formula-prometheus/prometheus/meta/prometheus.yml

{% raw %}
server:
  alert:
    PrometheusTargetDown:
      if: 'up != 1'
      labels:
        severity: critical
        service: prometheus
      annotations:
        summary: 'Prometheus endpoint {{ $labels.instance }} is down'
        description: 'Prometheus endpoint {{ $labels.instance }} is down for job {{ $labels.job }}'
{% endraw %}