pkgs-by-name for flake.parts

This project provides a flake.parts module that automatically loads Nix packages from a specified directory. It transforms a directory tree containing package files suitable for callPackage into a corresponding nested attribute set of derivations.

For documentation and examples, please refer to the manual.

Installation

The structure of the directory containing the packages is the same structure as the pkgs/by-name directory from nixpkgs.

The first step is to import the input.

  inputs = {
      pkgs-by-name-for-flake-parts.url = "github:drupol/pkgs-by-name-for-flake-parts";
  };

Then, import the module:

  imports = [
      inputs.pkgs-by-name-for-flake-parts.flakeModule
  ];

Then configure the module:

  perSystem = {
      pkgsDirectory = ./nix/pkgs;
  };

Usage

Once the module is configured, it does two things:

1. It builds the Flake's packages attribute by recursively traversing the directory specified in the pkgsDirectory attribute. This directory, which may have a nested tree structure, is transformed into a flat list of packages. Each package is named by concatenating its relative directory path from pkgsDirectory to the package itself.
2. It builds the Flake's legacyPackages attribute by allowing you to access the packages using the same hierarchical structure as the package directory specified in the pkgsDirectory attribute. This means you can reference packages as if they were still organized in the original tree structure.

Configuration

This module has the following configuration attributes:

• pkgsDirectory: The directory containing the packages. This directory should contain a tree of Nix files suitable for callPackage. The default value is null.
• pkgsNameSeparator: The separator used to concatenate the package name. The default value is /.

Example

Given this flake.nix file:

{
  inputs = {
    flake-parts.url = "github:hercules-ci/flake-parts";
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    pkgs-by-name-for-flake-parts.url = "github:drupol/pkgs-by-name-for-flake-parts";
  };

  outputs = inputs@{ flake-parts, ... }: flake-parts.lib.mkFlake { inherit inputs; } {
    systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
    imports = [
      inputs.pkgs-by-name-for-flake-parts.flakeModule
    ];
    perSystem = { ... }: {
      pkgsDirectory = ./nix/pkgs-by-name;
    };
  };
}

In this given directory structure:

/flake.lock
/flake.nix
/nix
└── pkgs-by-name
    ├── a
    │   └── package.nix
    └── b
        └── c
            └── package.nix

The content of the package.nix files is not important, but they should be suitable for callPackage. In this example, both files contains: { hello }: hello.

The following REPL session demonstrates how to access the discovered packages:

❯ nix repl
Nix 2.24.8
nix-repl> :lf .
Added 18 variables.

nix-repl> outputs.legacyPackages.x86_64-linux.a
«derivation /nix/store/af3rc6phyv80h7aq4y3d08awnq2ja8fp-hello-2.12.1.drv»

nix-repl> outputs.packages.x86_64-linux.a
«derivation /nix/store/af3rc6phyv80h7aq4y3d08awnq2ja8fp-hello-2.12.1.drv»

nix-repl> outputs.legacyPackages.x86_64-linux.b.c
«derivation /nix/store/af3rc6phyv80h7aq4y3d08awnq2ja8fp-hello-2.12.1.drv»

nix-repl> outputs.packages.x86_64-linux."b/c"
«derivation /nix/store/af3rc6phyv80h7aq4y3d08awnq2ja8fp-hello-2.12.1.drv»