linux-sysadmin

What problem does it solve?

It prevents and resolves production outages caused by broken OS-level services, misconfigured reverse proxy/TLS/firewall rules, resource exhaustion (disk/RAM/OOM/load/fd), and incident triage on Ubuntu 24.04 stacks (Angie, PM2, PostgreSQL, Redis, Docker).

Core Features & Use Cases

• Reverse proxy, TLS, and certificate ops: Diagnose and fix Angie/Nginx issues like 502/504, SSL expiry, OCSP stapling problems, and ACME/certbot renewal reload gaps.
• Service and OS lifecycle reliability: Handle systemd unit/timer correctness, safe reload workflows, logs via journalctl, and PM2/Docker runtime health.
• Security and traffic safety: Configure UFW + fail2ban baselines, avoid SSH lockouts, and apply hardening guidance for high-stakes changes.
• Incident diagnostics with symptom-indexed fixes: Provide paste-runnable one-liners and stepwise escalation for common high-impact failures (disk full, OOM-killer, conntrack full, DNS resolver down, EMFILE).

Quick Start

Use linux-sysadmin to diagnose and fix my production outage on Ubuntu 24.04 by routing the request to the relevant symptom section, then propose safe verification commands and a rollback plan if changes are required.