Monitoring our monitoring: how we validate our Prometheus alert rules

Cloudflare uses Prometheus as their core monitoring system since 2017. They've developed an open-source tool called pint to improve the reliability of their alerting rules in Prometheus. Pint is a linter for Prometheus rules that can be run against live Prometheus servers, integrated into CI pipelines, or deployed as a sidecar to all Prometheus servers. It helps detect missing metrics, typos, and other potential problems with Prometheus queries. The tool also allows setting policies for alerting rules, such as requiring annotations and priorities. Pint is useful in ensuring that Prometheus alerting rules always work correctly and notify the team of any incident.