Scope
This skill covers the software layer — what runs inside a machine.
For infrastructure (provisioning VMs, SSH hardening, firewalls, backups), use the vps skill.
When to Use
- Configuring nginx, Caddy, or Apache
- Deploying Node.js, Python, Go, or other apps
- Docker and Docker Compose setups
- SSL/TLS certificates with Let's Encrypt
- Reverse proxy and load balancing
- Process management (pm2, systemd services)
- Troubleshooting port conflicts, CORS, connection errors
- Self-hosting (Plex, Nextcloud, game servers)
- Local development servers (Vite, webpack-dev-server)
Common Pitfalls
- Port already in use — Check with
lsof -i :PORT or ss -tlnp | grep PORT, kill stale processes - CORS in development — Proxy through your dev server or configure backend headers, don't disable in production
- SSL certificate issues — Certbot needs port 80/443 open, use
--standalone or --webroot mode appropriately - nginx config not loading — Always run
nginx -t before systemctl reload nginx - Docker container can't reach host — Use
host.docker.internal (Docker Desktop) or 172.17.0.1 (Linux) - Process dies after SSH disconnect — Use systemd, pm2, or run inside tmux/screen
- Wrong permissions on mounted volumes — Match container user UID with host file ownership
Patterns by Use Case
| Use Case | Recommended Stack |
|---|
| ---------- | ------------------- |
| Static site | Caddy (auto-SSL, zero config) |
| Node.js app | PM2 + nginx reverse proxy |
| Python (Django/FastAPI) | Gunicorn + nginx |
| Multiple services | Docker Compose + Traefik |
| Game server | Dedicated container + port mapping |
For framework-specific configs, see configs.md.
For Docker Compose patterns, see docker.md.
Debugging Checklist
- Is the process running?
systemctl status or docker ps - Is it listening?
ss -tlnp | grep PORT - Can you reach it locally?
curl localhost:PORT - Firewall blocking? Check
ufw status or cloud security groups - Reverse proxy misconfigured? Check nginx logs:
/var/log/nginx/error.log - DNS pointing correctly?
dig domain.com or nslookup