RTSP proxying with Caddy

[kretaceous (Abhijit Hota)]

System info:

OS: Linux Ubuntu 22.04
Kernel: 5.15.0-69-generic
Caddy version: 2b3046de36bad70bd7e48478c99a8a030fb35b98 (27 Mar 23 22:40 UTC)

Problem

I’m using MediaMTX to proxy an RTSP stream via a WebRTC endpoint. The MediaMTX server exposes a WebRTC endpoint on port 8889.

I need to run the MediaMTX server on a VPS which is using Caddy as a reverse proxy and a static server to serve some other files. I want to reverse proxy a certain path to port 8889 but I get application/x-unknown-filetype errors in the frontend.

Current setup

• Caddyfile

  http://instisafe.iitm.ac.in {
  	handle_path /relay/* {
  		@denied not remote_ip forwarded private_ranges
  		abort @denied	
  		reverse_proxy :8889
  	}
  }
  

• Usage in frontend

  <iframe src="https://instisafe.iitm.ac.in/relay/$cameraID"></iframe>
  

Potential causes/solutions

• After a little digging, I found out that this might be happening because Caddy doesn’t support raw TCP traffic. caddy-l4 might be of help.
• Right now, I’m using MediaMTX to convert RTSP WebRTC and expose it to the frontend. I might try with other methods like HLS.

[francislavoie]

@kretaceous

After a little digging, I found out that this might be happening because Caddy doesn’t support raw TCP traffic. caddy-l4 might be of help.

Correct. Vanilla Caddy only does HTTP. If you need TCP proxying, then you need to use caddy-l4 instead.