Linux Server Fix Guides

Exact copy-paste fix commands for Docker, UFW, Nginx, SSL, cron, and robots.txt issues. Stack-specific — the fix for Ubuntu looks different from the fix for Debian.

Docker Fix Guides

Hardcoded secrets, missing healthchecks, port collisions, UFW bypass, 0.0.0.0 bindings.

UFW Firewall Fix Guides

Docker bypass, default-deny missing, IPv6 mismatch, port exposed after Docker.

nftables Fix Guides

Ubuntu 22 nftables setup, Docker conflict resolution.

Cron Job Fix Guides

Overlapping jobs, silent failure, flock safety, server load spikes, AI agent collision.

SSL Certificate Fix Guides

Expiry monitoring, CDN domain risks, Traefik renewal, Nginx renewal, 200-day warnings.

Nginx Fix Guides

502 Bad Gateway, upstream timeout, missing SSL redirect.

robots.txt Fix Guides

Accidental crawl blocks, missing AI bot directives, sitemap reference, crawl-delay.

Reverse Proxy Fix Guides

Traefik v2→v3 migration, dangling routes, CORS double headers, missing rate limits.