I’m trying out a few new things right now, and I wanted to create a small Spring/mySQL application. I’ve set up a docker-compose file as the following:

version: '3.3'
services:
  docker-mysql:
    container_name: docker-mysql
    image: mysql:5.7
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=root
    volumes:
      - db_data:/var/lib/mysql
      - ./initalize.sql:/docker-entrypoint-initdb.d/initalize.sql:ro
    ports:
      - 3306:3306
    expose:
      - 3306
volumes:
  db_data: {}

In the initalize.sql I set up a base TEST database with a few test tables and fill a few of them up, it works fine, I could query elements via command line.

On the other hand I cannot connect to it via Spring, I have the following application.properties file:

spring.jpa.hibernate.ddl-auto=none
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect
spring.datasource.url=jdbc:mysql://localhost:3306/TEST?useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

Every time I try to launch the app it gets (I’m not running the app in a docker image, it’s running on Windows) a com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure error, and it can’t find the server.

I also tried to connect to change the datasource url to jdbc:mysql://docker-mysql:3306/TEST?useSSL=false but it didn’t work either.