ALERT K8SSchedulerDown
  IF absent(up{job="kube-scheduler"} == 1)
  FOR 5m
  LABELS {
    severity = "critical",
  }
  ANNOTATIONS {
    summary = "Scheduler is down",
    description = "There is no running K8S scheduler. New pods are not being assigned to nodes.",
    runbook = "https://coreos.com/tectonic/docs/latest/troubleshooting/controller-recovery.html#recovering-a-scheduler",
  }