guilloteauq / nix-shell-container

A nix shell running in a (thin) container

Nix-shell-container

A nix shell running in a (thin) container

Warnings

This project is just a pretext to play with containers.

Don't expect it to work perfectly :)

Demo

Use

Import this flake:

# ...
inputs.nsc.url = "github:GuilloteauQ/nix-shell-container";
# ...

(feel free to make the nixpkgs input of this flake follow yours)

Now when defining a shell use nsc.lib.mkShell

# ...
devShells.${system} = {
    myshell = nsc.lib.mkShell {
        # Your normal nix shell thingies
    };
};
# ...

By default, this function behaves like the usual mkShell.

You can activate the containerization by adding setting the argument containerize to true in the mkShell:

# ...
devShells.${system} = {
    myshell = nsc.lib.mkShell {
        containerize = true;
        # Your normal nix shell thingies
    };
};
# ...

Now running nix develop .#myshell will get you in a container with the shell environment!

(you might need to run it with sudo if the unprivileged user namespace are not available on your machine)

Pass commands

It is not possible to pass commands to the shell via nix develop .#myshell --command ... because of the way Nix manages the --command flag (see here).

The solution is to use the container shell as a package:

packages.${system} = {
    myenv = nsc.lib.mkShellContainer {
        # Your normal nix shell thingies
    };
};

To enter the container, you can run nix run .#myenv.

To execute commands in the container, you can run nix run .#myenv -- COMMAND.

Misc

The container wrapper is written in Go, and it based on the amazing talk of Liz Rice: https://www.youtube.com/watch?v=8fi7uSYlOdc