nixpkgs/nixos/modules/installer/tools/tools.nix

# This module generates nixos-install, nixos-rebuild,
# nixos-generate-config, etc.

{ config, pkgs, modulesPath, ... }:

let

  cfg = config.installer;

  makeProg = args: pkgs.substituteAll (args // {
    dir = "bin";
    isExecutable = true;
  });

  nixos-build-vms = makeProg {
    name = "nixos-build-vms";
    src = ./nixos-build-vms/nixos-build-vms.sh;
  };

  nixos-install = makeProg {
    name = "nixos-install";
    src = ./nixos-install.sh;

    inherit (pkgs) perl pathsFromGraph;
    nix = config.nix.package;

    nixClosure = pkgs.runCommand "closure"
      { exportReferencesGraph = ["refs" config.nix.package]; }
      "cp refs $out";
  };

  nixos-rebuild = makeProg {
    name = "nixos-rebuild";
    src = ./nixos-rebuild.sh;
    nix = config.nix.package;
  };

  nixos-generate-config = makeProg {
    name = "nixos-generate-config";
    src = ./nixos-generate-config.pl;
    path = [ pkgs.btrfsProgs ];
    perl = "${pkgs.perl}/bin/perl -I${pkgs.perlPackages.FileSlurp}/lib/perl5/site_perl";
  };

  nixos-option = makeProg {
    name = "nixos-option";
    src = ./nixos-option.sh;
  };

  nixos-version = makeProg {
    name = "nixos-version";
    src = ./nixos-version.sh;
    inherit (config.system) nixosVersion nixosCodeName nixosRevision;
  };

in

{
  config = {
    environment.systemPackages =
      [ nixos-build-vms
        nixos-install
        nixos-rebuild
        nixos-generate-config
        nixos-option
        nixos-version
      ];

    system.build = {
      inherit nixos-install nixos-generate-config nixos-option nixos-rebuild;
    };
  };
}