From c9fea8c03cd76c841392feb69b7f6d37f527399e Mon Sep 17 00:00:00 2001 From: Robert Hensing Date: Tue, 14 Jun 2022 22:34:16 +0200 Subject: [PATCH] nixos: Add simplified nixpkgs.{hostSystem,buildSystem} --- nixos/modules/misc/nixpkgs.nix | 108 +++++++++++++++++++++++++--- nixos/modules/misc/nixpkgs/test.nix | 61 +++++++++++++++- 2 files changed, 158 insertions(+), 11 deletions(-) diff --git a/nixos/modules/misc/nixpkgs.nix b/nixos/modules/misc/nixpkgs.nix index 866bb3516009..132a9b68ceb4 100644 --- a/nixos/modules/misc/nixpkgs.nix +++ b/nixos/modules/misc/nixpkgs.nix @@ -55,9 +55,46 @@ let check = builtins.isAttrs; }; - defaultPkgs = import ../../.. { - inherit (cfg) config overlays localSystem crossSystem; - }; + hasBuildPlatform = opt.buildPlatform.highestPrio < (mkOptionDefault {}).priority; + hasHostPlatform = opt.hostPlatform.isDefined; + hasPlatform = hasHostPlatform || hasBuildPlatform; + + # Context for messages + hostPlatformLine = optionalString hasHostPlatform "${showOptionWithDefLocs opt.hostPlatform}"; + buildPlatformLine = optionalString hasBuildPlatform "${showOptionWithDefLocs opt.buildPlatform}"; + platformLines = optionalString hasPlatform '' + Your system configuration configures nixpkgs with platform parameters: + ${hostPlatformLine + }${buildPlatformLine + }''; + + legacyOptionsDefined = + optional opt.system.isDefined opt.system + ++ (optional (opt.localSystem.highestPrio < (mkOptionDefault {}).priority) opt.localSystem) + ++ (optional (opt.crossSystem.highestPrio < (mkOptionDefault {}).priority) opt.crossSystem) + ; + + defaultPkgs = + if opt.hostPlatform.isDefined + then + let isCross = cfg.buildPlatform != cfg.hostPlatform; + systemArgs = + if isCross + then { + localSystem = cfg.buildPlatform; + crossSystem = cfg.hostPlatform; + } + else { + localSystem = cfg.hostPlatform; + }; + in + import ../../.. ({ + inherit (cfg) config overlays; + } // systemArgs) + else + import ../../.. { + inherit (cfg) config overlays localSystem crossSystem; + }; finalPkgs = if opt.pkgs.isDefined then cfg.pkgs.appendOverlays cfg.overlays else defaultPkgs; @@ -157,6 +194,46 @@ in ''; }; + hostPlatform = mkOption { + type = types.either types.str types.attrs; # TODO utilize lib.systems.parsedPlatform + example = { system = "aarch64-linux"; config = "aarch64-unknown-linux-gnu"; }; + # Make sure that the final value has all fields for sake of other modules + # referring to this. TODO make `lib.systems` itself use the module system. + apply = lib.systems.elaborate; + defaultText = literalExpression + ''(import "''${nixos}/../lib").lib.systems.examples.aarch64-multiplatform''; + description = '' + Specifies the platform where the NixOS configuration will run. + + To cross-compile, set also nixpkgs.buildPlatform. + + Ignored when nixpkgs.pkgs is set. + ''; + }; + + buildPlatform = mkOption { + type = types.either types.str types.attrs; # TODO utilize lib.systems.parsedPlatform + default = cfg.hostPlatform; + example = { system = "x86_64-linux"; config = "x86_64-unknown-linux-gnu"; }; + # Make sure that the final value has all fields for sake of other modules + # referring to this. + apply = lib.systems.elaborate; + defaultText = literalExpression + ''config.nixpkgs.hostPlatform''; + description = '' + Specifies the platform on which NixOS should be built. + By default, NixOS is built on the system where it runs, but you can + change where it's built. Setting this option will cause NixOS to be + cross-compiled. + + For instance, if you're doing distributed multi-platform deployment, + or if you're building machines, you can set this to match your + development system and/or build farm. + + Ignored when nixpkgs.pkgs is set. + ''; + }; + localSystem = mkOption { type = types.attrs; # TODO utilize lib.systems.parsedPlatform default = { inherit (cfg) system; }; @@ -176,10 +253,13 @@ in deployment, or when building virtual machines. See its description in the Nixpkgs manual for more details. - Ignored when nixpkgs.pkgs is set. + Ignored when nixpkgs.pkgs or hostPlatform is set. ''; }; + # TODO