nixos/clatd: add enableNetworkManagerIntegration option

nixos/modules/services/networking/clatd.nix

@@ -13,6 +13,11 @@ in
 
       package = lib.mkPackageOption pkgs "clatd" { };
 
+      enableNetworkManagerIntegration = lib.mkEnableOption "NetworkManager integration" // {
+        default = config.networking.networkmanager.enable;
+        defaultText = "config.networking.networkmanager.enable";
+      };
+
       settings = lib.mkOption {
         type = lib.types.submodule ({ name, ... }: {
           freeformType = settingsFormat.type;
@@ -75,5 +80,17 @@ in
         ];
       };
     };
+
+    networking.networkmanager.dispatcherScripts = cfg.enableNetworkManagerIntegration [
+      {
+        type = "basic";
+        # https://github.com/toreanderson/clatd/blob/master/scripts/clatd.networkmanager
+        source = pkgs.writeShellScript "restart-clatd" ''
+          [ "$DEVICE_IFACE" = "clat" ] && exit 0
+          [ "$2" != "up" ] && [ "$2" != "down" ] && exit 0
+          ${pkgs.systemd}/bin/systemctl restart clatd.service
+        '';
+      }
+    ];
   };
 }