Specify container IP as extra_hosts

[rimelek (Ákos Takács)]

@jefflockhart

What’s the proper way to add a record to the WordPress container’s /etc/hosts file with the Traefik container’s IP address?

The proper way is not adding anything to the hosts file but setting a network alias:

docker network connect

https://docs.docker.com/compose/compose-file/06-networks/

services:
  traefik:
    networks:
      default:
        aliases:
          - mysite.com

It registers the domain as an alias for the container in Docker’s built-in DNS server.

The reverse proxy is usually in a different compose project. If that’s the case, you have an extrnal network and you need to set the alias on that network and not on the default.