From 1de0d328607e3323ea6f7619c31331c28a3b69b3 Mon Sep 17 00:00:00 2001
From: Gonne Kretschmer <gonne.kretschmer@stud.tu-darmstadt.de>
Date: Fri, 27 Oct 2023 16:01:07 +0200
Subject: [PATCH] Prometheus Node Exporter metrics configured.

---
 nixos/roles/default.nix                |  8 +-----
 nixos/roles/prometheusNodeExporter.nix | 36 ++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 7 deletions(-)
 create mode 100644 nixos/roles/prometheusNodeExporter.nix

diff --git a/nixos/roles/default.nix b/nixos/roles/default.nix
index 3752a32..bc94eff 100644
--- a/nixos/roles/default.nix
+++ b/nixos/roles/default.nix
@@ -3,6 +3,7 @@
 imports = [
   ./admins.nix
   ./nix_keys.nix
+  ./prometheusNodeExporter.nix
   (modulesPath + "/virtualisation/xen-domU.nix")
   ../modules/impermanence.nix
   ];
@@ -55,12 +56,5 @@ services = {
       PasswordAuthentication = false;
     };
   };
-  
-  prometheus.exporters.node = {
-    enable = true;
-    port = 9100;
   };
-};
-# Prometheus Monitoring
-networking.firewall.allowedTCPPorts = [ 9100 ];
 }
diff --git a/nixos/roles/prometheusNodeExporter.nix b/nixos/roles/prometheusNodeExporter.nix
new file mode 100644
index 0000000..e717411
--- /dev/null
+++ b/nixos/roles/prometheusNodeExporter.nix
@@ -0,0 +1,36 @@
+{
+  imports = [ ];
+  services.prometheus.exporters.node = {
+    enable = true;
+    port = 9100;
+  # Aligned with https://git.rwth-aachen.de/fsdmath/server/prometheus/-/blob/main/node_exporter/etc/default/prometheus-node-exporter
+  # Original reasons are for these lists are unknown, but along the lines
+  # “This looks useless for VMs, but that seems nice.”
+    disabledCollectors = [
+      "arp"
+      "bcache"
+      "btrfs"
+      "dmi"
+      "fibrechannel"
+      "infiniband"
+      "nfs"
+      "nvme"
+      "powersupplyclass"
+      "rapl"
+      "selinux"
+      "tapestats"
+      "thermal_zone"
+      "udp_queues"
+      "xfs"
+      "zfs"
+    ];
+    enabledCollectors = [
+      "buddyinfo"
+      "ksmd"
+      "logind"
+      "mountstats"
+      "processes"
+    ];
+  };
+  networking.firewall.allowedTCPPorts = [ 9100 ];
+}