Creating a StatefulSet Mounted with an SFS Volume

Scenario

CCE allows you to use an existing SGS volume to create a StatefulSet (by using a PVC).

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 volume by referring to PersistentVolumeClaims (PVCs) 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 sfs-statefulset-example.yaml.

   touch sfs-statefulset-example.yaml

   vi sfs-statefulset-example.yaml

   Configuration example:

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

   Table 1 Key parameters

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

   Example of mounting an SFS volume to a StatefulSet (PVC template-based, dedicated volume):

   Example YAML file:

   apiVersion: apps/v1
   kind: StatefulSet
   metadata:
     name: sfs-statefulset-example
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: sfs-statefulset-example
     template:
       metadata:
         labels:
           app: sfs-statefulset-example
       spec:
         containers:
           - name: container-0
             image: 'nginx:latest'
             volumeMounts:
               - name: pvc-sfs-auto-example
                 mountPath: /tmp
         restartPolicy: Always
         imagePullSecrets:
           - name: default-secret
     volumeClaimTemplates:
       - metadata:
           name: pvc-sfs-auto-example
           namespace: default
         spec:
           accessModes:
             - ReadWriteMany
           resources:
             requests:
               storage: 10Gi
           storageClassName: csi-nas
     serviceName: sfs-statefulset-example-headless
     updateStrategy:
       type: RollingUpdate

   

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

4. Create a StatefulSet.

   kubectl create -f sfs-statefulset-example.yaml