Docker-compose access LAN from containers

Question

Suppose I have 2 services in my docker-compose:

version: "2.4"

services:
  postgres:
    build: 
      context: .
      dockerfile: ./docker_config/dockerfiles/postgres.Dockerfile
    volumes:
      - ./docker_volumes/db/postgresql:/var/lib/postgresql    

  initializer:
    build:
      context: .
      dockerfile: ./docker_config/dockerfiles/initializer.Dockerfile
    depends_on: postgres

initializer accesses postgres using "postgres" hostname in the network created for this docker-compose file, but now I want initializer to also interact with some host in LAN, which initializer can't access now (all requests just time out).

I tried using network-mode: bridge on both containers and on initializer only, and LAN access worked, but initializer could not access postgres in these cases.

How to make both LAN and postgres container accessible from initializer container?

Answer 1

The solution was to add another network to initializer service, not override the default. The code for clarity:

version: "2.4"

networks:
  lan_access:
    driver: bridge

services:
  postgres:
    build: 
      context: .
      dockerfile: ./docker_config/dockerfiles/postgres.Dockerfile
    volumes:
      - ./docker_volumes/db/postgresql:/var/lib/postgresql    

  initializer:
    build:
      context: .
      dockerfile: ./docker_config/dockerfiles/initializer.Dockerfile
    depends_on: postgres
    networks:
      - lan_access
      - default