You should definitely have a look at Kurento. It provides a WebRTC server infrastructure that allows you to record from a WebRTC feed and much more. You can also find some examples for the application you are planning here. It is really easy to add recording capabilities to that demo, and store the media file in a URI (local disk or wherever).
The project is licensed under LGPL Apache 2.0
EDIT 1
Since this post, we’ve added a new tutorial that shows how to add the recorder in a couple of scenarios
- kurento-hello-world-recording: simple recording tutorial, showing the different capabilities of the recording endpoint.
- kurento-one2one-recording: How to record a one-to-one communication in the media server.
- kurento-hello-world-repository: use an external repository to record the file.
Disclaimer: I’m part of the team that develops Kurento.