Incident Runbooks

Step-by-step playbooks for when things go sideways. Interactive checklists with copy-paste commands.

SSL Certificate Expired — Emergency Renewal Checklist

Renew an expired or expiring SSL/TLS certificate. Covers Let's Encrypt/certbot renewal, manual certificate replacement, web server reload, and auto-renewal setup.

10 min7 steps

ssltlscertificatewebemergency

TLS Handshake Failure — Diagnosis Guide

Diagnose TLS/SSL connection failures. Covers certificate issues, version mismatches, cipher incompatibility, chain problems, SNI, and mTLS failures.

15 min8 steps

tlssslhandshakecertificatenetworkingopenssl

Let's Encrypt Renewal Failed — certbot Troubleshooting

Fix a certbot renewal that's stuck failing. Covers HTTP-01 + DNS-01 challenges, rate limits, webroot + authenticator mismatches, and getting the cert pushed to services that cached the old chain.

20 min7 steps

letsencryptcertbottlscertificaterenewalsecurity

Prometheus Target Down — No Metrics Being Scraped

Fix a target stuck in `DOWN` on Prometheus's /targets page. Covers network reachability, /metrics format, relabeling mistakes, TLS/auth, and scrape timing.

15 min7 steps

prometheusscrapetargetmetricsmonitoringobservability