How we tunnel a public URL into an untrusted sandboxhttps://www.reddit.com/r/programming/comments/1w0x12x/how_we_tunnel_a_public_url_into_an_untrusted
Have you ever thought about how a sandbox tunnels a public URL out to the world when one end of the tunnel is untrusted code owned by the user? Take an example: a localhost:3000 app running in a sandbox inside a VM. The user wants a public link for it. It looks like a reverse proxy. It isn't, because the app behind the link is untrusted code. It feels easy, but for security it's full of hiccups. The naive version, and the holes it leaves. If there's just a public URL, anyone can hit it, and if the user doesn't want it shown to the world, that's not acceptable. If we put a secret token in the…