[Cyph0n]

I recently migrated over to NixOS which treats systemd as the source of truth for everything, including containers. I found this model extremely intuitive, but it was difficult to apply this to Docker Compose without a lot of manual migration. So I ended up writing a tool that handles this for you — it converts your Compose files into a NixOS config that can be interpreted and managed natively.

https://github.com/aksiksi/compose2nix

[jay-aye-see-key]

This is a cool idea. Two questions:

Arion can wrap docker-compose and run as a project or part of a nixos config. Did you come across Arion before creating this, and have you compared them?

I had a brief look through your examples and it doesn’t look like compose2nix implements docker-compose’s network per compose file. Is this something you want to add?

[Cyph0n]

So, from what I understand, arion provides a Nix frontend for Docker Compose. This allows you to write Nix that runs via Docker Compose. It doesn’t solve the migration problem: if you have an existing Docker Compose project, you still need to manually convert it into Nix for arion to consume.

My tool does the opposite: it takes a Compose file and converts it into OCI containers in Nix. The idea is that your Compose file is the source of truth, and you simply generate Nix to run on NixOS. One benefit here is that you can easily migrate an existing Compose project into native Docker/Podman containers running on NixOS. This removes Docker Compose from the equation entirely - essentially a “reimplementation” of Compose.

It should support the default network per Compose project. See: https://github.com/aksiksi/compose2nix/blob/6dc451fd960f7a9b.... If you’re talking about something else, please feel free to open an issue and I can take a look.