Add ngrok service

src/nix/eval-service.nix

@@ -17,6 +17,7 @@ let
     ./modules/service/image.nix
     ./modules/service/nixos.nix
     ./modules/service/nixos-init.nix
+    ./modules/service/ngrok.nix
   ];
 
   argsModule = {

src/nix/modules/service/ngrok.nix

@@ -0,0 +1,32 @@
+{ pkgs, lib, config, ... }:
+
+let
+  inherit (lib) types;
+
+  ngrokConfig = pkgs.writeText "ngrok-tunnels.yml" (builtins.toJSON config.ngrok.config);
+
+in
+{
+  options.ngrok = {
+    enable = lib.mkOption {
+      description = "Turn on ngrok service";
+      type = types.bool;
+      default = false;
+    };
+    config = lib.mkOption {
+      type = types.attrs;
+      description = "ngrok.conf configuration";
+    };
+    userConfigFile = lib.mkOption {
+      type = types.path;
+      default = ~/.ngrok2/ngrok.yml;
+      description = "path to ngrok.conf user configuration";
+    };
+  };
+
+  config = lib.mkIf (config.ngrok.enable) {
+    service.command = [ "${pkgs.ngrok}/bin/ngrok" "start" "--all" "--config" "${ngrokConfig}" "--config" "${config.ngrok.userConfigFile}" ];
+    service.ports = [ "4040:4040" ];
+    ngrok.config.web_addr = "0.0.0.0:4040";
+  };
+}