{ lib, pkgs, config, ... }: # Standard module arguments
{
  services.vmalert.rules.groups = [
    {
      name = "RAMUsageAlerts";
      rules = [
        {
          alert = "HighRAMUsage";
          expr = "(1 - node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes) * 100 > 90";
          for = "10m";
          labels = {
            severity = "warning";
            category = "performance";
          };
          annotations = {
            summary = "High RAM usage on {{ $labels.instance }}";
            description = "RAM usage on {{ $labels.instance }} (job: {{ $labels.job }}) has been above 90% for more than 10 minutes. Current value: {{ $value | printf \"%.2f\" }}%.";
          };
        }
      ];
    }
  ];
}