enable nix run

[archite]

Is there a reason why something like this is not done so that nix run .#nixosConfigurations.myhostname.config.system.build.diskoNoDeps could setup disks prior to nixos-install --flake .#myhostname? This saves running build and then the result script.

Great work. Thanks for your effort.

[Mic92]

Currently was mainly used by the disko cli (which might be also need to be fixed as a result of this)

[Mic92]

This line needs to be fixed as well:

disko/disko

Line 124 in 935feb7

exec "$script"

[archite]

Looking at it, it only looks like this change would affect the nixosModule. I've been using this in my flake outputs as a workaround but not ideal.

apps = forAllSystems (system: let
  pkgs = nixpkgs.legacyPackages.${system};
  hosts = pkgs.lib.filterAttrs (_: value:
    value.pkgs.system == system &&
    builtins.hasAttr "diskoNoDeps" value.config.system.build
  ) self.nixosConfigurations;
in
  if (hosts == {}) then {} else {
  disko = pkgs.lib.genAttrs (builtins.attrNames hosts) (name:
    {
      program = "${self.nixosConfigurations.${name}.config.system.build.diskoNoDeps}";
      type = "app";
    });
  }
);

[iFreilicht]

This change makes disko incompatible with nixos-anywhere, which calls the script directly.

That's a solvable problem, but I don't see much use in changing this now. These scripts are not supposed to be called directly by a user anyway. Unless there's a good reason to get this change merged, I'd vote for closing this PR.

[Enzime]

As someone who doesn't use the disko CLI, I personally would like the ability to run nix run github:Enzime/dotfiles-nix#nixosConfigurations.host.config.system.build.formatScript, this would make it super easy to execute from a NixOS live installer for example

[iFreilicht]

Okay good to know, thank you. I'm concerned about backwards compatibility, what could we do so we don't break compatibility with nixos-anywhere? Maybe we should submit a PR to them that detects if formatScript is a file or folder and then executes either formatScript or formatScript/bin/format?

[Enzime]

I think the actual root cause is that nix run should support executing executable files, rather than forcing all of them to follow the structure bin/<meta.mainProgram>

But that would probably be the easiest solution

cc @Mic92 with his nixos-anywhere maintainer hat on

[iFreilicht]

How easy is it right now to get PRs merged in NixCpp? Haven't followed the development for a while, but this would be relatively simple to implement. Just add some additional logic here: https://github.com/NixOS/nix/blob/68ba6ff4709d936c1a714de35da08f8ed354c710/src/nix/app.cc#L118

[Mic92]

If we switch to this, we should make new attributes and make the old "script" ones execute those with a warning using lib.warn. This would give us time to migrate tools like nixos-anywhere.

[Mic92]

Also diskoNoDeps is the only thing used by nixos-anywhere, we still have nixpkgs with the old disko cli around.

[Mic92]

Maybe something like:

• diskoFormat, diskoMount, diskoRecreate, diskoRecreateNoDeps

[Enzime]

@iFreilicht I think a simple PR for nix run could get through pretty quickly if you update docs and tests