Creating a StatefulSet Mounted with an SFS Turbo Volume

Scenario

CCE allows you to use an existing SFS Turbo volume to create a StatefulSet.

Prerequisites

You have created a CCE cluster and installed the CSI plug-in (everest) in the cluster.

Notes and Constraints

The following configuration example applies to clusters of Kubernetes 1.15 or later.

Procedure

1. Create an SFS Turbo volume and record the volume name.
2. Use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
3. Create a YAML file for creating the workload. Assume that the file name is sfsturbo-statefulset-example.yaml.

   touch sfsturbo-statefulset-example.yaml

   vi sfsturbo-statefulset-example.yaml

   Configuration example:

   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: sfsturbo-statefulset-example
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: sfsturbo-statefulset-example
     template:
       metadata:
         labels:
           app: sfsturbo-statefulset-example
       spec:
         volumes: 
         - name: pvc-sfsturbo-example 
           persistentVolumeClaim:
             claimName: pvc-sfsturbo-example     
         containers:
         - name: container-0
           image: 'nginx:latest'
           volumeMounts:
             - name: pvc-sfsturbo-example
               mountPath: /tmp
         restartPolicy: Always
         imagePullSecrets:
         - name: default-secret 
     serviceName: sfsturbo-statefulset-example-headless
     updateStrategy:
       type: RollingUpdate

   Table 1 Key parameters

   Parameter	Description
   replicas	Number of pods.
   name	Name of the new workload.
   image	Image used by the workload.
   mountPath	Mount path of a container.
   serviceName	Service corresponding to the workload. For details about how to create a Service, see Creating a StatefulSet.
   claimName	Name of an existing PVC.

   

   spec.template.spec.containers.volumeMounts.name and spec.template.spec.volumes.name must be consistent because they have a mapping relationship.

4. Create the StatefulSet.

   kubectl create -f sfsturbo-statefulset-example.yaml

Verifying Persistent Storage of an SFS Turbo Volume

1. Query the pod and SFS Turbo volume of the deployed workload (for example, sfsturbo-statefulset-example).
   1. Run the following command to query the pod name of the workload:

      kubectl get po | grep sfsturbo-statefulset-example

      Expected outputs:

      sfsturbo-statefulset-example-0   1/1     Running   0          2m5s

   2. Run the following command to check whether an SFS Turbo volume is mounted to the /tmp directory:

      kubectl exec sfsturbo-statefulset-example-0 -- mount|grep /tmp

      Expected outputs:

      192.168.0.108:/ on /tmp type nfs (rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nolock,noresvport,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.0.108,mountvers=3,mountport=20048,mountproto=tcp,local_lock=all,addr=192.168.0.108)

2. Run the following command to create a file named test in the /tmp directory:

   kubectl exec sfsturbo-statefulset-example-0 -- touch /tmp/test

3. Run the following command to view the file in the /tmp directory:

   kubectl exec sfsturbo-statefulset-example-0 -- ls -l /tmp

   Expected outputs:

   -rw-r--r-- 1 root root     0 Jun  1 02:50 test

4. Run the following command to delete the pod named sfsturbo-statefulset-example-0:

   kubectl delete po sfsturbo-statefulset-example-0

5. Check whether the file still exists after the pod is rebuilt.
   1. Run the following command to query the name of the rebuilt pod:

      kubectl get po

      Expected outputs:

      sfsturbo-statefulset-example-0   1/1     Running   0          2m

   2. Run the following command to view the file in the /tmp directory:

      kubectl exec sfsturbo-statefulset-example-0 -- ls -l /tmp

      Expected outputs:

      -rw-r--r-- 1 root root     0 Jun  1 02:50 test

      The test file still exists after the pod is rebuilt, indicating that the data in the SFS Turbo volume can be persistently stored.