nixpkgs/nixos/modules/system/activation/top-level.nix
Eelco Dolstra 29027fd1e1 Rewrite ‘with pkgs.lib’ -> ‘with lib’
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
2014-04-14 16:26:48 +02:00

195 lines
5.3 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
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
${config.system.extraSystemBuilderCmds}
'';
# Putting it all together. This builds a store path containing
# symlinks to the various parts of the built configuration (the
# kernel, systemd units, init scripts, etc.) as well as a script
# `switch-to-configuration' that activates the configuration and
# makes it bootable.
system = pkgs.stdenv.mkDerivation {
name = "nixos-${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";
};
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.
'';
};
};
config = {
system.extraSystemBuilderCmds =
optionalString
config.system.copySystemConfiguration
"cp ${maybeEnv "NIXOS_CONFIG" "/etc/nixos/configuration.nix"} $out";
system.build.toplevel = system;
};
}