Added firewall rule for node exporters

config/headless.nix

@@ -14,6 +14,8 @@
       enable = true;
       port = 9002;
       enabledCollectors = [ "systemd" "processes" ];
+      openFirewall = true;
+      firewallFilter = "-s 192.168.100.41 -p tcp -m tcp --dport 9002";
   };
 
   system.stateVersion = "24.05";