nixpkgs/nixos/modules/system/boot/systemd.nix
Shea Levy ca7805be94 systemd: Enable specifying extra config files for a unit
This will allow overriding package-provided units, or overriding only a
specific instance of a unit template.

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-01-18 11:10:39 -05:00

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{ config, pkgs, utils, ... }:
with pkgs.lib;
with utils;
with import ./systemd-unit-options.nix { inherit config pkgs; };
let
cfg = config.systemd;
systemd = cfg.package;
makeUnit = name: unit:
pkgs.runCommand "unit" { preferLocalBuild = true; inherit (unit) text; }
((if !unit.enable then ''
mkdir -p $out
ln -s /dev/null $out/${name}
'' else if unit.linkTarget != null then ''
mkdir -p $out
ln -s ${unit.linkTarget} $out/${name}
'' else if unit.text != null then ''
mkdir -p $out
echo -n "$text" > $out/${name}
'' else "") + optionalString (unit.extraConfig != {}) ''
mkdir -p $out/${name}.d
${concatStringsSep "\n" (mapAttrsToList (n: v: "echo -n \"${v}\" > $out/${name}.d/${n}") unit.extraConfig)}
'');
upstreamUnits =
[ # Targets.
"basic.target"
"sysinit.target"
"sockets.target"
"graphical.target"
"multi-user.target"
"getty.target"
"network.target"
"network-online.target"
"nss-lookup.target"
"nss-user-lookup.target"
"time-sync.target"
#"cryptsetup.target"
"sigpwr.target"
"timers.target"
"paths.target"
# Rescue mode.
"rescue.target"
"rescue.service"
# Udev.
"systemd-udevd-control.socket"
"systemd-udevd-kernel.socket"
"systemd-udevd.service"
"systemd-udev-settle.service"
"systemd-udev-trigger.service"
# Hardware (started by udev when a relevant device is plugged in).
"sound.target"
"bluetooth.target"
"printer.target"
"smartcard.target"
# Login stuff.
"systemd-logind.service"
"autovt@.service"
#"systemd-vconsole-setup.service"
"systemd-user-sessions.service"
"dbus-org.freedesktop.login1.service"
"user@.service"
# Journal.
"systemd-journald.socket"
"systemd-journald.service"
"systemd-journal-flush.service"
"syslog.socket"
# SysV init compatibility.
"systemd-initctl.socket"
"systemd-initctl.service"
# Kernel module loading.
#"systemd-modules-load.service"
# Filesystems.
"systemd-fsck@.service"
"systemd-fsck-root.service"
"systemd-remount-fs.service"
"local-fs.target"
"local-fs-pre.target"
"remote-fs.target"
"remote-fs-pre.target"
"swap.target"
"dev-hugepages.mount"
"dev-mqueue.mount"
"sys-fs-fuse-connections.mount"
"sys-kernel-config.mount"
"sys-kernel-debug.mount"
# Hibernate / suspend.
"hibernate.target"
"suspend.target"
"sleep.target"
"hybrid-sleep.target"
"systemd-hibernate.service"
"systemd-suspend.service"
"systemd-hybrid-sleep.service"
"systemd-shutdownd.socket"
"systemd-shutdownd.service"
# Reboot stuff.
"reboot.target"
"systemd-reboot.service"
"poweroff.target"
"systemd-poweroff.service"
"halt.target"
"systemd-halt.service"
"ctrl-alt-del.target"
"shutdown.target"
"umount.target"
"final.target"
"kexec.target"
"systemd-kexec.service"
# Password entry.
"systemd-ask-password-console.path"
"systemd-ask-password-console.service"
"systemd-ask-password-wall.path"
"systemd-ask-password-wall.service"
]
++ optionals cfg.enableEmergencyMode [
"emergency.target"
"emergency.service"
];
upstreamWants =
[ #"basic.target.wants"
"sysinit.target.wants"
"sockets.target.wants"
"local-fs.target.wants"
"multi-user.target.wants"
"shutdown.target.wants"
"timers.target.wants"
];
makeJobScript = name: text:
let x = pkgs.writeTextFile { name = "unit-script"; executable = true; destination = "/bin/${name}"; inherit text; };
in "${x}/bin/${name}";
unitConfig = { name, config, ... }: {
config = {
unitConfig =
{ Requires = concatStringsSep " " config.requires;
Wants = concatStringsSep " " config.wants;
After = concatStringsSep " " config.after;
Before = concatStringsSep " " config.before;
BindsTo = concatStringsSep " " config.bindsTo;
PartOf = concatStringsSep " " config.partOf;
Conflicts = concatStringsSep " " config.conflicts;
"X-Restart-Triggers" = toString config.restartTriggers;
} // optionalAttrs (config.description != "") {
Description = config.description;
};
};
};
serviceConfig = { name, config, ... }: {
config = mkMerge
[ { # Default path for systemd services. Should be quite minimal.
