[DISCUSSION] How to replace easily Docker by Podman for Ansible Docker users? about ansible-podman-collections HOT 5 OPEN

@manics thanks, that's a really important question. A lot of tasks rely on docker module outputs and of course it shouldn't break.
I think there could be a few approaches:

1. Podman project tries to be compliant with docker outputs and if we see inconsistency or difference, we can always report it. Of course not everything could and should be fixed.
2. We can catch podman output and if there are well known issues, just hack it to be compatible with docker output format. The same we should do with input arguments if there are different names for example.

Regarding option to explicitly set an engine, I think it would be totally reasonable to have it, like use_engine: docker use_engine: podman.
The main goal of course will be to make them their outputs and functionality as close as possible.

from ansible-podman-collections.

Would any of these options include unifying the output of the modules- or is the assumption that podman would change to match the docker output? For example to lookup an exposed port at the moment:

• docker_container: registered_fact.ansible_facts.docker_container.NetworkSettings.Ports['8888/tcp'].0.HostPort
• containers.podman.podman_container: registered_fact.container.NetworkSettings.Ports.0.hostPort

If it's not feasible to have them behave identically could the Ansible service module be an example to follow- if you're doing something simple use the generic module/wrapper, but if you depend on particular outputs or features use e.g. the systemd module instead?

from ansible-podman-collections.

Amazingly, option 2 works as is:

- name: Run docker hidden in podman
  containers.podman.podman_container:
    name: test-container
    image: alpine
    state: present
    executable: docker
    env:
      MYSQL_ROOT_PASSWORD: "2211"

"podman_actions": [
        "docker run --name test-container --env MYSQL_ROOT_PASSWORD=2211 --detach=True alpine"
    ]

$ docker ps -a
CONTAINER ID        IMAGE                  COMMAND             CREATED             STATUS                      PORTS                    NAMES
13a5bc49ead3        alpine                 "/bin/sh"           21 minutes ago      Exited (0) 21 minutes ago                            test-container

So a little action plugin which will replace executable and maybe some options is very doable.

from ansible-podman-collections.

I think the easiest path depends on how the docker modules are implemented.

1. If those modules call docker CLI, then just add support for a variable that indicates the CLI program to use. Then pass that variable to the role before running.
2. If those modules call docker API, then just run podman v2 API server and add the DOCKER_HOST environment variable pointing to podman's socket before running the role.

from ansible-podman-collections.

So if you want to replace docker with podman with your collection in ansible playbooks:

How to port my playbook? https://github.com/ReinerNippes/selfhosted_on_docker

Just pulling and starting a container isn't enough. You have to provide also networking similar to docker.

Do you see any chance for this in the near future?

from ansible-podman-collections.