使用Kubernetes部署MySQL+WordPress

前提条件

部署MySQL和WordPress

编写yaml文件

应用yaml文件

存在问题及解决方案

创建PV(持久化卷)

创建一个PVC(持久化卷声明)

部署添加PVC

查看PV对应的主机存储

删除资源

查看资源

删除deployment和service

查看主机数据

删除PVC和PV

删除主机数据

前提条件

拥有Kubernetes集群环境，可参考：Kubernetes集群搭建
理解Kubernetes部署知识，可参考：使用Kubernetes部署第一个应用、Deloyment控制器

部署MySQL和WordPress

编写yaml文件

部署mysql和wordpress，需要编写对应的deployment，同时需要暴露应用，需要编写对应的service。为了简便这里把这些deployment和service全部编写在同一个yaml中。

[root@k8s-master01 db8]# vi wordpress-mysql.yaml

内容如下

apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-mysql8
  labels:
    app: wordpress-mysql8
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress-mysql8
  template:
    metadata:
      labels:
        app: wordpress-mysql8
    spec:
      containers:
      - name: mysql8
        image: registry.cn-hangzhou.aliyuncs.com/my-common-images/mysql:8.4.3
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: "your_mysql_root_password"
        - name: MYSQL_DATABASE
          value: "wordpress"
        - name: MYSQL_USER
          value: "wordpress_user"
        - name: MYSQL_PASSWORD
          value: "your_wordpress_user_password"
        ports:
        - containerPort: 3306
---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-mysql8-service
  labels:
    app: wordpress-mysql8
spec:
  type: ClusterIP
  ports:
  - port: 3306
    targetPort: 3306
  selector:
    app: wordpress-mysql8
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress
  template:
    metadata:
      labels:
        app: wordpress
    spec:
      containers:
      - name: wordpress
        image: registry.cn-hangzhou.aliyuncs.com/my-common-images/wordpress:latest
        env:
        - name: WORDPRESS_DB_HOST
          value: wordpress-mysql8-service
        - name: WORDPRESS_DB_USER
          value: "wordpress_user"
        - name: WORDPRESS_DB_PASSWORD
          value: "your_wordpress_user_password"
        - name: WORDPRESS_DB_NAME
          value: "wordpress"
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-service
  labels:
    app: wordpress
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
  selector:
    app: wordpress

注意：记得将 your_mysql_root_password 和 your_wordpress_user_password 替换为安全的自定义密码，并且根据集群的网络和安全策略进行必要的调整，如配置防火墙以允许外部访问 NodePort。

应用yaml文件

[root@k8s-master01 db8]# kubectl apply -f wordpress-mysql.yaml
deployment.apps/wordpress-mysql8 created
service/wordpress-mysql8-service created
deployment.apps/wordpress created
service/wordpress-service created

查看部署，查看服务

[root@k8s-master01 db8]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
wordpress 1/1 1 1 12s
wordpress-mysql8 1/1 1 1 12s

[root@k8s-master01 db8]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 443/TCP 78d
wordpress-mysql8-service ClusterIP 10.15.203.40 3306/TCP 4m56s
wordpress-service NodePort 10.10.170.192 80:32201/TCP 4m56s

看到映射的NodePort 端口为32201，每个人查到的不一样，以查到的端口为准

浏览器访问节点ip:32201

选择合适语言，这里使用English为例，点击Continue

根据提示填写信息，测试环境密码建议修改简单些，便于测试。

根据提示输入登录信息，进入WordPress主页，如下

存在问题及解决方案

存在一个问题，MySQL的数据存储在Pod中，如果过程中Pod被删除重建，MySQL的数据也被删除了，可使用PV和PVC来解决这个问题。

创建PV(持久化卷)

Kubernetes 集群中创建一个持久化卷，它代表了集群中的一块存储资源，可以是本地磁盘、网络存储等。以下是一个使用本地磁盘路径创建 PV 的示例，假设你想将数据存储在主机的/root/datatest/mysql目录下（可以根据实际情况修改这个路径）：

创建PV的yaml文件

[root@k8s-master01 db8]# vi mysql-pv.yaml

内容如下

apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv
spec:
  capacity:
    storage: 10Gi  # 根据需求设置存储容量，这里设置为10GB
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /root/datatest/mysql

创建 PV

[root@k8s-master01 db8]# kubectl apply -f mysql-pv.yaml
persistentvolume/mysql-pv created

创建一个PVC(持久化卷声明)

接下来，创建一个持久化卷声明，它用于向 Kubernetes 集群请求所需的存储资源。PVC 会与合适的 PV 进行绑定，以获取实际的存储。

[root@k8s-master01 db8]# vi mysql-pvc.yaml

内容如下

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 8Gi  # 根据实际需求设置请求的存储容量，这里设置为8GB，应小于等于PV的容量

创建 PVC

[root@k8s-master01 db8]# kubectl apply -f mysql-pvc.yaml
persistentvolumeclaim/mysql-pvc created

部署添加PVC

修改wordpress-mysql.yaml的MySQL Deployment，在spec.template.spec.containers下的mysql8容器部分），添加以下内容：

 volumeMounts:
  - name: mysql-data
   mountPath: /var/lib/mysql
volumes:
- name: mysql-data
 persistentVolumeClaim:
  claimName: mysql-pvc

