the-infra/services/monitoring/exporters/nginx.nix

{
  config,
  lib,
  ...
}:
let
  cfg = config.bagel.monitoring.exporters.nginx;
  inherit (lib) mkEnableOption mkIf;
  logFormat = ''$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" rt=$request_time uct="$upstream_connect_time" uht="$upstream_header_time" urt="$upstream_response_time"'';
in
{
  options.bagel.monitoring.exporters.nginx.enable = (mkEnableOption "Nginx access.log exporter") // { default = config.services.nginx.enable; };

  config = mkIf cfg.enable {
    services.nginx.appendHttpConfig = ''
      log_format ours '${logFormat}';
      access_log /var/log/nginx/access.log ours;
    '';
    
    services.prometheus.exporters.nginxlog = {
      enable = true;
      port = 9103;
      group = "nginx";
      settings.namespaces = [
        {
          name = "nginx";
          format = logFormat;
          source.files = ["/var/log/nginx/access.log"];
        }
      ];
    };

    bagel.monitoring.grafana-agent.exporters.nginxlog.port = 9103;
  };
}