Build a Secure Web Browser Remote Desktop Gateway on a Raspberry Pi

Let’s say I’m in a Starbucks or the airport (or both) and I want to connect to my Windows (or OSX or Linux) machine to do a bit of work. Maybe I don’t want to take my primary computer with me on vacation; maybe I’ll just take a Chromebook. Behind a restrictive firewall all we have is port 80 and port 443 (no VNC or RDP allowed), so let’s make a secure web-based remote desktop gateway with a Raspberry Pi, Docker, and Cloudflare.