+{ lib, config, pkgs, ... }:
+with lib;
+let
+ cfg = config.services.filesWatcher;
+in
+{
+ options = {
+ services.filesWatcher = with types; mkOption {
+ default = {};
+ description = ''
+ Files to watch and trigger service reload or restart of service
+ when changed.
+ '';
+ type = attrsOf (submodule {
+ options = {
+ restart = mkEnableOption "Restart service rather than reloading it";
+ paths = mkOption {
+ type = listOf str;
+ description = ''
+ Paths to watch that should trigger a reload of the
+ service
+ '';
+ };
+ waitTime = mkOption {
+ type = int;
+ default = 5;
+ description = ''
+ Time to wait before reloading/restarting the service.
+ Set 0 to not wait.
+ '';
+ };
+ };
+ });
+ };
+ };
+
+ config.systemd.services = attrsets.mapAttrs' (name: icfg: attrsets.nameValuePair
+ "${name}Watcher" {
+ description = "${name} reloader";
+ after = [ "network.target" ];
+ script = let
+ action = if icfg.restart then "restart" else "reload";
+ in ''
+ # Service may be stopped during file modification (e.g. activationScripts)
+ if ${pkgs.systemd}/bin/systemctl --quiet is-active ${name}.service; then
+ ${pkgs.coreutils}/bin/sleep ${toString icfg.waitTime}
+ ${pkgs.systemd}/bin/systemctl ${action} ${name}.service
+ fi
+ '';
+ serviceConfig = {
+ Type = "oneshot";
+ };
+ }
+ ) cfg;
+ config.systemd.paths = attrsets.mapAttrs' (name: icfg: attrsets.nameValuePair
+ "${name}Watcher" {
+ wantedBy = [ "multi-user.target" ];
+ pathConfig.PathChanged = icfg.paths;
+ }
+ ) cfg;
+}