webrtc: expose the location header

[rgl]

The suggested WHEP reference client is not able to access the Location header at:

https://github.com/medooze/whip-whep-js/blob/v1.0.3/whep.js#L86-L87

This PR allows the browser to expose that header to the javascript code.

PS: It also needs to use the DELETE method. should I add it to this PR too? or another PR?

Though, this is still not enough to get that client working, as it fails with:

2023/10/03 20:52:30 DEB [WebRTC] [conn [::1]:44266] PATCH /camera_sub/whep
2023/10/03 20:52:30 DEB [WebRTC] [conn [::1]:44266] [c->s] PATCH /camera_sub/whep HTTP/1.1
Host: localhost:8889
Accept: */*
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9,pt-PT;q=0.8,pt;q=0.7
Connection: keep-alive
Content-Length: 105
Content-Type: application/trickle-ice-sdpfrag
Origin: http://localhost:8080
Referer: http://localhost:8080/
Sec-Ch-Ua: "Google Chrome";v="117", "Not;A=Brand";v="8", "Chromium";v="117"
Sec-Ch-Ua-Mobile: ?0
Sec-Ch-Ua-Platform: "Linux"
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-site
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

a=ice-ufrag:w08e
a=ice-pwd:6j8Xfsi7cdr8nYnyvEuoT/vT
m=video 9 RTP/AVP 0
a=mid:0
a=end-of-candidates

2023/10/03 20:52:30 DEB [WebRTC] [conn [::1]:44266] [s->c] HTTP/1.1 400 Bad Request
Access-Control-Allow-Credentials: true
Access-Control-Allow-Origin: *
Server: mediamtx


2023/10/03 20:52:36 DEB [WebRTC] [session 3c3ca543] peer connection state: disconnected
2023/10/03 20:52:36 DEB [WebRTC] [session 3c3ca543] peer connection state: closed
2023/10/03 20:52:36 INF [WebRTC] [session 3c3ca543] closed: peer connection closed

Should I open an new issue in this repository for that problem (and full test application and error)?

[codecov]

Codecov Report

Merging #2453 (93b2f3b) into main (4ba2dc1) will decrease coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2453      +/-   ##
==========================================
- Coverage   61.89%   61.85%   -0.04%     
==========================================
  Files         129      129              
  Lines       14540    14540              
==========================================
- Hits         8999     8994       -5     
- Misses       4872     4876       +4     
- Partials      669      670       +1     

Files	Coverage Δ
internal/core/webrtc_http_server.go	57.74% <100.00%> (ø)

... and 2 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[aler9]

Thanks for providing this PR and for testing the server against the reference WHIP JS implementation. You can either open an issue, or even better, provide PRs to fix compatibility with PATCH and DELETE.

[aler9]

added in v1.2.0