使用Kubernetes部署MySQL+WordPress

目录

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        <none>        443/TCP        78d
wordpress-mysql8-service   ClusterIP   10.15.203.40    <none>        3306/TCP       4m56s
wordpress-service          NodePort    10.10.170.192   <none>        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   <none>           <none>
wordpress-mysql8-64c987b8cd-vxqtk   1/1     Running   0          6m59s   10.244.85.230   k8s-node01   <none>           <none>
​

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        <none>        443/TCP        78d
wordpress-mysql8-service   ClusterIP   10.15.203.40    <none>        3306/TCP       82m
wordpress-service          NodePort    10.10.170.192   <none>        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                       <unset>                          62m
mysql-pv-volume   20Gi       RWO            Retain           Bound    default/mysql-pv-claim   manual         <unset>                          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         <unset>                 39d
mysql-pvc        Bound    mysql-pv          10Gi       RWO                           <unset>                 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
​

删除PVC和PV

[root@k8s-master01 db8]# kubectl delete pvc mysql-pvc
persistentvolumeclaim "mysql-pvc" deleted
​
[root@k8s-master01 db8]# kubectl delete pv mysql-pv
persistentvolume "mysql-pv" deleted

[root@k8s-master01 db8]# kubectl get pvc
No resources found in default namespace.
[root@k8s-master01 db8]# kubectl get pv
No resources found

查看PV对应的主机目录，数据依然存在

[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

删除PV主要是从 Kubernetes 的资源管理角度进行操作，它不会自动删除主机上对应的目录。这是因为PV只是对存储资源的一种抽象和管理方式，它与主机文件系统是松耦合的。

删除主机数据

如果需要删除数据并且确认这些数据是可以删除数据，则需要手动删除卷挂载的主机数据。

[root@k8s-node01 ~]# rm -rf /root/datatest/mysql

完成！enjoy it!