Docker Version 18.04.0-ce ignores unsupported options: network_mode

Question

For a small project, I want an application in a docker container to connect to the localhost of the machine. An answer to this question: From inside of a Docker container, how do I connect to the localhost of the machine? tells me the preferred way is to use --net="host" in the docker run command.

I use a compose file to start the container. And this question told me the net option was renamed to network_mode: "host".

Here is the beginning of the compose file

version: '3.6'
services:
  shiny:
    image: paulrougieux/eutradeflows
    deploy:
      restart_policy:
        condition: on-failure
    network_mode: "host"
    ports:
      - "3838:3838"

When I start this file

 sudo docker stack deploy -c stackshiny.yml shiny

I get the error:

Ignoring unsupported options: network_mode

For information

$ sudo docker version
Client:
 Version:   18.04.0-ce
Server:
 Engine:
  Version:  18.04.0-ce

How do I enable connection to a database on the host from a docker container?

Answer 1

As stated in the docs for docker-compose file network_mode:

Notes This option is ignored when deploying a stack in swarm mode with a (version 3) Compose file. network_mode: "host" cannot be mixed with links.

The network_mode cannot be used when deploying on docker swarm using docker stack deploy. This is not new with version 18.04 but is rather older.

The network_mode can only be used with docker-compose when deploying the container on the local machine using docker-compose up.