MySQL

对于单实例有状态应用，会使用PersistentVolume和Deployment。

创建mysql-deployment.yaml

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
  - port: 3306
  selector:
    app: mysql
  clusterIP: None
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - 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

创建部署

kubectl create -f mysql-deployment.yaml

查看部署情况

kubectl describe deployment mysql

列出pods

kubectl get pods -l app=mysql

查看PersistentVolumeClaim

kubectl describe pvc mysql-pv-claim

访问MySQL实例

运行MySQL客户端连接server

kubectl run -it --rm --image=mysql:5.6 --restart=Never mysql-client -- mysql -h mysql -ppassword

此时即进入mysql交互界面

mysql> show databases;

更新deployment

Deployment使用的image或其他配置也可以需改，并通过kubectl apply 生效。

但对于有状态的应用，需要注意：

• 不要scale应用，而本实例中PersistentVolume也仅与一个Pod关联

• 策略选择为Recreate，从而避免rolling update

删除deployment

kubectl delete deployment,svc mysql
kubectl delete pvc mysql-pv-claim