mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-11-16 14:54:29 +01:00
73f18fd42f
This is useful for adding extra functionality or defaults to _every_ nixos evaluation. My use case is overriding behaviour for all nixos tests, for example setting packageOverrides to newer versions and changing some default dependencies/settings. By making this accessible through an environment variable, this can now be fully accomplished externally. No more need to fork nixos/nixpkgs (which becomes a maintenance burden), just use the channel instead and plug in via this envvar.
72 lines
2.8 KiB
Nix
72 lines
2.8 KiB
Nix
# From an end-user configuration file (`configuration'), build a NixOS
|
||
# configuration object (`config') from which we can retrieve option
|
||
# values.
|
||
|
||
{ system ? builtins.currentSystem
|
||
, pkgs ? null
|
||
, baseModules ? import ../modules/module-list.nix
|
||
, extraArgs ? {}
|
||
, modules
|
||
, check ? true
|
||
, prefix ? []
|
||
}:
|
||
|
||
let extraArgs_ = extraArgs; pkgs_ = pkgs; system_ = system;
|
||
extraModules = let e = builtins.getEnv "NIXOS_EXTRA_MODULE_PATH";
|
||
in if e == "" then [] else [(import (builtins.toPath e))];
|
||
in rec {
|
||
|
||
# Merge the option definitions in all modules, forming the full
|
||
# system configuration.
|
||
inherit (pkgs.lib.evalModules {
|
||
inherit prefix;
|
||
modules = modules ++ extraModules ++ baseModules;
|
||
args = extraArgs;
|
||
check = check && options.environment.checkConfigurationOptions.value;
|
||
}) config options;
|
||
|
||
# These are the extra arguments passed to every module. In
|
||
# particular, Nixpkgs is passed through the "pkgs" argument.
|
||
# FIXME: we enable config.allowUnfree to make packages like
|
||
# nvidia-x11 available. This isn't a problem because if the user has
|
||
# ‘nixpkgs.config.allowUnfree = false’, then evaluation will fail on
|
||
# the 64-bit package anyway. However, it would be cleaner to respect
|
||
# nixpkgs.config here.
|
||
extraArgs = extraArgs_ // {
|
||
inherit pkgs modules baseModules;
|
||
modulesPath = ../modules;
|
||
pkgs_i686 = import ./nixpkgs.nix { system = "i686-linux"; config.allowUnfree = true; };
|
||
utils = import ./utils.nix pkgs;
|
||
};
|
||
|
||
# Import Nixpkgs, allowing the NixOS option nixpkgs.config to
|
||
# specify the Nixpkgs configuration (e.g., to set package options
|
||
# such as firefox.enableGeckoMediaPlayer, or to apply global
|
||
# overrides such as changing GCC throughout the system), and the
|
||
# option nixpkgs.system to override the platform type. This is
|
||
# tricky, because we have to prevent an infinite recursion: "pkgs"
|
||
# is passed as an argument to NixOS modules, but the value of "pkgs"
|
||
# depends on config.nixpkgs.config, which we get from the modules.
|
||
# So we call ourselves here with "pkgs" explicitly set to an
|
||
# instance that doesn't depend on nixpkgs.config.
|
||
pkgs =
|
||
if pkgs_ != null
|
||
then pkgs_
|
||
else import ./nixpkgs.nix (
|
||
let
|
||
system = if nixpkgsOptions.system != "" then nixpkgsOptions.system else system_;
|
||
nixpkgsOptions = (import ./eval-config.nix {
|
||
inherit system extraArgs modules prefix;
|
||
# For efficiency, leave out most NixOS modules; they don't
|
||
# define nixpkgs.config, so it's pointless to evaluate them.
|
||
baseModules = [ ../modules/misc/nixpkgs.nix ../modules/config/no-x-libs.nix ];
|
||
pkgs = import ./nixpkgs.nix { system = system_; config = {}; };
|
||
check = false;
|
||
}).config.nixpkgs;
|
||
in
|
||
{
|
||
inherit system;
|
||
inherit (nixpkgsOptions) config;
|
||
});
|
||
|
||
}
|