nixos/katriawm: add module

nixos/modules/services/x11/window-managers/katriawm.nix

@@ -0,0 +1,27 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) mdDoc mkEnableOption mkIf mkPackageOption singleton;
+  cfg = config.services.xserver.windowManager.katriawm;
+in
+{
+  ###### interface
+  options = {
+    services.xserver.windowManager.katriawm = {
+      enable = mkEnableOption (mdDoc "katriawm");
+      package = mkPackageOption pkgs "katriawm" {};
+    };
+  };
+
+  ###### implementation
+  config = mkIf cfg.enable {
+    services.xserver.windowManager.session = singleton {
+      name = "katriawm";
+      start = ''
+        ${cfg.package}/bin/katriawm &
+        waitPID=$!
+      '';
+    };
+    environment.systemPackages = [ cfg.package ];
+  };
+}