path =
[ pkgs.coreutils
pkgs.findutils
pkgs.gnugrep
pkgs.gnused
systemd
];
environment.PATH = config.path;
}
(mkIf (config.preStart != "")
{ serviceConfig.ExecStartPre = makeJobScript "${name}-pre-start" ''
#! ${pkgs.stdenv.shell} -e
${config.preStart}
'';
})
(mkIf (config.script != "")
{ serviceConfig.ExecStart = makeJobScript "${name}-start" ''
#! ${pkgs.stdenv.shell} -e
${config.script}
'' + " " + config.scriptArgs;
})
(mkIf (config.postStart != "")
{ serviceConfig.ExecStartPost = makeJobScript "${name}-post-start" ''
#! ${pkgs.stdenv.shell} -e
${config.postStart}
'';
})
(mkIf (config.preStop != "")
{ serviceConfig.ExecStop = makeJobScript "${name}-pre-stop" ''
#! ${pkgs.stdenv.shell} -e
${config.preStop}
'';
})
(mkIf (config.postStop != "")
{ serviceConfig.ExecStopPost = makeJobScript "${name}-post-stop" ''
#! ${pkgs.stdenv.shell} -e
${config.postStop}
'';
})
];
};
mountConfig = { name, config, ... }: {
config = {
mountConfig =
{ What = config.what;
Where = config.where;
} // optionalAttrs (config.type != "") {
Type = config.type;
} // optionalAttrs (config.options != "") {
Options = config.options;
};
};
};
automountConfig = { name, config, ... }: {
config = {
automountConfig =
{ Where = config.where;
};
};
};
toOption = x:
if x == true then "true"
else if x == false then "false"
else toString x;
attrsToSection = as:
concatStrings (concatLists (mapAttrsToList (name: value:
map (x: ''
${name}=${toOption x}
'')
(if isList value then value else [value]))
as));
targetToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
'';
};
serviceToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
[Service]
${let env = cfg.globalEnvironment // def.environment;
in concatMapStrings (n: "Environment=\"${n}=${getAttr n env}\"\n") (attrNames env)}
${optionalString (!def.restartIfChanged) "X-RestartIfChanged=false"}
${optionalString (!def.stopIfChanged) "X-StopIfChanged=false"}
${attrsToSection def.serviceConfig}
'';
};
socketToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
[Socket]
${attrsToSection def.socketConfig}
${concatStringsSep "\n" (map (s: "ListenStream=${s}") def.listenStreams)}
'';
};
timerToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
[Timer]
${attrsToSection def.timerConfig}
'';
};
mountToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
[Mount]
${attrsToSection def.mountConfig}
'';
};
automountToUnit = name: def:
{ inherit (def) wantedBy requiredBy enable;
text =
''
[Unit]
${attrsToSection def.unitConfig}
[Automount]
${attrsToSection def.automountConfig}
'';
};
units = pkgs.runCommand "units" { preferLocalBuild = true; }
''
mkdir -p $out
for i in ${toString upstreamUnits}; do
fn=${systemd}/example/systemd/system/$i
if ! [ -e $fn ]; then echo "missing $fn"; false; fi
if [ -L $fn ]; then
cp -pd $fn $out/
else
ln -s $fn $out/
fi
done
for i in ${toString upstreamWants}; do
fn=${systemd}/example/systemd/system/$i
if ! [ -e $fn ]; then echo "missing $fn"; false; fi
x=$out/$(basename $fn)
mkdir $x
for i in $fn/*; do
y=$x/$(basename $i)
cp -pd $i $y
if ! [ -e $y ]; then rm -v $y; fi
done
done
for i in ${toString (mapAttrsToList (n: v: v.unit) cfg.units)}; do
ln -fs $i/* $out/
done
for i in ${toString cfg.packages}; do
ln -s $i/etc/systemd/system/* $out/
done
${concatStrings (mapAttrsToList (name: unit:
concatMapStrings (name2: ''
mkdir -p $out/'${name2}.wants'
ln -sfn '../${name}' $out/'${name2}.wants'/
'') unit.wantedBy) cfg.units)}
${concatStrings (mapAttrsToList (name: unit:
concatMapStrings (name2: ''
mkdir -p $out/'${name2}.requires'
ln -sfn '../${name}' $out/'${name2}.requires'/
'') unit.requiredBy) cfg.units)}
ln -s ${cfg.defaultUnit} $out/default.target
ln -s rescue.target $out/kbrequest.target
mkdir -p $out/getty.target.wants/
ln -s ../autovt@tty1.service $out/getty.target.wants/
ln -s ../local-fs.target ../remote-fs.target ../network.target ../nss-lookup.target \
../nss-user-lookup.target ../swap.target $out/multi-user.target.wants/
''; # */
in
{
###### interface
options = {
systemd.package = mkOption {
default = pkgs.systemd;
type = types.package;
description = "The systemd package.";
};
systemd.units = mkOption {
description = "Definition of systemd units.";
default = {};
type = types.attrsOf types.optionSet;
options = { name, config, ... }:
{ options = {
text = mkOption {
type = types.nullOr types.str;
default = null;
description = "Text of this systemd unit.";
};
enable = mkOption {
default = true;
type = types.bool;
description = ''
If set to false, this unit will be a symlink to
/dev/null. This is primarily useful to prevent specific
template instances (e.g. <literal>serial-getty@ttyS0</literal>)
from being started.