修改后的完整yaml文件内容如下：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-mysql8
  labels:
    app: wordpress-mysql8
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress-mysql8
  template:
    metadata:
      labels:
        app: wordpress-mysql8
    spec:
      containers:
      - name: mysql8
        image: registry.cn-hangzhou.aliyuncs.com/my-common-images/mysql:8.4.3
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: "your_mysql_root_password"
        - name: MYSQL_DATABASE
          value: "wordpress"
        - name: MYSQL_USER
          value: "wordpress_user"
        - name: MYSQL_PASSWORD
          value: "your_wordpress_user_password"
        ports:
        - containerPort: 3306
        volumeMounts:
          - name: mysql-data
            mountPath: /var/lib/mysql
      volumes:
      - name: mysql-data
        persistentVolumeClaim:
          claimName: mysql-pvc
---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-mysql8-service
  labels:
    app: wordpress-mysql8
spec:
  type: ClusterIP
  ports:
  - port: 3306
    targetPort: 3306
  selector:
    app: wordpress-mysql8
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress
  template:
    metadata:
      labels:
        app: wordpress
    spec:
      containers:
      - name: wordpress
        image: registry.cn-hangzhou.aliyuncs.com/my-common-images/wordpress:latest
        env:
        - name: WORDPRESS_DB_HOST
          value: wordpress-mysql8-service
        - name: WORDPRESS_DB_USER
          value: "wordpress_user"
        - name: WORDPRESS_DB_PASSWORD
          value: "your_wordpress_user_password"
        - name: WORDPRESS_DB_NAME
          value: "wordpress"
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: wordpress-service
  labels:
    app: wordpress
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
  selector:
    app: wordpress

完成上述修改后，再次执行apply命令来更新 MySQL 的部署，使其使用映射到主机的持久化存储。

[root@k8s-master01 db8]# kubectl apply -f wordpress-mysql.yaml
deployment.apps/wordpress-mysql8 configured
service/wordpress-mysql8-service unchanged
deployment.apps/wordpress unchanged
service/wordpress-service unchanged

重新访问浏览器

节点ip:32201

重新根据提示设置WordPress，进入WordPress主页，能正常访问。

查看PV对应的主机存储

查看pod在哪台主机运行

[root@k8s-master01 db8]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
wordpress-6b69d95596-jgbnw 1/1 Running 0 53m 10.244.85.225 k8s-node01
wordpress-mysql8-64c987b8cd-vxqtk 1/1 Running 0 6m59s 10.244.85.230 k8s-node01

看到pod在k8s-node01机器运行，到对应的k8s-node01机器查看pv对应的存储目录

# 在运行pod的机器执行
[root@k8s-node01 ~]# ls /root/datatest/mysql/
‘#ib_16384_0.dblwr’ auto.cnf ca-key.pem ib_buffer_pool mysql.ibd private_key.pem sys
‘#ib_16384_1.dblwr’ binlog.000001 ca.pem ibdata1 mysql.sock public_key.pem undo_001
‘#innodb_redo’ binlog.000002 client-cert.pem ibtmp1 mysql_upgrade_history server-cert.pem undo_002
‘#innodb_temp’ binlog.index client-key.pem mysql performance_schema server-key.pem wordpress

查看到相应的MySQL卷挂载到主机的数据。

删除资源

查看资源

[root@k8s-master01 db8]# kubectl get deploy
NAME READY UP-TO-DATE AVAILABLE AGE
wordpress 1/1 1 1 81m
wordpress-mysql8 1/1 1 1 81m

[root@k8s-master01 db8]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 443/TCP 78d
wordpress-mysql8-service ClusterIP 10.15.203.40 3306/TCP 82m
wordpress-service NodePort 10.10.170.192 80:32201/TCP 82m

[root@k8s-master01 db8]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS VOLUMEATTRIBUTESCLASS REASON AGE
mysql-pv 10Gi RWO Retain Bound default/mysql-pvc 62m
mysql-pv-volume 20Gi RWO Retain Bound default/mysql-pv-claim manual 39d

[root@k8s-master01 db8]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS VOLUMEATTRIBUTESCLASS AGE
mysql-pv-claim Bound mysql-pv-volume 20Gi RWO manual 39d
mysql-pvc Bound mysql-pv 10Gi RWO 57m

删除deployment和service

[root@k8s-master01 db8]# kubectl delete deploy wordpress wordpress-mysql8
deployment.apps “wordpress” deleted
deployment.apps “wordpress-mysql8” deleted

[root@k8s-master01 db8]# kubectl delete svc wordpress-mysql8-service wordpress-service
service “wordpress-mysql8-service” deleted
service “wordpress-service” deleted

查看主机数据

查看PV对应的主机目录，发现数据还在

[root@k8s-node01 ~]# ls /root/datatest/mysql/
‘#ib_16384_0.dblwr’ auto.cnf ca-key.pem ib_buffer_pool mysql.sock public_key.pem undo_001
‘#ib_16384_1.dblwr’ binlog.000001 ca.pem ibdata1 mysql_upgrade_history server-cert.pem undo_002
‘#innodb_redo’ binlog.000002 client-cert.pem mysql performance_schema server-key.pem wordpress
‘#innodb_temp’ binlog.index client-key.pem mysql.ibd private_key.pem sys