nixConfig/nixos/roles/prometheusNodeExporter.nix

{config, ...}: {
  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
    # It was compiled along the following steps:
    # 1. Does the current Debian release supports the collector?
    # 2. Is the collector depracated in the latest release?
    # 3. Could you probably use the collected metrics for monitoring or are they useless because they make no sense in our context
    #    (e.g. power adapter inside a VM, use fibre port connection)?
    disabledCollectors = [
      "arp"
      "bcache"
      "btrfs"
      "dmi"
      "fibrechannel"
      "infiniband"
      "nvme"
      "powersupplyclass"
      "rapl"
      "selinux"
      "tapestats"
      "thermal_zone"
      "udp_queues"
      "xfs"
      "zfs"
    ];
    enabledCollectors = [
      "buddyinfo"
      "ksmd"
      "logind"
      "mountstats"
      "processes"
    ];
  };
  networking.firewall.allowedTCPPorts = [9100];
  environment.persistence.${config.impermanence.name}.directories = ["/var/lib/${config.services.prometheus.stateDir}"];
}