pyrox.dev
1# From an end-user configuration file (`configuration.nix'), build a NixOS
2# configuration object (`config') from which we can retrieve option
3# values.
4
5# !!! Please think twice before adding to this argument list!
6# Ideally eval-config.nix would be an extremely thin wrapper
7# around lib.evalModules, so that modular systems that have nixos configs
8# as subcomponents (e.g. the container feature, or nixops if network
9# expressions are ever made modular at the top level) can just use
10# types.submodule instead of using eval-config.nix
11evalConfigArgs@
12{ # !!! system can be set modularly, would be nice to remove,
13 # however, removing or changing this default is too much
14 # of a breaking change. To set it modularly, pass `null`.
15 system ? builtins.currentSystem
16, # !!! is this argument needed any more? The pkgs argument can
17 # be set modularly anyway.
18 pkgs ? null
19, # !!! what do we gain by making this configurable?
20 # we can add modules that are included in specialisations, regardless
21 # of inheritParentConfig.
22 baseModules ? import ../modules/module-list.nix
23, # !!! See comment about args in lib/modules.nix
24 extraArgs ? {}
25, # !!! See comment about args in lib/modules.nix
26 specialArgs ? {}
27, modules
28, modulesLocation ? (builtins.unsafeGetAttrPos "modules" evalConfigArgs).file or null
29, # !!! See comment about check in lib/modules.nix
30 check ? true
31, prefix ? []
32, lib ? import ../../lib
33, extraModules ? let e = builtins.getEnv "NIXOS_EXTRA_MODULE_PATH";
34 in if e == "" then [] else [(import e)]
35}:
36
37let pkgs_ = pkgs;
38in
39
40let
41 evalModulesMinimal = (import ./default.nix {
42 inherit lib;
43 # Implicit use of feature is noted in implementation.
44 featureFlags.minimalModules = { };
45 }).evalModules;
46
47 pkgsModule = rec {
48 _file = ./eval-config.nix;
49 key = _file;
50 config = {
51 # Explicit `nixpkgs.system` or `nixpkgs.localSystem` should override
52 # this. Since the latter defaults to the former, the former should
53 # default to the argument. That way this new default could propagate all
54 # they way through, but has the last priority behind everything else.
55 nixpkgs.system = lib.mkIf (system != null) (lib.mkDefault system);
56
57 _module.args.pkgs = lib.mkIf (pkgs_ != null) (lib.mkForce pkgs_);
58 };
59 };
60
61 withWarnings = x:
62 lib.warnIf (evalConfigArgs?extraArgs) "The extraArgs argument to eval-config.nix is deprecated. Please set config._module.args instead."
63 lib.warnIf (evalConfigArgs?check) "The check argument to eval-config.nix is deprecated. Please set config._module.check instead."
64 x;
65
66 legacyModules =
67 lib.optional (evalConfigArgs?extraArgs) {
68 config = {
69 _module.args = extraArgs;
70 };
71 }
72 ++ lib.optional (evalConfigArgs?check) {
73 config = {
74 _module.check = lib.mkDefault check;
75 };
76 };
77
78 allUserModules =
79 let
80 # Add the invoking file (or specified modulesLocation) as error message location
81 # for modules that don't have their own locations; presumably inline modules.
82 locatedModules =
83 if modulesLocation == null then
84 modules
85 else
86 map (lib.setDefaultModuleLocation modulesLocation) modules;
87 in
88 locatedModules ++ legacyModules;
89
90 noUserModules = evalModulesMinimal ({
91 inherit prefix specialArgs;
92 modules = baseModules ++ extraModules ++ [ pkgsModule modulesModule ];
93 });
94
95 # Extra arguments that are useful for constructing a similar configuration.
96 modulesModule = {
97 config = {
98 _module.args = {
99 inherit noUserModules baseModules extraModules modules;
100 };
101 };
102 };
103
104 nixosWithUserModules = noUserModules.extendModules { modules = allUserModules; };
105
106in
107withWarnings nixosWithUserModules // {
108 inherit extraArgs;
109 inherit (nixosWithUserModules._module.args) pkgs;
110}