deprecate. "crossSystem" is a nonsense identifier, because "cross" + # is a relation between at least 2 systems in the context of a + # specific build step, not a single system. crossSystem = mkOption { type = types.nullOr types.attrs; # TODO utilize lib.systems.parsedPlatform default = null; @@ -193,7 +273,7 @@ in should be set as null, the default. See its description in the Nixpkgs manual for more details. - Ignored when nixpkgs.pkgs is set. + Ignored when nixpkgs.pkgs or hostPlatform is set. ''; }; @@ -216,8 +296,7 @@ in See nixpkgs.localSystem for more information. - Ignored when nixpkgs.localSystem is set. - Ignored when nixpkgs.pkgs is set. + Ignored when nixpkgs.pkgs, nixpkgs.localSystem or nixpkgs.hostPlatform is set. ''; }; }; @@ -240,10 +319,23 @@ in else "nixpkgs.localSystem"; pkgsSystem = finalPkgs.stdenv.targetPlatform.system; in { - assertion = nixosExpectedSystem == pkgsSystem; + assertion = !hasPlatform -> nixosExpectedSystem == pkgsSystem; message = "The NixOS nixpkgs.pkgs option was set to a Nixpkgs invocation that compiles to target system ${pkgsSystem} but NixOS was configured for system ${nixosExpectedSystem} via NixOS option ${nixosOption}. The NixOS system settings must match the Nixpkgs target system."; } ) + { + assertion = hasPlatform -> legacyOptionsDefined == []; + message = '' + Your system configures nixpkgs with the platform parameter${optionalString hasBuildPlatform "s"}: + ${hostPlatformLine + }${buildPlatformLine + } + However, it also defines the legacy options: + ${concatMapStrings showOptionWithDefLocs legacyOptionsDefined} + For a future proof system configuration, we recommend to remove + the legacy definitions. + ''; + } ]; }; diff --git a/nixos/modules/misc/nixpkgs/test.nix b/nixos/modules/misc/nixpkgs/test.nix index ec5fab9fb4a5..9e8851707f8f 100644 --- a/nixos/modules/misc/nixpkgs/test.nix +++ b/nixos/modules/misc/nixpkgs/test.nix @@ -1,8 +1,63 @@ { evalMinimalConfig, pkgs, lib, stdenv }: +let + eval = mod: evalMinimalConfig { + imports = [ ../nixpkgs.nix mod ]; + }; + withHost = eval { + nixpkgs.hostPlatform = "aarch64-linux"; + }; + withHostAndBuild = eval { + nixpkgs.hostPlatform = "aarch64-linux"; + nixpkgs.buildPlatform = "aarch64-darwin"; + }; + ambiguous = { + _file = "ambiguous.nix"; + nixpkgs.hostPlatform = "aarch64-linux"; + nixpkgs.buildPlatform = "aarch64-darwin"; + nixpkgs.system = "x86_64-linux"; + nixpkgs.localSystem.system = "x86_64-darwin"; + nixpkgs.crossSystem.system = "i686-linux"; + imports = [ + { _file = "repeat.nix"; + nixpkgs.hostPlatform = "aarch64-linux"; + } + ]; + }; + getErrors = module: + let + uncheckedEval = lib.evalModules { modules = [ ../nixpkgs.nix module ]; }; + in map (ass: ass.message) (lib.filter (ass: !ass.assertion) uncheckedEval.config.assertions); +in lib.recurseIntoAttrs { invokeNixpkgsSimple = - (evalMinimalConfig ({ config, modulesPath, ... }: { - imports = [ (modulesPath + "/misc/nixpkgs.nix") ]; + (eval { nixpkgs.system = stdenv.hostPlatform.system; - }))._module.args.pkgs.hello; + })._module.args.pkgs.hello; + assertions = + assert withHost._module.args.pkgs.stdenv.hostPlatform.system == "aarch64-linux"; + assert withHost._module.args.pkgs.stdenv.buildPlatform.system == "aarch64-linux"; + assert withHostAndBuild._module.args.pkgs.stdenv.hostPlatform.system == "aarch64-linux"; + assert withHostAndBuild._module.args.pkgs.stdenv.buildPlatform.system == "aarch64-darwin"; + assert builtins.trace (lib.head (getErrors ambiguous)) + getErrors ambiguous == + ['' + Your system configures nixpkgs with the platform parameters: + nixpkgs.hostPlatform, with values defined in: + - repeat.nix + - ambiguous.nix + nixpkgs.buildPlatform, with values defined in: + - ambiguous.nix + + However, it also defines the legacy options: + nixpkgs.system, with values defined in: + - ambiguous.nix + nixpkgs.localSystem, with values defined in: + - ambiguous.nix + nixpkgs.crossSystem, with values defined in: + - ambiguous.nix + + For a future proof system configuration, we recommend to remove + the legacy definitions. + '']; + pkgs.emptyFile; }