'';
};
requiredBy = mkOption {
default = [];
type = types.listOf types.string;
description = "Units that require (i.e. depend on and need to go down with) this unit.";
};
wantedBy = mkOption {
default = [];
type = types.listOf types.string;
description = "Units that want (i.e. depend on) this unit.";
};
unit = mkOption {
internal = true;
description = "The generated unit.";
};
linkTarget = mkOption {
default = null;
description = "The file to symlink this target to.";
type = types.nullOr types.path;
};
extraConfig = mkOption {
default = {};
example = { "foo@1.conf" = "X-RestartIfChanged=false"; };
type = types.attrsOf types.lines;
description = ''
Extra files to be appended to the configuration for the unit.
This can be used to override configuration for a unit provided
by systemd or another package, or to override only a single instance
of a template unit.
'';
};
};
config = {
unit = makeUnit name config;
};
};
};
systemd.packages = mkOption {
default = [];
type = types.listOf types.package;
description = "Packages providing systemd units.";
};
systemd.targets = mkOption {
default = {};
type = types.attrsOf types.optionSet;
options = [ unitOptions unitConfig ];
description = "Definition of systemd target units.";
};
systemd.services = mkOption {
default = {};
type = types.attrsOf types.optionSet;
options = [ serviceOptions unitConfig serviceConfig ];
description = "Definition of systemd service units.";
};
systemd.sockets = mkOption {
default = {};
type = types.attrsOf types.optionSet;
options = [ socketOptions unitConfig ];
description = "Definition of systemd socket units.";
};
systemd.timers = mkOption {
default = {};
type = types.attrsOf types.optionSet;
options = [ timerOptions unitConfig ];
description = "Definition of systemd timer units.";
};
systemd.mounts = mkOption {
default = [];
type = types.listOf types.optionSet;
options = [ mountOptions unitConfig mountConfig ];
description = ''
Definition of systemd mount units.
This is a list instead of an attrSet, because systemd mandates the names to be derived from
the 'where' attribute.
'';
};
systemd.automounts = mkOption {
default = [];
type = types.listOf types.optionSet;
options = [ automountOptions unitConfig automountConfig ];
description = ''
Definition of systemd automount units.
This is a list instead of an attrSet, because systemd mandates the names to be derived from
the 'where' attribute.
'';
};
systemd.defaultUnit = mkOption {
default = "multi-user.target";
type = types.str;
description = "Default unit started when the system boots.";
};
systemd.globalEnvironment = mkOption {
type = types.attrs;
default = {};
example = { TZ = "CET"; };
description = ''
Environment variables passed to <emphasis>all</emphasis> systemd units.
'';
};
systemd.extraConfig = mkOption {
default = "";
type = types.lines;
example = "DefaultLimitCORE=infinity";
description = ''
Extra config options for systemd. See man systemd-system.conf for
available options.
'';
};
services.journald.console = mkOption {
default = "";
type = types.str;
description = "If non-empty, write log messages to the specified TTY device.";
};
services.journald.rateLimitInterval = mkOption {
default = "10s";
type = types.str;
description = ''
Configures the rate limiting interval that is applied to all
messages generated on the system. This rate limiting is applied
per-service, so that two services which log do not interfere with
each other's limit. The value may be specified in the following
units: s, min, h, ms, us. To turn off any kind of rate limiting,
set either value to 0.
'';
};
services.journald.rateLimitBurst = mkOption {
default = 100;
type = types.uniq types.int;
description = ''
Configures the rate limiting burst limit (number of messages per
interval) that is applied to all messages generated on the system.
This rate limiting is applied per-service, so that two services
which log do not interfere with each other's limit.
'';
};
services.journald.extraConfig = mkOption {
default = "";
type = types.lines;
example = "Storage=volatile";
description = ''
Extra config options for systemd-journald. See man journald.conf
for available options.
