feat: add prometheus exporter

config/services.nix

@@ -39,4 +39,12 @@ rec {
     port = 8081;
   };
 
+  "metric-exporter" = {
+    port = 9100;
+    collectors = [
+      "systemd"
+      "processes"
+      "thermal_zone"
+    ];
+  };
 }

services/node-exporter.nix

@@ -0,0 +1,12 @@
+{ config, pkgs, lib, ... }:
+let
+  serv = import ../config/services.nix;
+in {
+  services.prometheus.exporters.node = {
+    enable = true;
+    port = serv."metric-exporter".port;
+    enabledCollectors = serv."metric-exporter".collectors;
+  };
+
+  networking.firewall.allowedTCPPorts = [ serv."metric-exporter".port ];
+}