$ {DB_HOST}：在Minikube集群中部署Spring MVC应用程序时，名称无法解析

如何解决$ {DB_HOST}：在Minikube集群中部署Spring MVC应用程序时，名称无法解析

与Spring Boot的application.properties配置配合得很好，但是当我将Spring MVC与XML配置配合使用时，会失败。

登录到应用程序时，通信链接失败。

MySQL部署：

apiVersion: v1
kind: Service
metadata:
  name: employeecare-db  # DNS name 
  labels:
    app: employeecare-db
    tier: database
spec:
  ports:
    - port: 3306
      targetPort: 3306
  selector:       # mysql Pod Should contain same labels
    app: employeecare-db
    tier: database
  clusterIP: None  # We Use DNS,Thus ClusterIP is not relevant
---
# Define a 'Persistent Voulume Claim'(PVC) for Mysql Storage,dynamically provisioned by cluster
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim # name of PVC essential for identifying the storage data 
  labels:
    app: employeecare-db
    tier: database
spec:
  accessModes:
    - ReadWriteOnce   #This specifies the mode of the claim that we are trying to create.
  resources:
    requests:
      storage: 1Gi    #This will tell kubernetes about the amount of space we are trying to claim.
---
# Configure 'Deployment' of mysql server
apiVersion: apps/v1
kind: Deployment
metadata:
  name: employeecare-db
  labels:
    app: employeecare-db
    tier: database
spec:
  selector: # mysql Pod Should contain same labels 
    matchLabels:
      app: employeecare-db
      tier: database
  strategy:
    type: Recreate
  template:
    metadata:
      labels: # Must match 'Service' and 'Deployment' selectors
        app: employeecare-db
        tier: database
    spec:
      containers:
      - image: mysql:5.7 # image from docker-hub
        args:
          - "--ignore-db-dir=lost+found" # Workaround for https://github.com/docker-library/mysql/issues/186
        name: employeecare-db  
        env:
        - name: MYSQL_ROOT_PASSWORD # Setting Root Password of mysql From a 'Secret'
          valueFrom:
            secretKeyRef:
              name: secret-mysql-root # Name of the 'Secret'
              key: password   # 'key' inside the Secret which contains required 'value'
        - name: MYSQL_USER # Setting USER username on mysql From a 'Secret'
          valueFrom:
            secretKeyRef:
              name: secret-mysql-user
              key: username
        - name: MYSQL_PASSWORD # Setting USER Password on mysql From a 'Secret'
          valueFrom:
            secretKeyRef:
              name: secret-mysql-user
              key: password
        - name: MYSQL_DATABASE # Setting Database Name from a 'ConfigMap'
          valueFrom:
            configMapKeyRef:
              name: configmap-mysql
              key: name
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:        # Mounting voulume obtained from Persistent Volume Claim
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql #This is the path in the container on which the mounting will take place.
      volumes:
      - name: mysql-persistent-storage # Obtaining 'vloume' from PVC
        persistentVolumeClaim:
          claimName: mysql-pv-claim

春季部署：

kind: Service
apiVersion: v1
metadata:
  name: employeecare-app
  labels:
    name: employeecare-app
spec:
  ports:
    - nodePort: 30164 
      port: 8080      
      targetPort: 8080  
      protocol: TCP
  selector:           
    app: employeecare-app
  type: LoadBalancer       

---
apiVersion: apps/v1 
kind: Deployment    
metadata:              
  name: employeecare-app
spec:                
  selector:         
    matchLabels:
      app: employeecare-app
  replicas: 3        
  template:
    metadata:
      labels:        
        app: employeecare-app
    spec:
      containers:
        - name: employeecare-app
          image: 100598/employeecare:1.0
          ports:
            - containerPort: 8080                
          env:   # Setting Enviornmental Variables
          - name: DB_HOST   # Setting Database host address from configMap
            valueFrom: 
              configMapKeyRef:
                name: configmap-mysql  # name of configMap
                key: host
          - name: DB_NAME  # Setting Database name from configMap
            valueFrom:
              configMapKeyRef:
                name: configmap-mysql 
                key: name
          - name: DB_USERNAME  # Setting Database username from Secret
            valueFrom:
              secretKeyRef:
                name: secret-mysql-user # Secret Name
                key: username
          - name: DB_PASSWORD # Setting Database password from Secret
            valueFrom:
              secretKeyRef:
                name: secret-mysql-user
                key: password   

ConfigMap和秘密：

apiVersion: v1
kind: ConfigMap
metadata:
    name: configmap-mysql
data:
    host: employeecare-db
    name: EMPLOYEECARE

apiVersion: v1
kind: Secret
metadata:
  name: secret-mysql-root
data:
 password: cm9vdA==

apiVersion: v1
kind: Secret
metadata:
    name: secret-mysql-user
data:
    username: cm9oaXQ=
    password: MTIzNA==

注意：我正在使用带有XML配置的Spring MVC。下面是我的数据库配置

<!-- Docker DB Configs -->
<beans:bean id="dataSource"
    class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <beans:property name="driverClassName"
        value="com.mysql.cj.jdbc.Driver" />
    <beans:property name="url"
        value="jdbc:mysql://${DB_HOST}/${DB_NAME}?useSSL=true" />
    <beans:property name="username" value="${DB_USERNAME}" />
    <beans:property name="password" value="${DB_PASSWORD}" />
</beans:bean> 

谢谢。