目前，我正在为我的学校项目做一个Kubernetes项目。之前，我在大约六个月前使用Next.js，Sping Boot 和MySQL开发了一个Web应用程序。我现在正在尝试将这个应用程序与Kubernetes集成。最初，我为每个组件创建了一个映像，并使用“docker run”成功测试了它。然而，我在将其转换为Kubernetes时遇到了困难。
我在Sping Boot Pod上收到的错误消息是：
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure.
我知道这个错误通常是由于连接到MySQL时出现的问题，例如缺少数据库或URL不正确。
下面是我用来创建MySQL和Sping Boot pod的YAML文件的一个示例。

apiVersion: v1
kind: Namespace
metadata:
  name: lost_island

# lost_island_mysql

---

apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"

---

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
  namespace: lost_island
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: lost_island_mysql
  namespace: lost_island
  labels:
    app: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
        - name: mysql
          image: mysql:latest
          env:
            - name: MYSQL_ROOT_PASSWORD
              value: 1234
            - name: MYSQL_DATABASE
              value: lost_island
            - name: MYSQL_PASSWORD
              value: 1234
          ports:
            - containerPort: 3306
          volumeMounts:
            - name: mysql-persistent-storage
              mountPath: /var/lib/mysql
      volumes:
        - name: mysql-persistent-storage
          persistentVolumeClaim:
            claimName: mysql-pv-claim

---

apiVersion: v1
kind: Service
metadata:
  name: mysql-service
  namespace: lost_island
spec:
  selector:
    app: mysql
  ports:
    - name: mysql-port
      port: 3306
      targetPort: 3306
  type: NodePort

# lost_island_backend

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: lost_island_backend
  namespace: lost_island
  labels:
    app: springboot
spec:
  replicas: 1
  selector:
    matchLabels:
      app: springboot
  template:
    metadata:
      labels:
        app: springboot
    spec:
      containers:
        - name: springboot-app
          image: skull/lost_island_backend
          env:
            - name: SPRING_DATASOURCE_URL
              value: jdbc:mysql://mysql-service.lost_island.svc.cluster.local:3306/lost_island?serverTimezone=UTC&sessionVariables=sql_mode='NO_ENGINE_SUBSTITUTION'&jdbcCompliantTruncation=false&useSSL=false
            - name: SPRING_DATASOURCE_USERNAME
              value: root
            - name: SPRING_DATASOURCE_PASSWORD
              value: 1234
          ports:
            - containerPort: 8080
            - containerPort: 9092