Converts Prometheus Alertmanager webhook to Discord webhook.
Put your Discord webhook URL in the environment variable WEBHOOK.
Rule example:
alert: InstanceDown
expr: up == 0
for: 5m
labels:
severity: critical
annotations:
summary: "Instance {{$labels.instance}} down"
description: "{{$labels.instance}} of job {{$labels.job}} has been down for more than 5 minutes."