diff --git a/flake.nix b/flake.nix index bb76fae486d5..29dffa9fa4e4 100644 --- a/flake.nix +++ b/flake.nix @@ -18,6 +18,9 @@ in { lib = lib.extend (final: prev: { + + nixos = import ./nixos/lib { lib = final; }; + nixosSystem = { modules, ... } @ args: import ./nixos/lib/eval-config.nix (args // { modules = diff --git a/nixos/lib/default.nix b/nixos/lib/default.nix new file mode 100644 index 000000000000..2b3056e01457 --- /dev/null +++ b/nixos/lib/default.nix @@ -0,0 +1,33 @@ +let + # The warning is in a top-level let binding so it is only printed once. + minimalModulesWarning = warn "lib.nixos.evalModules is experimental and subject to change. See nixos/lib/default.nix" null; + inherit (nonExtendedLib) warn; + nonExtendedLib = import ../../lib; +in +{ # Optional. Allows an extended `lib` to be used instead of the regular Nixpkgs lib. + lib ? nonExtendedLib, + + # Feature flags allow you to opt in to unfinished code. These may change some + # behavior or disable warnings. + featureFlags ? {}, + + # This file itself is rather new, so we accept unknown parameters to be forward + # compatible. This is generally not recommended, because typos go undetected. + ... +}: +let + seqIf = cond: if cond then builtins.seq else a: b: b; + # If cond, force `a` before returning any attr + seqAttrsIf = cond: a: lib.mapAttrs (_: v: seqIf cond a v); + + eval-config-minimal = import ./eval-config-minimal.nix { inherit lib; }; +in +/* + This attribute set appears as lib.nixos in the flake, or can be imported + using a binding like `nixosLib = import (nixpkgs + "/nixos/lib") { }`. +*/ +{ + inherit (seqAttrsIf (!featureFlags?minimalModules) minimalModulesWarning eval-config-minimal) + evalModules + ; +} diff --git a/nixos/lib/eval-config-minimal.nix b/nixos/lib/eval-config-minimal.nix new file mode 100644 index 000000000000..d45b9ffd4261 --- /dev/null +++ b/nixos/lib/eval-config-minimal.nix @@ -0,0 +1,49 @@ + +# DO NOT IMPORT. Use nixpkgsFlake.lib.nixos, or import (nixpkgs + "/nixos/lib") +{ lib }: # read -^ + +let + + /* + Invoke NixOS. Unlike traditional NixOS, this does not include all modules. + Any such modules have to be explicitly added via the `modules` parameter, + or imported using `imports` in a module. + + A minimal module list improves NixOS evaluation performance and allows + modules to be independently usable, supporting new use cases. + + Parameters: + + modules: A list of modules that constitute the configuration. + + specialArgs: An attribute set of module arguments. Unlike + `config._module.args`, these are available for use in + `imports`. + `config._module.args` should be preferred when possible. + + Return: + + An attribute set containing `config.system.build.toplevel` among other + attributes. See `lib.evalModules` in the Nixpkgs library. + + */ + evalModules = { + prefix ? [], + modules ? [], + specialArgs ? {}, + }: + # NOTE: Regular NixOS currently does use this function! Don't break it! + # Ideally we don't diverge, unless we learn that we should. + # In other words, only the public interface of nixos.evalModules + # is experimental. + lib.evalModules { + inherit prefix modules; + specialArgs = { + modulesPath = builtins.toString ../modules; + } // specialArgs; + }; + +in +{ + inherit evalModules; +} diff --git a/nixos/lib/eval-config.nix b/nixos/lib/eval-config.nix index 00e58e24e926..e3eb88a60eba 100644 --- a/nixos/lib/eval-config.nix +++ b/nixos/lib/eval-config.nix @@ -33,6 +33,12 @@ let pkgs_ = pkgs; in let + evalModulesMinimal = (import ./default.nix { + inherit lib; + # Implicit use of feature is noted in implementation. + featureFlags.minimalModules = { }; + }).evalModules; + pkgsModule = rec { _file = ./eval-config.nix; key = _file; @@ -70,11 +76,9 @@ let }; allUserModules = modules ++ legacyModules; - noUserModules = lib.evalModules ({ - inherit prefix; + noUserModules = evalModulesMinimal ({ + inherit prefix specialArgs; modules = baseModules ++ extraModules ++ [ pkgsModule modulesModule ]; - specialArgs = - { modulesPath = builtins.toString ../modules; } // specialArgs; }); # Extra arguments that are useful for constructing a similar configuration. diff --git a/nixos/modules/misc/nixpkgs.nix b/nixos/modules/misc/nixpkgs.nix index 2e0c8e4cf2c4..69967c8a7601 100644 --- a/nixos/modules/misc/nixpkgs.nix +++ b/nixos/modules/misc/nixpkgs.nix @@ -64,6 +64,11 @@ let in { + imports = [ + ./assertions.nix + ./meta.nix + ]; + options.nixpkgs = { pkgs = mkOption { diff --git a/nixos/modules/misc/nixpkgs/test.nix b/nixos/modules/misc/nixpkgs/test.nix new file mode 100644 index 000000000000..ec5fab9fb4a5 --- /dev/null +++ b/nixos/modules/misc/nixpkgs/test.nix @@ -0,0 +1,8 @@ +{ evalMinimalConfig, pkgs, lib, stdenv }: +lib.recurseIntoAttrs { + invokeNixpkgsSimple = + (evalMinimalConfig ({ config, modulesPath, ... }: { + imports = [ (modulesPath + "/misc/nixpkgs.nix") ]; + nixpkgs.system = stdenv.hostPlatform.system; + }))._module.args.pkgs.hello; +} diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix index b2f223e7ccdc..6e66e9cbe96d 100644 --- a/nixos/tests/all-tests.nix +++ b/nixos/tests/all-tests.nix @@ -19,6 +19,13 @@ let handleTestOn = systems: path: args: if elem system systems then handleTest path args else {}; + + nixosLib = import ../lib { + # Experimental features need testing too, but there's no point in warning + # about it, so we enable the feature flag. + featureFlags.minimalModules = {}; + }; + evalMinimalConfig = module: nixosLib.evalModules { modules = [ module ]; }; in { _3proxy = handleTest ./3proxy.nix {}; @@ -331,6 +338,7 @@ in nix-serve-ssh = handleTest ./nix-serve-ssh.nix {}; nixops = handleTest ./nixops/default.nix {}; nixos-generate-config = handleTest ./nixos-generate-config.nix {}; + nixpkgs = pkgs.callPackage ../modules/misc/nixpkgs/test.nix { inherit evalMinimalConfig; }; node-red = handleTest ./node-red.nix {}; nomad = handleTest ./nomad.nix {}; novacomd = handleTestOn ["x86_64-linux"] ./novacomd.nix {};