Docker-compose with django could not translate host name “db” to address: Name or service not known

Question

I have currently a system built with docker-compose, it creates a Django application.

Up until now I\'ve used a database inside a container (postgresql) in my testin

Answer 1

Add network, link and depends_on configuration in docker compose file.

example:

  services:
      db:
          build: .
          container_name: db
          networks:
              - djangonetwork
      web:
          build: .
          depends_on:
             - db
          links:
             - db:db
          networks:
             - djangonetwork

  networks:
      djangonetwork:
          driver: bridge

Answer 2

To the others experiencing this.

The following command (which removes all unused containers, networks, images, and optionally, volumes) solve my problem:

docker system prune

See docker document for more information

Answer 3

In the "django" part of your docker-compose.yml under "depends_on" section try adding links: - db:db after it, or even replace the depends_on: db with that.

I'll bet if you typed in docker logs (container name) you'd see it's obviously having trouble working out where "db" points to.

I think they're looking to end support for links in docker-compose in new iterations at least I read that somewhere..

Answer 4

Answering my question, this was a stupid one...

My manage.py was selecting only the base.py settings file, and was not taking into account the staging.py settings file. So it was breaking in the CLI and was not breaking inside the app.