Act: Support other container runtimes

[lwille]

I couldn't find anybody pointing out the missing support for container runtimes other than Docker, so here I go:

As a user of Fedora Silverblue, I don't have out-of-the-box docker builtin with my OS, but instead podman (a daemonless and "rootless" userspace container engine).
For purposes of building images and running containers it's directly compatible with docker, however as it doesn't have a daemon, there's no way to interact with it using go docker bindings (like act does).

From what I understand, act uses docker bindings in order to

• resolve and pull images
• create and execute containers

All of this is possible with podman as well, so a solution could be to replace the direct docker bindings with an abstraction layer that would default to docker, but allows the user to select podman (or another binding) to interact with containers or images.
I would be interested in helping to get this to work, and want to raise this issue to ask for support on this topic.

[ianwalter]

But GitHub Actions don't support other container runtimes do they?

[lwille]

Honestly I don't know what runtimes they're using. They're talking about "docker actions" in the docs, but as the actions spec only exposes very superficial parts of the underlying system it could really be anything.

As both docker and podman use the same kind of image specification, images are compatible with both and other runtimes.

From my POV, there's no strong requirement to lock in with docker for the sake of running actions locally or in CI.

A daemonless container runtime could even be beneficial for environments where users don't have enough access rights on their machine to install or control a docker daemon (think CI or corporate environments).

[likern]

It's a big pain point to use Docker on Fedora 32.
It's not supported out of the box.

[github-actions[bot]]

Issue is stale and will be closed in 7 days unless there is new activity