运行一个单实例有状态应用

通过创建一个 Kubernetes Deployment 并使用 PersistentVolumeClaim 将其连接到已有的 PersistentVolume 来运行一个有状态的应用

1. 创建一个MySQL数据存储卷的PersistentVolume，mysql-pv.yaml

   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: mysql-pv-volume
     labels:
       type: local
   spec:
     storageClassName: manual
     capacity:
       storage: 20Gi
     accessModes:
       - ReadWriteOnce
     hostPath:
       path: "/mnt/data"
   ---
   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: mysql-pv-claim
   spec:
     storageClassName: manual
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 20Gi

2. 执行PersistentVolume创建

   kubectl apply -f mysql-pv.yaml

3. 查看新建的PersistentVolumeClaim

   kubectl describe pvc mysql-pv-claim

4. 创建一个MySQL Deployment，mysql-deployment.yaml

   apiVersion: v1
   kind: Service
   metadata:
     name: mysql
   spec:
     ports:
     - port: 3306
     selector:
       app: mysql
     clusterIP: None
   ---
   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:
             # 在实际中使用 secret
           - 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

5. 检查创建的应用是否成功

   kubectl describe deployment mysql-deployment #显示Deployment信息
   kubectl get pods -l app=mysql-deployment #查看Pod列表
   kubectl decribe pod <pod-name> #查看Pod信息