feat(monitoring): support cgroup exporting of metrics

This needs an update in our node_exporter dashboard but nothing too
hard.

Signed-off-by: Ryan Lahfa <ryan@dgnum.eu>

modules/nixos/dgn-node-monitoring.nix

@@ -1,4 +1,10 @@
-{ config, lib, ... }:
+{
+  pkgs,
+  sources,
+  config,
+  lib,
+  ...
+}:
 let
   inherit (lib)
     mkEnableOption
@@ -24,6 +30,10 @@ in
     };
   };
 
+  imports = [
+    "${sources.cgroup-exporter}/nix/module.nix"
+  ];
+
   config = mkIf cfg.enable {
     services.prometheus = {
       exporters = {
@@ -36,6 +46,10 @@ in
           inherit (cfg) port;
           listenAddress = "0.0.0.0";
         };
+        cgroup = {
+          enable = true;
+          package = pkgs.callPackage "${sources.cgroup-exporter}/nix/package.nix" { };
+        };
       };
     };
     networking.firewall.interfaces.wt0.allowedTCPPorts = [ cfg.port ];

npins/sources.json

@@ -38,6 +38,18 @@
       "url": null,
       "hash": "09z5l5yh4zm0mf9hb3xc18gjk2dgv3l1icywrsxax00y1i1zlvna"
     },
+    "cgroup-exporter": {
+      "type": "Git",
+      "repository": {
+        "type": "GitHub",
+        "owner": "arianvp",
+        "repo": "cgroup-exporter"
+      },
+      "branch": "main",
+      "revision": "816bfe1bc881ae43cf392949c47d8516a48fceeb",
+      "url": "https://github.com/arianvp/cgroup-exporter/archive/816bfe1bc881ae43cf392949c47d8516a48fceeb.tar.gz",
+      "hash": "1axg15ixja9vk78kz6mlixcd16j6h1agb52jvlwhnj56jw4ifvq8"
+    },
     "colmena": {
       "type": "Git",
       "repository": {