Unable to obtain isolated JDBC connection (Java/Docker/Kubernetes/Skaffold)

[foggy crystal]

Hello guys.

I'm trying to have 3 deployments :

• Mysql database
• Backend
• Frontend

On docker desktop.

The Issue is that the backend fails to connect to the database. Here are my files:
application.properties

spring.application.name=commune-connect
spring.flyway.locations=classpath:db/migration
spring.datasource.url=jdbc:mysql://localhost:3306/communeconnect?autoReconnect=true
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=example
spring.flyway.enabled=false

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

skaffold.yml

apiVersion: skaffold/v2beta29
kind: Config
metadata:
  name: commune-connect
build:
  artifacts:
    - image: mysql
      context: .
      docker:
        dockerfile: Dockerfile-mysql
    - image: commune-connect-backend
      context: ./backend
      docker:
        dockerfile: Dockerfile
    - image: commune-connect-frontend
      context: ./frontend
      docker:
        dockerfile: Dockerfile
deploy:
  kubectl:
    manifests:
      - k8s/mysql-deployment.yaml
      - k8s/backend-deployment.yaml
      - k8s/frontend-deployment.yaml
portForward:
  - resourceType: deployment
    resourceName: backend-deployment
    port: 8080
    localPort: 8080
  - resourceType: deployment
    resourceName: frontend-deployment
    port: 80
    localPort: 4200
  - resourceType: deployment
    resourceName: mysql-deployment
    port: 3306
    localPort: 3306

And the deployment files (not including frontend as it is irrelevant here)

backend-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: backend
  template:
    metadata:
      labels:
        app: backend
    spec:
      containers:
        - name: backend
          image: commune-connect-backend:latest
          ports:
            - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: backend-service
spec:
  selector:
    app: backend
  ports:
    - protocol: TCP
      port: 8080
      targetPort: 8080
  type: ClusterIP

mysql-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql-deployment
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: "example"
            - name: MYSQL_DATABASE
              value: "communeconnect"
          ports:
            - containerPort: 3306
---
apiVersion: v1
kind: Service
metadata:
  name: mysql-service
spec:
  selector:
    app: mysql
  ports:
    - protocol: TCP
      port: 3306
      targetPort: 3306

Here are the related logs:

Mysql deployment pod: https://pastebin.com/DniPLuU2
Backend deployment pod: https://pastebin.com/YDyLpGgB

Im super confused

[undone geyser]

<@&987246841693360200> please have a look, thanks.

[foggy crystal]

Update on this issue, I changed in the application.properties the url from localhost to mysql-service as localhost was probably the pod of the backend, the error logs have changed to something different so I guess this was the fix. Still I wonder if I will have to create different application.properties files to override this value (or just override it another way) if for example I deploy that to AWS

[ornate lance]

You can override that in your deployment via environment variable

Or use a different profile for deployment