Allow internal connections between compose and applications by default

[robgraeber]

What problem will this feature address?

I setup postgres via compose and I'm trying to connect it to an application via internal url. However the application can't find it and I'm not sure if I need to add dokploy-network or something else to the compose file.

Compose file:

services:
  db:
    image: postgres:17
    container_name: postgres17
    restart: unless-stopped
    environment:
      POSTGRES_USER: ${POSTGRES_USER}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
      POSTGRES_DB: ${POSTGRES_DB}
    ports:
      - '5432:5432'
    volumes:
      - pgdata:/var/lib/postgresql/data
    healthcheck:
      test:
        - CMD-SHELL
        - pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 30s
    networks:
      - mediacreatorprogrpcstaging-db-01e1ey
    labels:
      - traefik.http.routers.mediacreatorprogrpcstaging-db-01e1ey-23-web.rule=Host(`mediacreatorprogrpcstaging-db-01e1ey-b6b5cb-51-81-35-203.traefik.me`)
      - traefik.http.routers.mediacreatorprogrpcstaging-db-01e1ey-23-web.entrypoints=web
      - traefik.http.services.mediacreatorprogrpcstaging-db-01e1ey-23-web.loadbalancer.server.port=3000
      - traefik.http.routers.mediacreatorprogrpcstaging-db-01e1ey-23-web.service=mediacreatorprogrpcstaging-db-01e1ey-23-web
      - traefik.enable=true
volumes:
  pgdata: null
networks:
  mediacreatorprogrpcstaging-db-01e1ey:
    name: mediacreatorprogrpcstaging-db-01e1ey
    external: true

Describe the solution you'd like

I'm expecting it to work out of the box

Describe alternatives you've considered

I ended up setting the postgres db up as an application which can communicate with other applications. Ultimately I am doing all this as a workaround for custom domain support for databases.

Is adding dokploy-network to the compose file what's missing?

Additional context

No response

Will you send a PR to implement it?

No

[djsisson]

@robgraeber your application needs to be in the same network as the above compose in order to see the dB

So if your app is in dokploy-network then either

1. change compose to use dokploy-network
2. add your app to the above network listed in the compose as external

[robgraeber]

@djsisson yeah I figured that's the case. If dokploy-network is the default network for applications, is there downside to adding new compose services to that network by default?

[djsisson]

ideally you want each service to see as little as possible, so an app with a db needs to be in its own network together, and then the app can also sit in a proxy network. That way, nothing but your app has access to your db, ( this assumes you don't add docker api access to other containers ofc)

but its up to you, you can stick everything in one network, just be wary of service name conflicts

i.e you have 2 compose based stacks both with the service 'postgres' means you can't now use that name as a way to communicate as docker would round robin the requests to both containers.