Using an OBS Bucket Through a Dynamic PV

• 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.

• 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.

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. 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 no underlying storage is available, select Dynamically provision to create a PVC, PV, and underlying storage on the console in cascading mode. If the underlying storage is available, create a PV or use an existing PV to statically create a PVC. For details, see Using an Existing OBS Bucket Through a Static PV. In this example, select Dynamically provision.
      Storage Classes	The default StorageClass name of OBS volumes is csi-obs. You can specify customize a StorageClass and configure its reclaim policy and binding mode. For details, see Creating a StorageClass Through the Console.
      (Optional) Storage Volume Name Prefix	Available only when the cluster version is v1.23.14-r0, v1.25.9-r0, v1.27.6-r0, v1.28.4-r0, or later, and Everest v2.4.15 or later is installed in the cluster. This parameter specifies the name of the underlying storage that is automatically created. The actual underlying storage name is in the format of "Storage volume name prefix + PVC UID". If this parameter is left blank, the default prefix pvc will be used. For example, if the storage volume name prefix is set to test, the actual underlying storage name is test-{UID}.
      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. Object bucket: provides reliable, high-performance, secure, and budget-friendly storage for data. They have no restrictions on the quantity of files or storage capacity.
      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 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.
      Enterprise Project	This parameter is available only for enterprise accounts with enterprise projects enabled. The enterprise project can be the default project, the project where the cluster is located, or the project specified by the StorageClass.
      Resource Tag	You can add resource tags to classify resources. This is supported only when the Everest version in the cluster is v2.4.204 or later. You can create predefined tags on the TMS console. These tags are available to all resources that support tags. You can use these tags to improve the tag creation and resource migration efficiency. NOTE: After a dynamic PV of the OBS type is created, the resource tags cannot be updated on the CCE console. To update OBS resource tags, go to the OBS console.

   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. 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    # OBS
          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
          everest.io/enterprise-project-id: <your_enterprise_project_id>  # (Optional) Enterprise project ID
          everest.io/csi.volume-name-prefix: test  # (Optional) Storage volume name prefix of the automatically-created underlying storage
      spec:
        accessModes:
          - ReadWriteMany             # The value must be  ReadWriteMany  for OBS.
        resources:
          requests:
             storage: 1Gi                # OBS volume capacity
         storageClassName: csi-obs     # The StorageClass is OBS.
      
      

      Table 2 Key parameters

      Parameter	Mandatory	Description
      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.
      csi.storage.k8s.io/fstype	Yes	Instance type. The value can be obsfs or s3fs. obsfs: a parallel file system s3fs: object bucket
      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.
      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. To obtain an enterprise project ID, log in to the EPS console, click the name of the target enterprise project, and copy the enterprise project ID.
      everest.io/csi.volume-name-prefix	No	(Optional) This parameter is available only when the cluster version is v1.23.14-r0, v1.25.9-r0, v1.27.6-r0, v1.28.4-r0, or later, and Everest v2.4.15 or later is installed in the cluster. This parameter specifies the name of the underlying storage that is automatically created. The actual underlying storage name is in the format of "Storage volume name prefix + PVC UID". If this parameter is left blank, the default prefix pvc will be used. Enter 1 to 26 characters that cannot start or end with a hyphen (-). Only lowercase letters, digits, and hyphens (-) are allowed. For example, if the storage volume name prefix is set to test, the actual underlying storage name is test-{UID}.
      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 is csi-obs for an OBS volume.
      everest.io/obs-volume-tags	No	(Optional) This parameter is supported when the Everest version in the cluster is v2.4.204 or later. You can add resource tags to classify resources. You can create predefined tags on the TMS console. These tags are available to all resources that support tags. You can use these tags to improve the tag creation and resource migration efficiency.

   2. Run the following command to create a PVC:

      kubectl apply -f pvc-obs-auto.yaml
      
      

3. 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-auto     # 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 3.