Add alvr nixos module

modules/nixos/alvr.nix

@@ -0,0 +1,34 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.programs.alvr;
+in {
+  options = {
+    programs.alvr = {
+      enable = mkEnableOption (lib.mdDoc "ALVR");
+
+      package = mkPackageOption pkgs "alvr" {};
+
+      openFirewall = mkOption {
+        type = types.bool;
+        default = false;
+        description = lib.mdDoc ''
+          Open the default ports in the firewall for the ALVR server.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [cfg.package];
+
+    networking.firewall = mkIf cfg.openFirewall {
+      allowedTCPPorts = [9943 9944];
+      allowedUDPPorts = [9943 9944];
+    };
+  };
+}

modules/nixos/default.nix

@@ -2,5 +2,5 @@
 # These should be stuff you would like to share with others, not your personal configurations.
 {
   # List your module files here
-  # my-module = import ./my-module.nix;
+  alvr = import ./alvr.nix;
 }