{ lib, pkgs, config, ... }: # Standard module arguments
{
  services.vmalert.rules.groups = [
    {
      name = "HostStatusAlerts";
      rules = [
        {
          alert = "HostDown";
          expr = "up == 0";
          for = "2m";
          labels = {
            severity = "critical";
            category = "availability";
          };
          annotations = {
            summary = "Host {{ $labels.instance }} is down";
            description = "Host {{ $labels.instance }} (job: {{ $labels.job }}) has been down for more than 2 minutes.";
          };
        }
      ];
    }
  ];
}