vic / fp-nm-ws

A flake-parts module to access per-system module arguments inside nixos-modules.

fp-nm-ws: FlakeParts NixosModule WithSystem'

This flake provides a flake-parts module that allows nixos-modules to access perSystem module parameters without having to rely on global variables.

Mixing the provided nixosModules.default module, will provide you with withSystem', self', and inputs' to your other nixos modules.

Example Usage

# flake.nix
{
  inputs.flake-parts.url = "github:hercules-ci/flake-parts";
  inputs.fp-nm-ws.url = "github:vic/fp-nm-ws";
  outputs = inputs: inputs.flake-parts.lib.mkFlake { inherit inputs; } ./your-flake-module.nix;
}

# your-flake-module.nix
{inputs, ...}: {
  perSystem = {system, ...}: {
    config._module.args.foo = "moo-${system}"; # suppose you have a per-system module argument named foo.
    options.bar.default = "some per-system option";
  };

  flake.nixosModules.your-nixos-module.imports = [
    inputs.fp-nm-ws.nixosModules.default # mix-in along with your nixos module.
    ./your-nixos-module.nix
  ];

}

# your-nixos-module.nix
{ config, lib, withSystem', inputs', ...}: {

  # an example usage is reusing the same nixpkgs instance.
  nixpkgs.pkgs = inputs'.nixpkgs.legacyPackages;

  accessFoo = withSystem' ({foo, ...}: foo); # use named parameters
  accessBar = withSystem' (sys@{config, ...}: sys.config.bar);

}