jungle-backup/m/hut/nix-daemon-exporter.nix
Rodrigo Arias Mallo 1c15e77c83 Add custom nix-daemon exporter
Allows us to see which derivations are being built in realtime. It is a
bit of a hack, but it seems to work. We simply look at the environment
of the child processes of nix-daemon (usually bash) and then look for
the $name variable which should hold the current derivation being
built. Needs root to be able to read the environ file of the different
nix-daemon processes as they are owned by the nixbld* users.

See: https://discourse.nixos.org/t/query-ongoing-builds/23486
Reviewed-by: Aleix Boné <abonerib@bsc.es>
2025-05-29 12:57:07 +02:00

24 lines
598 B
Nix

{ pkgs, config, lib, ... }:
let
script = pkgs.runCommand "nix-daemon-exporter.sh" { }
''
cp ${./nix-daemon-builds.sh} $out;
chmod +x $out
''
;
in
{
systemd.services.nix-daemon-exporter = {
description = "Daemon to export nix-daemon metrics";
path = [ pkgs.procps pkgs.ripgrep ];
wantedBy = [ "default.target" ];
serviceConfig = {
Type = "simple";
ExecStart = "${pkgs.socat}/bin/socat TCP4-LISTEN:9999,fork EXEC:${script}";
# Needed root to read the environment, potentially unsafe
User = "root";
Group = "root";
};
};
}