Container Service for Kubernetes:Use a StatefulSet to create a stateful application

Log on to the ACK console. In the left-side navigation pane, click Clusters.

On the Clusters page, find the cluster that you want to manage and click its name. In the left-side pane, choose Workloads > StatefulSets.

In the Advanced step, configure the following settings: access control, scaling, scheduling, labels, and annotations. In the Access Control section, create a ClusterIP Service. When you configure the Service, select Headless Service and click OK. Then, click Create in the lower part of the page.

Create a file named statefulset.yaml and copy the following YAML template to the file. The YAML template includes the following resources:

• A headless Service named nginx. The headless Service is used to provide a stable domain name.

• A StatefulSet that has a hostPath volume mounted.

• A LoadBalancer Service that is used to expose the StatefulSet. In this example, the Service helps you verify the features of the StatefulSet.

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  clusterIP: None  # Headless Service
  selector:
    app: nginx
  ports:
  - port: 80
    name: http
---
apiVersion: apps/v1
kind: StatefulSet   # The workload type.
metadata:
  name: nginx-test
  namespace: default  # Change the namespace based on your business requirements.
  labels:
    app: nginx
spec:
  serviceName: "nginx" # Specify the name of the headless Service you created.
  replicas: 2  # Specify the number of pods.
  selector:
    matchLabels:
      app: nginx
  template: # The pod configurations.
    metadata:
      labels: # The pod labels.
        app: nginx 
    spec:
      containers:
      - name: nginx  # The container name.
        image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6  # The version of the NGINX image.
        ports:
        - containerPort: 80  # The port exposed by the container.
          protocol: TCP  # Set the protocol to TCP or UDP.
        volumeMounts:
        - name: node-dir-volume  # The volume name. The value must be the same as the volume name specified in the following volumes section.
          mountPath: /tmp  # The mount path of the volume in the container.
      volumes:
      - name: node-dir-volume
        hostPath:
          path: /local_storage  # The directory on the host that you want to mount as a volume.
          type: DirectoryOrCreate     # If the specified directory does not exist, the system automatically creates the directory.
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-test-svc
  namespace: default  # Change the namespace based on your business requirements.
  labels:
    app: nginx
spec:
  selector:
    app: nginx  # The label used to match backend pods.
  ports:
    - port: 80           # The port provided by the Service in the cluster.
      targetPort: 80     # The port on which the application in the container listens (containerPort).
      protocol: TCP      # The protocol. Default value: TCP.
  type: LoadBalancer      # The Service type. Default value: ClusterIP. ClusterIP Services are accessible from within the cluster.