I Set Up Apache Guacamole on a Homelab Mini PC. The Headless Display Gotcha Cost Me an Hour.

I migrated my AI agent stack to a new machine last weekend — an HP EliteDesk 800 G3 mini PC running Ubuntu 24.04. Small form factor, fanless-ish, enough grunt for what I need. The new machine needed proper remote access since it was going into a shelf without a permanently attached monitor. I ended up with Apache Guacamole over Docker, nginx reverse proxy, TOTP 2FA, and three connection types: VNC shared desktop, RDP private XFCE session, and SSH. Here's what actually happened. Why Guacamole? I wanted browser-based remote access — no VPN required, no client to install, works from a phone if needed. Guacamole is the obvious answer for that. It's a clientless remote desktop gateway: you access it via HTTPS in a browser, and it proxies VNC/RDP/SSH connections on the back end. The setup is Docker-native and reasonably well-documented. I used the standard guacamole/guacd + guacamole/guacamole + PostgreSQL stack. The Setup Directory: ~/.openclaw/apps/guacamole/docker-compose.yml Three contai