nixpkgs/nixos/modules/services/networking/ntpd.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

96 lines
1.8 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
inherit (pkgs) ntp;
stateDir = "/var/lib/ntp";
ntpUser = "ntp";
configFile = pkgs.writeText "ntp.conf" ''
# Keep the drift file in ${stateDir}/ntp.drift. However, since we
# chroot to ${stateDir}, we have to specify it as /ntp.drift.
driftfile /ntp.drift
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
${toString (map (server: "server " + server + " iburst\n") config.services.ntp.servers)}
'';
ntpFlags = "-c ${configFile} -u ${ntpUser}:nogroup -i ${stateDir}";
in
{
###### interface
options = {
services.ntp = {
enable = mkOption {
default = !config.boot.isContainer;
description = ''
Whether to synchronise your machine's time using the NTP
protocol.
'';
};
servers = mkOption {
default = [
"0.pool.ntp.org"
"1.pool.ntp.org"
"2.pool.ntp.org"
];
description = ''
The set of NTP servers from which to synchronise.
'';
};
};
};
###### implementation
config = mkIf config.services.ntp.enable {
# Make tools such as ntpq available in the system path
environment.systemPackages = [ pkgs.ntp ];
users.extraUsers = singleton
{ name = ntpUser;
uid = config.ids.uids.ntp;
description = "NTP daemon user";
home = stateDir;
};
jobs.ntpd =
{ description = "NTP Daemon";
wantedBy = [ "ip-up.target" ];
partOf = [ "ip-up.target" ];
path = [ ntp ];
preStart =
''
mkdir -m 0755 -p ${stateDir}
chown ${ntpUser} ${stateDir}
'';
exec = "ntpd -g -n ${ntpFlags}";
};
};
}