Docker-compose check if mysql connection is ready

Question

I am trying to make sure that my app container does not run migrations / start until the db container is started and READY TO accept connections.

So I decided to use

Answer 1

RESTART ON-FAILURE

Since v3 condition: service_healthy is no longer available. The idea is that the developer should implement mechanism for crash recovery within the app itself. However for simple use cases a simple way to resolve this issue is to use restart option.

If mysql service status causes your application to exited with code 1 you can use one of restart policy options available. eg, on-failure

version: "3"

services:

    app:
      ...
      depends_on:
        - db:
      restart: on-failure