mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-11-23 07:23:20 +00:00
78d8e2ca11
Running systemd-timesyncd with an empty list of timeservers to sync from
does not work.
In case an empty list is configured here, systemd will fall back to its
compiled-in defaults, which NixOS sets to `{0..4}.nixos.pool.ntp.org`,
as per https://github.com/systemd/systemd/blob/main/docs/DISTRO_PORTING.md#ntp-pool
This has caused some confusion. Explicitly document this, and describe
how to disable timesyncd.
96 lines
3.9 KiB
Nix
96 lines
3.9 KiB
Nix
{ config, lib, ... }:
|
|
|
|
with lib;
|
|
|
|
{
|
|
|
|
options = {
|
|
|
|
services.timesyncd = {
|
|
enable = mkOption {
|
|
default = !config.boot.isContainer;
|
|
defaultText = literalExpression "!config.boot.isContainer";
|
|
type = types.bool;
|
|
description = lib.mdDoc ''
|
|
Enables the systemd NTP client daemon.
|
|
'';
|
|
};
|
|
servers = mkOption {
|
|
default = config.networking.timeServers;
|
|
defaultText = literalExpression "config.networking.timeServers";
|
|
type = types.listOf types.str;
|
|
description = lib.mdDoc ''
|
|
The set of NTP servers from which to synchronise.
|
|
Note if this is set to an empty list, the defaults systemd itself is
|
|
compiled with ({0..4}.nixos.pool.ntp.org) apply,
|
|
In case you want to disable timesyncd altogether, use the `enable` option.
|
|
'';
|
|
};
|
|
extraConfig = mkOption {
|
|
default = "";
|
|
type = types.lines;
|
|
example = ''
|
|
PollIntervalMaxSec=180
|
|
'';
|
|
description = lib.mdDoc ''
|
|
Extra config options for systemd-timesyncd. See
|
|
[
|
|
timesyncd.conf(5)](https://www.freedesktop.org/software/systemd/man/timesyncd.conf.html) for available options.
|
|
'';
|
|
};
|
|
};
|
|
};
|
|
|
|
config = mkIf config.services.timesyncd.enable {
|
|
|
|
systemd.additionalUpstreamSystemUnits = [ "systemd-timesyncd.service" ];
|
|
|
|
systemd.services.systemd-timesyncd = {
|
|
wantedBy = [ "sysinit.target" ];
|
|
aliases = [ "dbus-org.freedesktop.timesync1.service" ];
|
|
restartTriggers = [ config.environment.etc."systemd/timesyncd.conf".source ];
|
|
# systemd-timesyncd disables DNSSEC validation in the nss-resolve module by setting SYSTEMD_NSS_RESOLVE_VALIDATE to 0 in the unit file.
|
|
# This is required in order to solve the chicken-and-egg problem when DNSSEC validation needs the correct time to work, but to set the
|
|
# correct time, we need to connect to an NTP server, which usually requires resolving its hostname.
|
|
# In order for nss-resolve to be able to read this environment variable we patch systemd-timesyncd to disable NSCD and use NSS modules directly.
|
|
# This means that systemd-timesyncd needs to have NSS modules path in LD_LIBRARY_PATH. When systemd-resolved is disabled we still need to set
|
|
# NSS module path so that systemd-timesyncd keeps using other NSS modules that are configured in the system.
|
|
environment.LD_LIBRARY_PATH = config.system.nssModules.path;
|
|
|
|
preStart = (
|
|
# Ensure that we have some stored time to prevent
|
|
# systemd-timesyncd to resort back to the fallback time. If
|
|
# the file doesn't exist we assume that our current system
|
|
# clock is good enough to provide an initial value.
|
|
''
|
|
if ! [ -f /var/lib/systemd/timesync/clock ]; then
|
|
test -d /var/lib/systemd/timesync || mkdir -p /var/lib/systemd/timesync
|
|
touch /var/lib/systemd/timesync/clock
|
|
fi
|
|
'' +
|
|
# workaround an issue of systemd-timesyncd not starting due to upstream systemd reverting their dynamic users changes
|
|
# - https://github.com/NixOS/nixpkgs/pull/61321#issuecomment-492423742
|
|
# - https://github.com/systemd/systemd/issues/12131
|
|
(lib.optionalString (versionOlder config.system.stateVersion "19.09") ''
|
|
if [ -L /var/lib/systemd/timesync ]; then
|
|
rm /var/lib/systemd/timesync
|
|
mv /var/lib/private/systemd/timesync /var/lib/systemd/timesync
|
|
fi
|
|
'')
|
|
);
|
|
};
|
|
|
|
environment.etc."systemd/timesyncd.conf".text = ''
|
|
[Time]
|
|
NTP=${concatStringsSep " " config.services.timesyncd.servers}
|
|
${config.services.timesyncd.extraConfig}
|
|
'';
|
|
|
|
users.users.systemd-timesync = {
|
|
uid = config.ids.uids.systemd-timesync;
|
|
group = "systemd-timesync";
|
|
};
|
|
users.groups.systemd-timesync.gid = config.ids.gids.systemd-timesync;
|
|
};
|
|
}
|