Prometheus
Prometheus is an open-source event monitoring and alerting application. It records metrics in a time series database built by pulling (also known as scraping) metrics from different services, with flexible queries and real-time alerting.
Prometheus exporters
Prometheus works by scraping from HTTP endpoints, which are often provided by Prometheus exporters.
node_exporter
Below is an example of prometheus node_exporter with additional collectors enabled. node_exporter is documented in the NixOS manual.
❄︎ /etc/nixos/configuration.nix
{ config, pkgs, ... }:
{
# https://nixos.org/manual/nixos/stable/#module-services-prometheus-exporters
# https://github.com/NixOS/nixpkgs/blob/nixos-24.05/nixos/modules/services/monitoring/prometheus/exporters.nix
services.prometheus.exporters.node = {
enable = true;
port = 9000;
# For the list of available collectors, run, depending on your install:
# - Flake-based: nix run nixpkgs#prometheus-node-exporter -- --help
# - Classic: nix-shell -p prometheus-node-exporter --run "node_exporter --help"
enabledCollectors = [
"ethtool"
"softirqs"
"systemd"
"tcpstat"
"wifi"
];
# You can pass extra options to the exporter using `extraFlags`, e.g.
# to configure collectors or disable those enabled by default.
# Enabling a collector is also possible using "--collector.[name]",
# but is otherwise equivalent to using `enabledCollectors` above.
extraFlags = [ "--collector.ntp.protocol-version=4" "--no-collector.mdadm" ];
};
}
Usage
The Prometheus service daemon can be enabled and configured by further options.
❄︎ /etc/nixos/configuration.nix
{
services.prometheus.enable = true;
}
Another example:
❄︎ /etc/nixos/configuration.nix
{ config, pkgs, ... }:
{
# https://wiki.nixos.org/wiki/Prometheus
# https://nixos.org/manual/nixos/stable/#module-services-prometheus-exporters-configuration
# https://github.com/NixOS/nixpkgs/blob/nixos-24.05/nixos/modules/services/monitoring/prometheus/default.nix
services.prometheus = {
enable = true;
globalConfig.scrape_interval = "10s"; # "1m"
scrapeConfigs = [
{
job_name = "node";
static_configs = [{
targets = [ "localhost:${toString config.services.prometheus.exporters.node.port}" ];
}];
}
];
};
}