K8s之MySQL实现数据持久化

[root@master ~]# yum -y install nfs-utils
[root@master ~]# systemctl enable rpcbind
[root@master lv]# mkdir -p /nfsdata/mysql
[root@master ~]# vim /etc/exports
/nfsdata *(rw,sync,no_root_squash)
[root@master ~]# systemctl start nfs-server
[root@master ~]# systemctl enable nfs-server
[root@master ~]# showmount -e
Export list for master:
/nfsdata *

[root@master lv]# vim mysql-pv.yaml      #编写pv的yaml文件
kind: PersistentVolume
apiVersion: v1
metadata:
  name: mysql-pv
spec:
  accessModes:
    - ReadWriteOnce        #访问模式定义为只能以读写的方式挂载到单个节点
  capacity:
    storage: 1Gi
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  nfs:
    path: /nfsdata/mysql
    server: 192.168.20.6
[root@master lv]# kubectl apply -f mysql-pv.yaml  #执行yaml文件

[root@master lv]# vim mysql-pvc.yaml       #编写pvc的yaml文件
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: mysql-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: nfs      #这里指定关联的PV名称
[root@master lv]# kubectl apply -f mysql-pvc.yaml       #执行yaml文件

[root@master lv]# kubectl get pv     
NAME       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM               STORAGECLASS   REASON   AGE
mysql-pv   1Gi        RWO            Retain           Bound    default/mysql-pvc   nfs                     5m8s
[root@master lv]# kubectl get pvc
NAME        STATUS   VOLUME     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mysql-pvc   Bound    mysql-pv   1Gi        RWO            nfs            60s

[root@master lv]# vim mysql-pod.yaml     #编写pod的yaml文件
 
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - name: mysql
        image: mysql:5.7
        env:                        #以下是设置MySQL数据库的密码
        - name: MYSQL_ROOT_PASSWORD
          value: 123.com
        ports:
        - containerPort: 3306
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql          #MySQL容器的数据都是存在这个目录的，要对这个目录做数据持久化
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pvc       #指定pvc的名称
 
---          #以下是创建svc的yaml文件
apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  type: NodePort
  ports:
  - port: 3306
    targetPort: 3306
    nodePort: 31111
  selector:
    app: mysql
  selector:
    app: mysql
[root@master lv]# kubectl apply -f mysql-pod.yaml     #执行yaml文件
[root@master lv]# kubectl get pod        #确定pod运行正常
NAME                     READY   STATUS    RESTARTS   AGE
mysql-6d898f8bcb-lhqxb   1/1     Running   0          51s

[root@master lv]# kubectl exec -it mysql-6d898f8bcb-lhqxb -- mysql -uroot -p123.com
mysql> create database test;
mysql> use test;
mysql> create table my_id(id int(4));
mysql> insert my_id values(9527);
mysql> select * from my_id;            #确认有数据存在

[root@master lv]# kubectl get pod -o wide          #查看pod运行在哪个节点
NAME                     READY   STATUS    RESTARTS   AGE   IP           NODE     NOMINATED NODE   
mysql-6d898f8bcb-cz8gr   1/1     Running   0          10m   10.244.1.3   node01   
#我这是运行在node01节点，现在去node01节点手动将其容器删除
[root@node01 ~]# docker ps       #查看MySQL容器的ID
[root@node01 ~]# docker rm -f 1a524e001732    #将MySQL的容器删除
#由于Deployment的保护策略，当删除容器后，它会根据pod的yaml文件生成一个新的容器，但新容器的ID号就变了
#回到master节点，登录到数据库，查看数据是否还存在
[root@master lv]# kubectl exec -it mysql-6d898f8bcb-cz8gr -- mysql -uroot -p123.com
mysql> select * from test.my_id;           #数据还在，OK
+------+
| id   |
+------+
| 1996 |
+------+
1 row in set (0.01 sec)

[root@master lv]# kubectl get pod -o wide   #查看容器所在节点，我这里还是在node01
#然后我这里将node01关机，然后动态查看pod的状态
[root@master lv]# kubectl get pod -o wide -w    #动态查看pod的状态
#大概node01关机五分钟左右，可以看到pod就被转移到node02上运行了。
NAME                     READY   STATUS    RESTARTS   AGE   IP           NODE     NOMINATED NODE   READINESS GATES
mysql-6d898f8bcb-cz8gr   1/1     Running   0          20m   10.244.1.3   node01   <none>           <none>
 
mysql-6d898f8bcb-cz8gr   1/1     Running   0          20m   10.244.1.3   node01   <none>           <none>
mysql-6d898f8bcb-cz8gr   1/1     Terminating   0          25m   10.244.1.3   node01   <none>           <none>
mysql-6d898f8bcb-gp4t5   0/1     Pending       0          0s    <none>       <none>   <none>           <none>
mysql-6d898f8bcb-gp4t5   0/1     Pending       0          0s    <none>       node02   <none>           <none>
mysql-6d898f8bcb-gp4t5   0/1     ContainerCreating   0          0s    <none>       node02   <none>           <none>
mysql-6d898f8bcb-gp4t5   1/1     Running             0          1s    10.244.2.4   node02   <none>           <none>

[root@master lv]# mysql -uroot -p123.com -h 192.168.33.244 -P 31111
MySQL [(none)]> select * from test.my_id;    #查看数据
+------+
| id   |
+------+
| 1996 |
+------+
1 row in set (0.01 sec