nixpkgs-suyu/modules/system/activation/activation-script.nix
Eelco Dolstra 3495a773f9 * Improved Upstart job handling in switch-to-configuration. It no
longer compares the current configuration to the previous
  configuration, but instead compares the current Upstart state to the
  intended state.  Thus, if the switch script is interrupted, running
  nixos-rebuild again will resume starting/stopping Upstart jobs where
  the previous run left off.

  We determine if an Upstart job has changed by having the pre-start
  script of each Upstart job put a symlink to its .conf file in
  /var/run/upstart-jobs.  So if this symlink differs from the target
  of /etc/init/<job>.conf, then the job has changed.  This also
  prevents multiple restarts of dependent jobs.  E.g., if job B has
  "start on started A" and "stop on stopping A", then restarting A
  will cause B to be restarted, so B shouldn't B restarted a second
  time.

  We only start jobs that are not running if 1) they're tasks that
  have been previously run (like mountall); or 2) they're jobs that
  have a "start on" condition.  This seems a reasonable heuristic.

svn path=/nixos/trunk/; revision=33222
2012-03-18 01:53:35 +00:00

146 lines
3.6 KiB
Nix

# generate the script used to activate the configuration.
{ config, pkgs, ... }:
with pkgs.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 = ''
Activate the new configuration (i.e., update /etc, make accounts,
and so on).
'';
merge = mergeTypedOption "script" builtins.isAttrs (fold mergeAttrs {});
apply = set: {
script =
''
#! ${pkgs.stdenv.shell}
systemConfig=@out@
export PATH=/empty
for i in ${toString path}; do
PATH=$PATH:$i/bin:$i/sbin;
done
${
let
set' = mapAttrs (n: v: if builtins.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 $systemConfig = /system
# (which is a symlink to the store), /var/run/current-system is still
# used as a garbage collection root.
ln -sfn "$(readlink -f "$systemConfig")" /var/run/current-system
# Prevent the current configuration from being garbage-collected.
ln -sfn /var/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
# Directory holding symlinks to currently running Upstart
# jobs. Used to determine which jobs need to be restarted
# when switching to a new configuration.
mkdir -m 0700 -p /var/run/upstart-jobs
mkdir -m 0755 -p /var/log
mkdir -m 0755 -p /var/log/upstart
touch /var/log/wtmp # must exist
chmod 644 /var/log/wtmp
touch /var/log/lastlog
chmod 644 /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
'';
};
}