Make server.js delete old peer connections on the same IP (#118)

* Make server.js delete old peer connections on the same IP

* fixes from testing on lovelace

* Include the IP in the request

* Add note about one publisher or subscriber at a time

Author: amalnanavati

feedingwebapp/server.js

@@ -12,28 +12,43 @@ const bodyParser = require('body-parser')
 var cors = require('cors')
 const webrtc = require('wrtc')
 
-let senderStream = {}
+let senderStream = {} // key: topic, value: MediaStream
+// NOTE: There is something wrong with the IPs being passed in being
+// all or mostly the same. As a result, in essense this only allows
+// one publisher or subscriber at a time.
+let publishPeers = {} // key: IP4:topic, value: RTCPeerConnection
+let subscribePeers = {} // key: IP4:topic, value: RTCPeerConnection
 
 app.use(bodyParser.json())
 app.use(bodyParser.urlencoded({ extended: true }))
 app.use(cors())
 
 app.post('/subscribe', async ({ body }, res) => {
-  console.log('got subscriber on topic: ' + body.topic)
+  console.log('got subscriber on IP', body.ip, 'for topic', body.topic)
 
   // Configure the peer connection
   const peer = new webrtc.RTCPeerConnection({
     iceServers: [
       {
-        urls: 'stun:stun.stunprotocol.org'
+        urls: 'stun:stun1.l.google.com:19302'
       }
     ]
   })
+
+  // Close any old peers on the same IP address
+  const topic = body.topic
+  const key = body.ip + ':' + topic
+  if (key in subscribePeers) {
+    const senders = subscribePeers[key].getSenders()
+    senders.forEach((sender) => subscribePeers[key].removeTrack(sender))
+    subscribePeers[key].close()
+  }
+  subscribePeers[key] = peer
+
   const desc = new webrtc.RTCSessionDescription(body.sdp)
   await peer.setRemoteDescription(desc)
 
   // Add the publisher's video stream to the subscriber's peer connection
-  const topic = body.topic
   if (topic in senderStream) {
     senderStream[topic].getTracks().forEach((track) => peer.addTrack(track, senderStream[topic]))
   }
@@ -50,19 +65,28 @@ app.post('/subscribe', async ({ body }, res) => {
 })
 
 app.post('/publish', async ({ body }, res) => {
-  console.log('got publisher on topic: ' + body.topic)
+  console.log('got publisher on IP', body.ip, 'for topic', body.topic)
 
   // Configure the peer connection
   const peer = new webrtc.RTCPeerConnection({
     iceServers: [
       {
-        urls: 'stun:stun.stunprotocol.org'
+        urls: 'stun:stun1.l.google.com:19302'
       }
     ]
   })
 
-  // Send the publisher's video stream to all subscribers on that topic
+  // Close any old peers on the same IP address
   const topic = body.topic
+  const key = body.ip + ':' + topic
+  if (key in publishPeers) {
+    const senders = publishPeers[key].getSenders()
+    senders.forEach((sender) => publishPeers[key].removeTrack(sender))
+    publishPeers[key].close()
+  }
+  publishPeers[key] = peer
+
+  // Send the publisher's video stream to all subscribers on that topic
   peer.ontrack = (e) => handleTrackEvent(e, topic)
 
   // Create an answer to the publisher's offer

feedingwebapp/src/Pages/Home/VideoFeed.jsx

@@ -6,7 +6,7 @@ import PropTypes from 'prop-types'
 // Local Imports
 import { CAMERA_FEED_TOPIC, REALSENSE_WIDTH, REALSENSE_HEIGHT } from '../Constants'
 import { useWindowSize } from '../../helpers'
-import { createPeerConnection } from '../../webrtc/webrtc_helpers'
+import { createPeerConnection, closePeerConnection } from '../../webrtc/webrtc_helpers'
 
 /**
  * Takes in an imageWidth and imageHeight, and returns a width and height that
@@ -100,7 +100,7 @@ const VideoFeed = (props) => {
     peer.addTransceiver('video', { direction: 'recvonly' })
 
     return () => {
-      peer.close()
+      closePeerConnection(peer)
     }
   }, [props.topic, props.webrtcURL, videoRef])
 

feedingwebapp/src/webrtc/webrtc_helpers.js

@@ -17,7 +17,7 @@ export function createPeerConnection(url, topic, onTrackAdded, onConnectionEnd)
     const peerConnection = new RTCPeerConnection({
       iceServers: [
         {
-          urls: 'stun:stun.stunprotocol.org'
+          urls: 'stun:stun1.l.google.com:19302'
         }
       ]
     })
@@ -28,9 +28,11 @@ export function createPeerConnection(url, topic, onTrackAdded, onConnectionEnd)
       try {
         const offer = await peerConnection.createOffer()
         await peerConnection.setLocalDescription(offer)
+        const ip = await getIPAddress()
         const payload = {
           sdp: peerConnection.localDescription,
-          topic: topic
+          topic: topic,
+          ip: ip
         }
         console.log('sending payload', payload)
         const { data } = await axios.post(url, payload)
@@ -53,7 +55,7 @@ export function createPeerConnection(url, topic, onTrackAdded, onConnectionEnd)
       if (peerConnection.connectionState === 'failed' || peerConnection.connectionState === 'disconnected') {
         console.error(peerConnection.connectionState, 'Resetting the PeerConnection')
         if (onConnectionEnd) onConnectionEnd()
-        createPeerConnection()
+        // peerConnection = createPeerConnection(url, topic, onTrackAdded, onConnectionEnd)
       }
       console.log('peerConnection.onconnectionstatechange', peerConnection.connectionState)
     }
@@ -69,3 +71,24 @@ export function createPeerConnection(url, topic, onTrackAdded, onConnectionEnd)
     return
   }
 }
+
+/**
+ * Closes the given peer connection.
+ * @param {object} peerConnection The RTCPeerConnection to close.
+ */
+export function closePeerConnection(peerConnection) {
+  if (!peerConnection) return
+  console.log('Closing RTCPeerConnection', peerConnection)
+  if (peerConnection.connectionState !== 'closed') {
+    const senders = peerConnection.getSenders()
+    senders.forEach((sender) => peerConnection.removeTrack(sender))
+    peerConnection.close()
+    console.log('Closed RTCPeerConnection')
+  }
+}
+
+export async function getIPAddress() {
+  const res = await axios.get('https://api.ipify.org/?format=json')
+  console.log(res.data)
+  return res.data.ip
+}