nix-module-discovery

Automatically discover and import Nix modules from a directory tree, where the
layout encodes each module's class.

It exposes its functionality two ways:

• lib — pure functions (flake.lib) you can call directly, with no
  dependency on flake-parts.
• flake-parts module — flakeModules.default, which wires discovered
  modules into flake.modules.<class>.<name> for you.

Layout

modules/
  <class>/                 # e.g. nixos, homeManager
    <name>.nix             # a single-file module
    <name>/                # a multi-file module: every *.nix beneath it
      *.nix                # (recursively) is merged into one module via imports

Each discovered module is stamped with _class and _file. The class and
module names are the directory/file names verbatim; use transform to rewrite
them (e.g. home_manager -> homeManager) or edit the module.

Usage (flake-parts module)

{
  inputs = {
    flake-parts.url = "github:hercules-ci/flake-parts";
    nix-module-discovery.url = "github:jtrrll/nix-module-discovery";
  };

  outputs = inputs@{ flake-parts, nix-module-discovery, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      imports = [ nix-module-discovery.flakeModules.default ];
      systems = [ "x86_64-linux" ];

      moduleDiscovery.path = ./modules;
    };
}

Given the layout above, this populates:

• flake.modules.nixos.<name>
• flake.modules.homeManager.<name>

Options

• moduleDiscovery.path (path) — directory to scan.
• moduleDiscovery.transform (class -> name -> module -> { class, name, module })
  — receives the raw class, raw name, and built module; returns the final class
  key, attribute name, and module. May remap the class, rename the module, or
  edit it. Default: identity.

Usage (library)

The pure functions are exposed under flake.lib, usable without flake-parts:

{
  inputs.nix-module-discovery.url = "github:jtrrll/nix-module-discovery";

  outputs = { nix-module-discovery, ... }:
    let
      modules = nix-module-discovery.lib.modulesByClassAndName { path = ./modules; };
    in
    { /* modules == { <class>.<name> = <module>; ... } */ };
}

• modulesByClassAndName { path, transform ? ... } — transform returns { class, name, module }
• nixFilesInDir { path, recurse ? false }