add mosquitto

modules/services/mosquitto.nix

@@ -0,0 +1,14 @@
+{ config, lib, ... }:
+let
+  cfg = config.services.mosquitto;
+in
+{
+  options = {
+    services.mosquitto = {
+      openFirewall = lib.mkEnableOption "Open firewall port for Mosquitto";
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    networking.firewall.allowedTCPPorts = map ({ port, ... }: port) cfg.listeners;
+  };
+}