nixos/waybar: init module

nixos/modules/module-list.nix

@@ -136,6 +136,7 @@
   ./programs/vim.nix
   ./programs/wavemon.nix
   ./programs/way-cooler.nix
+  ./programs/waybar.nix
   ./programs/wireshark.nix
   ./programs/xfs_quota.nix
   ./programs/xonsh.nix

nixos/modules/programs/waybar.nix

@@ -0,0 +1,20 @@
+{ lib, pkgs, config, ... }:
+
+with lib;
+
+{
+  options.programs.waybar = {
+    enable = mkEnableOption "waybar";
+  };
+
+  config = mkIf config.programs.waybar.enable {
+    systemd.user.services.waybar = {
+      description = "Waybar as systemd service";
+      wantedBy = [ "graphical-session.target" ];
+      partOf = [ "graphical-session.target" ];
+      script = "${pkgs.waybar}/bin/waybar";
+    };
+  };
+
+  meta.maintainers = [ maintainers.FlorianFranzen ];
+}