Compose: How to connect container to both custom bridge and host network // Basler cameras in docker containers

Docker Desktop
,
1

Hi, i’m not sure if the topic category is right, so correct me if wrong.

I would like to know if it is possible to connect a service to both a custom defined bridge network aswell as to the docker’s predefined host network. In my application i would like to take advantage of docker’s dns resolution between services hence the custom bridge. At the same time however i am developing this application for Basler cameras. It looks like that Basler cameras can be detected inside docker only when using the host network basler docker .

Is it possible to connect a service to both custom-defined bridge network and docker host network?
In the Documentation i could find the following way to have a service to be connected to the host:

services:
  web:
    networks:
      hostnet: {}

networks:
  hostnet:
    external: true
    name: host

but when i try to use:

version: '3.8'

services:
  opc_base:
    build: ./OPCUA

  opcua_server:
    build: ./OPCUA/Server
    depends_on:
      - opc_base
    ports:
      - "4080:4080"
    networks:
      - opcua_network

  orchestrator:
    build: ./OPCUA/Engine
    depends_on:
      opcua_server:
    networks:
      - opcua_network
      - camera_to_host:{}

networks:
  opcua_network:
    driver: bridge
  camera_to_host:
    external: true
    name: host

i get the following error:

Error response from daemon: network-scoped alias is supported only for containers in user defined networks

If instead i use the network_mode:host option in compose as follows:

version: '3.8'

services:
  opc_base:
    build: ./OPCUA

  opcua_server:
    build: ./OPCUA/Server
    depends_on:
      - opc_base
    ports:
      - "4080:4080"
    networks:
      - opcua_network

  orchestrator:
    build: ./OPCUA/Engine
    depends_on:
      opcua_server:
    networks:
      - opcua_network
    network_mode: host

networks:
  opcua_network:
    driver: bridge

I get the following error message:

Error response from daemon: failed to add interface vetha640e1a to sandbox: error setting interface “vetha640e1a” IP to xxx.xx.0.4/16: cannot program address xxx.xx.0.4/16 in sandbox interface because it conflicts with existing route {Ifindex: 139 Dst: xxx.xx.0.0/16 Src: xxx.xx.0.1 Gw: Flags: Table: 254 Realm: 0}

Other users proposed a workaround as in workaround but this is cumbersome, as the application runs multiple containers.

To Wrap Up:

  • How can i connect a container to the host and a custom defined network using compose?

if not possible // does not solve the problem:

  • Has anyone experience with Basler cameras inside docker containers? How to use the camera in a bridge network (and not host) ?

My main goal would be to be able to run everything on a bridge, allowing acces to Basler cameras (they use the GenIcam standard). It looks like the GenIcam uses some sort of discovery method that is not allowed inside a container.

2

There is no such thing as “connecting to the host network”. The host network mode is the lack of network isolation, so it means exactly that you don’t have a Docker network. Your app in the container is not isolated and can see the original network of the host.

You created your topic in the Docker Desktop category, which is another problem, as the host mode gives you the network of the virtual machine, not the physical host.

3

Thank you for your reply. I was confused but now it is more clear.