使用Deployment运行单实例有状态应用

第一步: 创建 service、pvc、deployment

# cat mysql-deployment.yml

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
  - port: 3306
  selector:
    app: mysql
  clusterIP: None  # 创建Headless services,DNS直接解析service的name为POD的IP, 当service只有一个pod时，这种方式最简单。

---
apiVersion: v1
kind: PersistentVolumeClaim # 创建的前提是有可用的PV。
metadata:
  name: mysql-pv-claim
spec:
  accessModes:
    - ReadWriteOnce   # 申请能在一个节点上进行读写的数据卷
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate # 因为底层数据卷不支持多pod同时读写，所以先stop第一个pod,才创建新的。
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        env:
          # Use secret in real usage
        - name: MYSQL_ROOT_PASSWORD
          value: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim

$ kubectl create -f ./mysql-deployment.yml

第二步: 测试部署成功

# 这里可以直接通过service的name访问POD
$ kubectl run -it --rm --image=mysql:5.6 --restart=Never mysql-client -- mysql -h mysql -ppassword