flk/doc/outputs/modules.md

Modules

The modules directory is a replica of nixpkg's NixOS modules , and follows the same semantics. This allows for trivial upstreaming into nixpkgs proper once your module is sufficiently stable.

All modules linked in module-list.nix are automatically exported via nixosModules.<file-basename>, and imported into all hosts.

Note:

This is reserved for declaring brand new module options. If you just want to declare a coherent configuration of already existing and related NixOS options , use profiles instead.

Semantics

In case you've never written a module for nixpkgs before, here is a brief outline of the process.

Declaration

modules/services/service-category/my-service.nix:

{ config, lib, ... }:
let
  cfg = config.services.myService;
in
{
  options.services.myService = {
    enable = lib.mkEnableOption "Description of my new service.";

    # additional options ...
  };

  config = lib.mkIf cfg.enable {
    # implementation ...
  };
}

Import

modules/module-list.nix:

[
  ./services/service-category/my-service.nix
]

Usage

Internal

profiles/profile-category/my-profile.nix:

{ ... }:
{
  services.MyService.enable = true;
}

External

flake.nix:

{
  # inputs omitted

  outputs = { self, devos, nixpkgs, ... }: {
    nixosConfigurations.myConfig = nixpkgs.lib.nixosSystem {
      system = "...";

      modules = [
        devos.nixosModules.my-service
        ({ ... }: {
          services.MyService.enable = true;
        })
      ];
    };
  };
}