streaming getUserMedia to server
To make this work properly, you need the server to "speak" WebRTC as well. Using websockets won't give you the desired result and will not be as responsive as WebRTC - it won't be real time.
To get WebRTC running on a server, you can use the WebRTC stack at webrtc.org or OpenWebRTC as a starting point, use GStreamer or go for something a bit more complete. Good projects of media server frameworks for WebRTC to start from are Kurento, Jitsi and Janus.
Due to the nature of your question, my suggestion is to start with one of the more complete media server frameworks mentioned above.