Docker, Springboot and Mysql : com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

Question

I try to run a Springboot app with mysql connection on Docker. Without docker, it works well. But when I try to deploy on a container, I have com.mysql.cj.exceptions.CJCom

Answer 1

As your Spring Boot application is also launched in a docker image, you can't used the port exposed by docker, but instead you need to use the original port of the image.

In application.properties you need to use:

spring.datasource.url = jdbc:mysql://mysql:3306/db