'';
};
services.logind.extraConfig = mkOption {
default = "";
type = types.lines;
example = "HandleLidSwitch=ignore";
description = ''
Extra config options for systemd-logind. See man logind.conf for
available options.
'';
};
systemd.enableEmergencyMode = mkOption {
default = true;
type = types.bool;
description = ''
Whether to enable emergency mode, which is an
<command>sulogin</command> shell started on the console if
mounting a filesystem fails. Since some machines (like EC2
instances) have no console of any kind, emergency mode doesn't
make sense, and it's better to continue with the boot insofar
as possible.
'';
};
};
###### implementation
config = {
system.build.units = units;
environment.systemPackages = [ systemd ];
environment.etc."systemd/system".source = units;
environment.etc."systemd/system.conf".text =
''
[Manager]
${config.systemd.extraConfig}
'';
environment.etc."systemd/journald.conf".text =
''
[Journal]
RateLimitInterval=${config.services.journald.rateLimitInterval}
RateLimitBurst=${toString config.services.journald.rateLimitBurst}
${optionalString (config.services.journald.console != "") ''
ForwardToConsole=yes
TTYPath=${config.services.journald.console}
''}
${config.services.journald.extraConfig}
'';
environment.etc."systemd/logind.conf".text =
''
[Login]
${config.services.logind.extraConfig}
'';
environment.etc."systemd/sleep.conf".text =
''
[Sleep]
'';
system.activationScripts.systemd = stringAfter [ "groups" ]
''
mkdir -m 0755 -p /var/lib/udev
mkdir -p /var/log/journal
chmod 0755 /var/log/journal
# Make all journals readable to users in the wheel and adm
# groups, in addition to those in the systemd-journal group.
# Users can always read their own journals.
${pkgs.acl}/bin/setfacl -nm g:wheel:rx,d:g:wheel:rx,g:adm:rx,d:g:adm:rx /var/log/journal
'';
# Target for charon send-keys to hook into.
systemd.targets.keys =
{ description = "Security Keys";
};
systemd.units =
mapAttrs' (n: v: nameValuePair "${n}.target" (targetToUnit n v)) cfg.targets
// mapAttrs' (n: v: nameValuePair "${n}.service" (serviceToUnit n v)) cfg.services
// mapAttrs' (n: v: nameValuePair "${n}.socket" (socketToUnit n v)) cfg.sockets
// mapAttrs' (n: v: nameValuePair "${n}.timer" (timerToUnit n v)) cfg.timers
// listToAttrs (map
(v: let n = escapeSystemdPath v.where;
in nameValuePair "${n}.mount" (mountToUnit n v)) cfg.mounts)
// listToAttrs (map
(v: let n = escapeSystemdPath v.where;
in nameValuePair "${n}.automount" (automountToUnit n v)) cfg.automounts);
system.requiredKernelConfig = map config.lib.kernelConfig.isEnabled [
"CGROUPS" "AUTOFS4_FS" "DEVTMPFS"
];
environment.shellAliases =
{ start = "systemctl start";
stop = "systemctl stop";
restart = "systemctl restart";
status = "systemctl status";
};
users.extraGroups.systemd-journal.gid = config.ids.gids.systemd-journal;
# Generate timer units for all services that have a startAt value.
systemd.timers =
mapAttrs (name: service:
{ wantedBy = [ "timers.target" ];
timerConfig.OnCalendar = service.startAt;
})
(filterAttrs (name: service: service.startAt != "") cfg.services);
# FIXME: These are borrowed from upstream systemd.
systemd.services."systemd-update-utmp" =
{ description = "Update UTMP about System Reboot/Shutdown";
wantedBy = [ "sysinit.target" ];
after = [ "systemd-remount-fs.service" ];
before = [ "sysinit.target" "shutdown.target" ];
conflicts = [ "shutdown.target" ];
unitConfig = {
DefaultDependencies = false;
RequiresMountsFor = "/var/log";
};
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
ExecStart = "${systemd}/lib/systemd/systemd-update-utmp reboot";
ExecStop = "${systemd}/lib/systemd/systemd-update-utmp shutdown";
};
restartIfChanged = false;
};
systemd.services."systemd-random-seed" =
{ description = "Load/Save Random Seed";
wantedBy = [ "sysinit.target" "multi-user.target" ];
after = [ "systemd-remount-fs.service" ];
before = [ "sysinit.target" "shutdown.target" ];
conflicts = [ "shutdown.target" ];
unitConfig = {
DefaultDependencies = false;
RequiresMountsFor = "/var/lib";
};
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
ExecStart = "${systemd}/lib/systemd/systemd-random-seed load";
ExecStop = "${systemd}/lib/systemd/systemd-random-seed save";
};
};
};
}