[系统运维]k8s运行mysql服务

k8s部署mysql服务

mysql-pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  hostPath: #得挂载一个空目录
    path: "/Users/joy/mysqlSVC"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi

mysql-deploy.yaml

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
  - port: 3306 #如果这里的port和pod的containerPort不一致，则需要通过targetPort显式指定，否则无法建立映射
  selector:
    app: mysql
---
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
        imagePullPolicy: IfNotPresent
        name: mysql
        env:
          # Use secret in real usage
        - name: MYSQL_ROOT_PASSWORD
          value: t1234
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim

应用yaml

$ kubectl apply -f mysql-pv.yaml
$ kubectl apply -f mysql-deploy.yaml

查看确认是否生效：

$ kubectl get pod,svc,deploy,pv,pvc,rs,ingress 
NAME                        READY   STATUS    RESTARTS   AGE
pod/mysql-54dd7bb48-dxstj   1/1     Running   0          20m
pod/test                    1/1     Running   0          16m

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP    97d
service/mysql        ClusterIP   10.96.111.53   <none>        3306/TCP   20m

NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/mysql   1/1     1            1           20m

NAME                               CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
persistentvolume/mysql-pv-volume   20Gi       RWO            Retain           Bound    default/mysql-pv-claim   manual                  20m

NAME                                   STATUS   VOLUME            CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/mysql-pv-claim   Bound    mysql-pv-volume   20Gi       RWO            manual         20m

NAME                              DESIRED   CURRENT   READY   AGE
replicaset.apps/mysql-54dd7bb48   1         1         1       20m

验证：

$ kubectl exec -it pod/mysql-54dd7bb48-dxstj  -- mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.6.51 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

• 在pod内可以通过环境变量看到相应的service，其环境变量的key和service name保持一致。
• 如果此时service删除了或者变动了service name，pod内不会及时感应到，不是热生效的。需要重启pod才能生效。

通过pod查看service: test.yaml

apiVersion: v1
kind: Pod
metadata:
  name: test
spec:
  containers:
  - name: test
    image: library/busybox
    imagePullPolicy: IfNotPresent
    command: [ "/bin/sh", "-ce", "tail -f /dev/null" ]

$ kubectl apply -f test.yaml 
pod/test created

$ kubectl exec -it pod/test -- /bin/sh
/ # env
......
MYSQL_PORT_3306_TCP_ADDR=10.96.111.53
MYSQL_PORT_3306_TCP_PORT=3306
MYSQL_PORT_3306_TCP_PROTO=tcp
MYSQL_SERVICE_HOST=10.96.111.53
MYSQL_SERVICE_PORT=3306
MYSQL_PORT=tcp://10.96.111.53:3306
MYSQL_PORT_3306_TCP=tcp://10.96.111.53:3306
......
/ # 

mysql常用指令

• 查看数据库：

mysql> show databases;

• 查看表

mysql> use db; // 选中数据库
mysql> show tables; // 查看有哪些数据表
mysql> describe 表名; // 查看表结构