为什么我的externalName类型服务配置在Kubernetes中不起作用?

• 命名空间:应用层
  • rest应用程序
  • 数据库服务外部名称
• • 数据库服务

当我尝试从 rest-app ,我得到错误:

MySql.Data.MySql客户端.MySqlException(0x80004005):无法连接到任何指定的MySQL主机。 ---&燃气轮机;System.AggregateException异常:发生一个或多个错误。(名称或服务未知)

db-service 作为服务名称,并具有正确的user/pass。

数据库服务

apiVersion: v1
kind: Service
metadata:
  name: db-service
  namespace: data-layer
spec:
  selector:
    app: db-service
  ports:
   - port: 3306
  clusterIP: None

数据库服务外部名称

apiVersion: v1
kind: Service
metadata:
  name: db-service
  namespace: app-layer
spec:
  type: ExternalName
  externalName: db-service.data-layer.service.cluster.local
  ports:
    - port: 3306

rest应用程序

apiVersion: apps/v1
kind: Deployment
metadata:
  name: rest-app
  namespace: app-layer
  labels:
    app: rest-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: rest-app
  template:
    metadata:
      labels:
        app: rest-app
    spec:
      containers:
        - name: rest-app
          image: restapp:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 5000
          env:
            # These are from a secret I defined, and the logs show
            # the rest app gets them correctly
            - name: MYSQL_ROOT_USERNAME
              valueFrom:
                secretKeyRef:
                  name: db-credentials
                  key: db-username
            - name: MYSQL_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: db-credentials
                  key: db-password
            # I hard-coded this to the externalName I created. 
            # Is that right?
            - name: MYSQL_URL
              value: db-service

• 在应用层名称空间中创建externalName正确吗?
• 我需要用不同的定义吗?
• docker容器中的C#应用程序是否可以不引用 哪个是externalName服务的名称?