Kubernetes环境下WordPress与MySQL连接失败求助

问题概述 #

已通过YAML部署WordPress和MySQL Pod，Pod创建状态正常，通过kubectl port-forward wordpress 8080:80可在浏览器访问WordPress页面，但页面始终提示**"Error establishing a database connection"**。已验证WordPress Pod可ping通MySQL，但数据库连接失败。

部署命令：kubectl apply -f "filename.yaml"

部署配置文件 #

wordpress.yaml

apiVersion: v1
kind: Pod
metadata:
  name: wordpress
spec:
  containers:
  - name: app
    image: wordpress:latest
    env:
    - name: "WORDPRESS_DB_HOST"
      value: "mysql-service"  
    - name: "WORDPRESS_DB_NAME"
      value: "MysqlDB"
    - name: "WORDPRESS_DB_USER"
      value: "admin"
    - name: "WORDPRESS_DB_PASSWORD"
      value: "Test"
    ports:
    - containerPort: 80

database.yaml

apiVersion: v1
kind: Pod
metadata:
  name: database
  labels: 
    name: mysql-pod
spec:
  containers:
  - name: database
    image: mysql:latest
    env:
      - name: "MYSQL_USER"
        value: "admin"
      - name: "MYSQL_PASSWORD"
        value: "Test"
      - name: "MYSQL_DATABASE"
        value: "MysqlDB"
      - name: "MYSQL_ROOT_PASSWORD"
        value: "TFBern_3013"  
    ports:
    - containerPort: 3306
--- # Mysql Service definiert
apiVersion: v1
kind: Service
metadata:
  name: mysql-service
spec:
  ports:
    - port: 3306
  selector:
    name: mysql-pod

排查步骤与修复方案 #

1. 修复MySQL用户连接权限 #

默认情况下，MYSQL_USER创建的用户仅允许从localhost连接，而WordPress是通过集群内部IP访问MySQL，需授权用户从任意IP连接：

• 进入MySQL Pod：

  kubectl exec -it database -- mysql -uroot -pTFBern_3013
  

• 执行授权SQL：

  GRANT ALL PRIVILEGES ON MysqlDB.* TO 'admin'@'%' IDENTIFIED BY 'Test';
  FLUSH PRIVILEGES;
  

2. 验证端口连通性 #

ping通仅说明网络可达，需确认3306端口可访问：

• 在WordPress Pod内执行端口测试：

  kubectl exec -it wordpress -- telnet mysql-service 3306
  

若连接失败，检查MySQL容器是否正常监听3306端口（查看MySQL日志），或Service selector是否匹配（当前配置中Pod标签name: mysql-pod与Service selector一致，此部分无问题）。

3. 查看容器日志定位细节 #

• 查看WordPress日志：

  kubectl logs wordpress
  

• 查看MySQL日志：

  kubectl logs database
  

日志会给出连接失败的具体原因，如权限拒绝、数据库未创建等。

4. 优化建议：使用Deployment替代独立Pod #

当前使用的独立Pod无自愈能力，建议改为Deployment，确保Pod故障时自动重建：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress
  template:
    metadata:
      labels:
        app: wordpress
    spec:
      containers:
      - name: app
        image: wordpress:latest
        env:
        - name: WORDPRESS_DB_HOST
          value: mysql-service
        - name: WORDPRESS_DB_NAME
          value: MysqlDB
        - name: WORDPRESS_DB_USER
          value: admin
        - name: WORDPRESS_DB_PASSWORD
          value: Test
        ports:
        - containerPort: 80

内容的提问来源于stack exchange，提问作者squdidle 1337