nixpkgs/nixos/lib/eval-config.nix
2015-03-15 14:45:42 +01:00

64 lines
2.2 KiB
Nix
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# From an end-user configuration file (`configuration'), build a NixOS
# configuration object (`config') from which we can retrieve option
# values.
# !!! Please think twice before adding to this argument list!
# Ideally eval-config.nix would be an extremely thin wrapper
# around lib.evalModules, so that modular systems that have nixos configs
# as subcomponents (e.g. the container feature, or nixops if network
# expressions are ever made modular at the top level) can just use
# types.submodule instead of using eval-config.nix
{ # !!! system can be set modularly, would be nice to remove
system ? builtins.currentSystem
, # !!! is this argument needed any more? The pkgs argument can
# be set modularly anyway.
pkgs ? null
, # !!! what do we gain by making this configurable?
baseModules ? import ../modules/module-list.nix
, # !!! See comment about args in lib/modules.nix
extraArgs ? {}
, modules
, # !!! See comment about check in lib/modules.nix
check ? true
, prefix ? []
, lib ? import ../../lib
}:
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
let
pkgsModule = rec {
_file = ./eval-config.nix;
key = _file;
config = {
nixpkgs.system = lib.mkDefault system_;
_module.args.pkgs = lib.mkIf (pkgs_ != null) (lib.mkForce pkgs_);
};
};
in rec {
# Merge the option definitions in all modules, forming the full
# system configuration.
inherit (lib.evalModules {
inherit prefix check;
modules = modules ++ extraModules ++ baseModules ++ [ pkgsModule ];
args = extraArgs;
}) 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 modules baseModules;
};
inherit (config._module.args) pkgs;
}