Ansible `docker_container` options `network_mode` and `networks` - are they intersecting?

Question

I'm building a playbook where I want to deploy a container to a host network. The Ansible docs mention two options: network_mode and networks. If I want to connect my container to the default host network, is the option (syntax as in Ansible playbooks):

network_mode: host

equivalent to:

networks:
  name: host

?

If not, what would be the network to which the container connects in both cases (if it connects at all?)

Answer 1

This is more of a Docker question than an Ansible question. You can find additional details beyond what I've put here in my answer by reading through, for example, the Network settings section of the docker run documentation.

The networks key allows you to connect your container to a named network.

The network_mode key allows you to select the type of network to create for your container (host, bridge, none, or the network environment of a specific container). It doesn't allow you to connect directly to a named network.

So if you have a network named host available that uses host networking mode, then:

network_mode: host

Is equivalent to:

networks:
  - name: host

But in general, they let you do distinct things.