🐙 High performance WebRTC SFU implemented with pure Go.
Kraken SFU only supports simple group audio conferencing, more features may be added easily.
Both Unified Plan and RTCP-MUX supported, so that only one UDP port per participant despite the number of participants in a room.
This is the daemon that load balance all engine instances according to their system load, and it will direct all peers in a room to the same engine instance.
The engine handles rooms, all peers in a room should connect to the same engine instance. No need to create rooms, a room is just an ID to distribute streams.
Access the engine with HTTP JSON-RPC, some pseudocode to demonstrate the full procedure.
var roomId = getUrlQueryParameter('room');
var userId = uuidv4();
var trackId;
var pc = new RTCPeerConnection(configuration);
// send ICE candidate to engine
pc.onicecandidate = ({candidate}) => {
rpc('trickle', [roomId, userId, trackId, JSON.stringify(candidate)]);
};
// play the audio stream when available
pc.ontrack = (event) => {
el = document.createElement(event.track.kind)
el.id = aid;
el.srcObject = stream;
el.autoplay = true;
document.getElementById('peers').appendChild(el)
};
// setup local audio stream from microphone
const stream = await navigator.mediaDevices.getUserMedia(constraints);
stream.getTracks().forEach((track) => {
pc.addTrack(track, stream);
});
await pc.setLocalDescription(await pc.createOffer());
// RPC publish to roomId, with SDP offer
var res = await rpc('publish', [roomId, userId, JSON.stringify(pc.localDescription)]);
// publish should respond an SDP answer
var jsep = JSON.parse(res.data.jsep);
if (jsep.type == 'answer') {
await pc.setRemoteDescription(jsep);
trackId = res.data.track;
subscribe(pc);
}
// RPC subscribe to roomId periodically
async function subscribe(pc) {
var res = await rpc('subscribe', [roomId, userId, trackId]);
var jsep = JSON.parse(res.data.jsep);
if (jsep.type == 'offer') {
await pc.setRemoteDescription(jsep);
var sdp = await pc.createAnswer();
await pc.setLocalDescription(sdp);
// RPC anwser the subscribe offer
await rpc('answer', [roomId, userId, trackId, JSON.stringify(sdp)]);
}
setTimeout(function () {
subscribe(pc);
}, 3000);
}
async function rpc(method, params = []) {
const response = await fetch('http://localhost:7000', {
method: 'POST',
mode: 'cors',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({id: uuidv4(), method: method, params: params})
});
return response.json();
}Setup Golang development environment at first.
git clone https://github.com/MixinNetwork/kraken
cd kraken && go build
cp config/engine.example.toml config/engine.toml
ip address # get your network interface name, edit config/engine.toml
./kraken -c config/engine.toml -s engine
Get the source code of either kraken.fm or Mornin, follow their guides to use your local kraken API.
Kraken is built with Pion, we have discussions over their Slack.