. Run the following command to create a PVC:

      kubectl apply -f pvc-obs.yaml
      
      

4. Create an application.
   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    # Volume name, which is user-defined
                persistentVolumeClaim:
                   claimName: pvc-obs     # Name of the created PVC
      
      

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

      kubectl apply -f web-demo.yaml
      
      

      After the workload is created, you can try 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 -n <namespace> | 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 check the files in the /data path of the pods:

      kubectl exec -n <namespace> web-demo-846b489584-mjhm9 -- ls /data
      kubectl exec -n <namespace> 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 -n <namespace> web-demo-846b489584-mjhm9 --  touch /data/static
   
   

3. Run the following command to check the files in the /data path:

   kubectl exec -n <namespace> 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 -n <namespace> 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 -n <namespace> | 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 files in the /data path of the new pod have been modified:

      kubectl exec -n <namespace> web-demo-846b489584-d4d4j -- ls /data
      
      

      Expected output:

       static 
      
      

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

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

      kubectl get pod -n <namespace> | 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 command below 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 -n <namespace> web-demo-846b489584-d4d4j --  touch /data/share
      
      

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

      kubectl exec -n <namespace> 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 -n <namespace> 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.

You can also perform the operations listed in Table 4.