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

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

On the Clusters page, find the cluster you want 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 Cluster IP 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 as needed.
  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 name of the container.
        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 as needed.
  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.