nixpkgs/nixos/modules/system/activation/activation-script.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

151 lines
3.9 KiB
Nix

# generate the script used to activate the configuration.
{ config, lib, pkgs, ... }:
with lib;
let
addAttributeName = mapAttrs (a: v: v // {
text = ''
#### Activation script snippet ${a}:
${v.text}
'';
});
path =
[ pkgs.coreutils pkgs.gnugrep pkgs.findutils
pkgs.glibc # needed for getent
pkgs.shadow
pkgs.nettools # needed for hostname
];
in
{
###### interface
options = {
system.activationScripts = mkOption {
default = {};
example = {
stdio = {
text = ''
# Needed by some programs.
ln -sfn /proc/self/fd /dev/fd
ln -sfn /proc/self/fd/0 /dev/stdin
ln -sfn /proc/self/fd/1 /dev/stdout
ln -sfn /proc/self/fd/2 /dev/stderr
'';
deps = [];
};
};
description = ''
A set of shell script fragments that are executed when a NixOS
system configuration is activated. Examples are updating
/etc, creating accounts, and so on. Since these are executed
every time you boot the system or run
<command>nixos-rebuild</command>, it's important that they are
idempotent and fast.
'';
type = types.attrsOf types.unspecified; # FIXME
apply = set: {
script =
''
#! ${pkgs.stdenv.shell}
systemConfig=@out@
export PATH=/empty
for i in ${toString path}; do
PATH=$PATH:$i/bin:$i/sbin
done
# Ensure a consistent umask.
umask 0022
${
let
set' = mapAttrs (n: v: if isString v then noDepEntry v else v) set;
withHeadlines = addAttributeName set';
in textClosureMap id (withHeadlines) (attrNames withHeadlines)
}
# Make this configuration the current configuration.
# The readlink is there to ensure that when $systemConfig = /system
# (which is a symlink to the store), /run/current-system is still
# used as a garbage collection root.
ln -sfn "$(readlink -f "$systemConfig")" /run/current-system
# Prevent the current configuration from being garbage-collected.
ln -sfn /run/current-system /nix/var/nix/gcroots/current-system
'';
};
};
};
###### implementation
config = {
system.activationScripts.stdio =
''
# Needed by some programs.
ln -sfn /proc/self/fd /dev/fd
ln -sfn /proc/self/fd/0 /dev/stdin
ln -sfn /proc/self/fd/1 /dev/stdout
ln -sfn /proc/self/fd/2 /dev/stderr
'';
system.activationScripts.var =
''
# Various log/runtime directories.
touch /var/run/utmp # must exist
chgrp ${toString config.ids.gids.utmp} /var/run/utmp
chmod 664 /var/run/utmp
mkdir -m 0755 -p /var/run/nix/current-load # for distributed builds
mkdir -m 0700 -p /var/run/nix/remote-stores
mkdir -m 0755 -p /var/log
touch /var/log/wtmp /var/log/lastlog # must exist
chmod 644 /var/log/wtmp /var/log/lastlog
mkdir -m 1777 -p /var/tmp
# Empty, read-only home directory of many system accounts.
mkdir -m 0555 -p /var/empty
'';
system.activationScripts.media =
''
mkdir -m 0755 -p /media
'';
system.activationScripts.usrbinenv =
''
mkdir -m 0755 -p /usr/bin
ln -sfn ${pkgs.coreutils}/bin/env /usr/bin/.env.tmp
mv /usr/bin/.env.tmp /usr/bin/env # atomically replace /usr/bin/env
'';
system.activationScripts.tmpfs =
''
${pkgs.utillinux}/bin/mount -o "remount,size=${config.boot.devSize}" none /dev
${pkgs.utillinux}/bin/mount -o "remount,size=${config.boot.devShmSize}" none /dev/shm
${pkgs.utillinux}/bin/mount -o "remount,size=${config.boot.runSize}" none /run
'';
};
}