I need to generate a number of scripts in my configuration and make them into a single package (for ease of reference, because there are a lot of them).

So far, I’m creating the scripts via writeShellApplication, making them into packages via an overlay, merging them with buildEnv and then adding the resulting package to `systemPackages.

Something like:

nixpkgs.overlays = [ (final: prev: {
  my-hello-1 = final.writeShellApplication {
    name = "my-hello-1-script";
    text = "echo my hello wolrd 1";
  };
  my-hello-2 = final.writeShellApplication {
    name = "my-hello-2-script";
    text = "echo my hello wolrd 1";
  };
  my-hello-scripts = final.buildEnv {
    name = "my-hello-scripts";
    paths = [ final.my-hello-1 final.my-hello-2 ];
  };
}) ];

environment.systemPackages = [ pkgs.my-hello-scripts ];

This works, but I don’t really need the my-hello-1 and my-hello-2 packages… can you think of a way to make do without needing them?

  • Atemu
    6·
    1 year ago

    Why the overlay? If you just want to give the drvs names (good practice IMO), simply use a let binding.

    The buildEnv is unnecessary: systemPackages does the same with all the derivations in the list in the end anyways.

    • gompOP
      2·
      1 year ago

      If you just want to give the drvs names […], simply use a let binding.

      I must be missing something here… my first idea was to put all the writeShellApplications inside systemPackages (with no let bindings: the scripts are generated from config anyway), but it resulted in nixos complaining that it was expecting actual packages.

      Edit: scratch that - I was being stupid :)

    • gompOP
      1·
      1 year ago

      Well, it does work as-is, and it’s not like I’m worried how many symlinks need to be dereerenced… the point is mainly that my nix code could be much simpler if I didn’t have to build the overlay attrset like that from a list.

      • hallettj@beehaw.orgEnglish
        1·
        1 year ago

        You might simplify it a bit with something like,

        let my-hello-scripts = [
  (writeShellApplication {
    name = "my-hello-1-script";
    text = "echo my hello world 1";
  })
  (writeShellApplication {
    name = "my-hello-2-script";
    text = "echo my hello world 2";
  })
];
in
{
  environment.systemPackages = 
    my-hello-scripts ++
    [ pkgs.whatever-else-you-want ];
}
        • gompOP
          2·
          1 year ago

          That was my first idea (well, I say “my”… but it was really suggested by yourself in the question I posted the other day), but it results in nixos complaining that error: A definition for option 'environment.systemPackages."[definition 1-entry 1]"' is not of type 'package'.

          It might very well be that I’m doing some stupid mistake here (or maybe it’s something that used to work and doesn’t anymore?)… here’s what I used to test it out:

            environment.systemPackages = [
    pkgs.writeShellApplication {
      name = "some-script";
      text = "echo hello wolrd";
    }
  ];

          Edit:

          And indeed I was the one doing stupid things: it must be

            environment.systemPackages = [
    (pkgs.writeShellApplication {
      name = "some-script";
      text = "echo hello wolrd";
    })
  ];

          with the parentheses, or it’s a list with two elements (a function and an attrset)…