nixpkgs/nixos/modules/system/activation/top-level.nix

233 lines
6.9 KiB
Nix

{ config, lib, pkgs, modules, baseModules, ... }:
with lib;
let
# This attribute is responsible for creating boot entries for
# child configuration. They are only (directly) accessible
# when the parent configuration is boot default. For example,
# you can provide an easy way to boot the same configuration
# as you use, but with another kernel
# !!! fix this
cloner = inheritParent: list:
map (childConfig:
(import ../../../lib/eval-config.nix {
inherit baseModules;
modules =
(optionals inheritParent modules)
++ [ ./no-clone.nix ]
++ [ childConfig ];
}).config.system.build.toplevel
) list;
children =
cloner false config.nesting.children
++ cloner true config.nesting.clone;
systemBuilder =
let
kernelPath = "${config.boot.kernelPackages.kernel}/" +
"${config.system.boot.loader.kernelFile}";
in ''
mkdir $out
# Containers don't have their own kernel or initrd. They boot
# directly into stage 2.
${optionalString (!config.boot.isContainer) ''
if [ ! -f ${kernelPath} ]; then
echo "The bootloader cannot find the proper kernel image."
echo "(Expecting ${kernelPath})"
false
fi
ln -s ${kernelPath} $out/kernel
ln -s ${config.system.modulesTree} $out/kernel-modules
echo -n "$kernelParams" > $out/kernel-params
ln -s ${config.system.build.initialRamdisk}/initrd $out/initrd
ln -s ${config.hardware.firmware} $out/firmware
''}
echo "$activationScript" > $out/activate
substituteInPlace $out/activate --subst-var out
chmod u+x $out/activate
unset activationScript
cp ${config.system.build.bootStage2} $out/init
substituteInPlace $out/init --subst-var-by systemConfig $out
ln -s ${config.system.build.etc}/etc $out/etc
ln -s ${config.system.path} $out/sw
ln -s "$systemd" $out/systemd
echo -n "$configurationName" > $out/configuration-name
echo -n "systemd ${toString config.systemd.package.interfaceVersion}" > $out/init-interface-version
echo -n "$nixosVersion" > $out/nixos-version
echo -n "$system" > $out/system
mkdir $out/fine-tune
childCount=0
for i in $children; do
childCount=$(( childCount + 1 ))
ln -s $i $out/fine-tune/child-$childCount
done
mkdir $out/bin
substituteAll ${./switch-to-configuration.pl} $out/bin/switch-to-configuration
chmod +x $out/bin/switch-to-configuration
${config.system.extraSystemBuilderCmds}
'';
# Handle assertions
failed = map (x: x.message) (filter (x: !x.assertion) config.assertions);
showWarnings = res: fold (w: x: builtins.trace "^[[1;31mwarning: ${w}^[[0m" x) res config.warnings;
# Putting it all together. This builds a store path containing
# symlinks to the various parts of the built configuration (the
# kernel, systemd units, init scripts, etc.) as well as a script
# `switch-to-configuration' that activates the configuration and
# makes it bootable.
baseSystem = showWarnings (
if [] == failed then pkgs.stdenv.mkDerivation {
name = "nixos-${config.system.nixosVersion}";
preferLocalBuild = true;
buildCommand = systemBuilder;
inherit (pkgs) utillinux coreutils;
systemd = config.systemd.package;
inherit children;
kernelParams = config.boot.kernelParams;
installBootLoader =
config.system.build.installBootLoader
or "echo 'Warning: do not know how to make this configuration bootable; please enable a boot loader.' 1>&2; true";
activationScript = config.system.activationScripts.script;
nixosVersion = config.system.nixosVersion;
configurationName = config.boot.loader.grub.configurationName;
# Needed by switch-to-configuration.
perl = "${pkgs.perl}/bin/perl -I${pkgs.perlPackages.FileSlurp}/lib/perl5/site_perl";
} else throw "\nFailed assertions:\n${concatStringsSep "\n" (map (x: "- ${x}") failed)}");
# Replace runtime dependencies
system = fold ({ oldDependency, newDependency }: drv:
pkgs.replaceDependency { inherit oldDependency newDependency drv; }
) baseSystem config.system.replaceRuntimeDependencies;
in
{
options = {
system.build = mkOption {
internal = true;
default = {};
description = ''
Attribute set of derivations used to setup the system.
'';
};
nesting.children = mkOption {
default = [];
description = ''
Additional configurations to build.
'';
};
nesting.clone = mkOption {
default = [];
description = ''
Additional configurations to build based on the current
configuration which is has a lower priority.
'';
};
system.boot.loader.id = mkOption {
internal = true;
default = "";
description = ''
Id string of the used bootloader.
'';
};
system.boot.loader.kernelFile = mkOption {
internal = true;
default = pkgs.stdenv.platform.kernelTarget;
type = types.str;
description = ''
Name of the kernel file to be passed to the bootloader.
'';
};
system.copySystemConfiguration = mkOption {
type = types.bool;
default = false;
description = ''
If enabled, copies the NixOS configuration file
<literal>$NIXOS_CONFIG</literal> (usually
<filename>/etc/nixos/configuration.nix</filename>)
to the system store path.
'';
};
system.extraSystemBuilderCmds = mkOption {
type = types.lines;
internal = true;
default = "";
description = ''
This code will be added to the builder creating the system store path.
'';
};
system.replaceRuntimeDependencies = mkOption {
default = [];
example = lib.literalExample "[ ({ original = pkgs.openssl; replacement = pkgs.callPackage /path/to/openssl { ... }; }) ]";
type = types.listOf (types.submodule (
{ options, ... }: {
options.original = mkOption {
type = types.package;
description = "The original package to override.";
};
options.replacement = mkOption {
type = types.package;
description = "The replacement package.";
};
})
);
apply = map ({ original, replacement, ... }: {
oldDependency = original;
newDependency = replacement;
});
description = ''
List of packages to override without doing a full rebuild.
The original derivation and replacement derivation must have the same
name length, and ideally should have close-to-identical directory layout.
'';
};
};
config = {
system.extraSystemBuilderCmds =
optionalString
config.system.copySystemConfiguration
"cp ${maybeEnv "NIXOS_CONFIG" "/etc/nixos/configuration.nix"} $out";
system.build.toplevel = system;
};
}