1 files changed, 89 insertions, 0 deletions
diff --git a/nixos/modules/services/networking/ntp/ntpd-rs.nix b/nixos/modules/services/networking/ntp/ntpd-rs.nix
new file mode 100644
index 0000000000000..a10b570f30bcd
--- /dev/null
+++ b/nixos/modules/services/networking/ntp/ntpd-rs.nix
@@ -0,0 +1,89 @@
+{ lib, config, pkgs, ... }:
+
+let
+  cfg = config.services.ntpd-rs;
+  format = pkgs.formats.toml { };
+  configFile = format.generate "ntpd-rs.toml" cfg.settings;
+in
+{
+  options.services.ntpd-rs = {
+    enable = lib.mkEnableOption "Network Time Service (ntpd-rs)";
+    metrics.enable = lib.mkEnableOption "ntpd-rs Prometheus Metrics Exporter";
+
+    package = lib.mkPackageOption pkgs "ntpd-rs" { };
+
+    useNetworkingTimeServers = lib.mkOption {
+      type = lib.types.bool;
+      default = true;
+      description = lib.mdDoc ''
+        Use source time servers from {var}`networking.timeServers` in config.
+      '';
+    };
+
+    settings = lib.mkOption {
+      type = lib.types.submodule {
+        freeformType = format.type;
+      };
+      default = { };
+      description = lib.mdDoc ''
+        Settings to write to {file}`ntp.toml`
+
+        See <https://docs.ntpd-rs.pendulum-project.org/man/ntp.toml.5>
+        for more information about available options.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = !config.services.timesyncd.enable;
+        message = ''
+          `ntpd-rs` is not compatible with `services.timesyncd`. Please disable one of them.
+        '';
+      }
+    ];
+
+    environment.systemPackages = [ cfg.package ];
+    systemd.packages = [ cfg.package ];
+
+    services.timesyncd.enable = false;
+    systemd.services.systemd-timedated.environment = {
+      SYSTEMD_TIMEDATED_NTP_SERVICES = "ntpd-rs.service";
+    };
+
+    services.ntpd-rs.settings = {
+      observability = {
+        observation-path = lib.mkDefault "/var/run/ntpd-rs/observe";
+      };
+      source = lib.mkIf cfg.useNetworkingTimeServers (map
+        (ts: {
+          mode = "server";
+          address = ts;
+        })
+        config.networking.timeServers);
+    };
+
+    systemd.services.ntpd-rs = {
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        User = "";
+        Group = "";
+        DynamicUser = true;
+        ExecStart = [ "" "${lib.makeBinPath [ cfg.package ]}/ntp-daemon --config=${configFile}" ];
+      };
+    };
+
+    systemd.services.ntp-rs-metrics = lib.mkIf cfg.metrics.enable {
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        User = "";
+        Group = "";
+        DynamicUser = true;
+        ExecStart = [ "" "${lib.makeBinPath [ cfg.package ]}/bin/ntp-metrics-exporter --config=${configFile}" ];
+      };
+    };
+  };
+
+  meta.maintainers = with lib.maintainers; [ fpletz ];
+}