infra/services/monitoring/exporters/postgres.nix

{
  config,
  lib,
  ...
}:
let
  cfg = config.bagel.monitoring.exporters.postgres;
  inherit (lib) mkEnableOption mkIf;
in
{
  options.bagel.monitoring.exporters.postgres.enable = (mkEnableOption "Postgres exporter") // { default = config.services.postgresql.enable; };

  config = mkIf cfg.enable {
    services.prometheus.exporters.postgres = {
      enable = true;
      port = 9104;
      runAsLocalSuperUser = true;
      extraFlags = [
        "--collector.long_running_transactions"
        "--collector.stat_activity_autovacuum"
        "--collector.stat_statements"
      ];
    };

    services.postgresql.settings.shared_preload_libraries = "pg_stat_statements";
    systemd.services.postgresql.postStart = lib.mkAfter ''
      ${config.services.postgresql.package}/bin/psql -U postgres -c "CREATE EXTENSION IF NOT EXISTS pg_stat_statements;";
    '';

    bagel.monitoring.grafana-agent.exporters.postgres.port = 9104;
  };
}