server.js

// server.js
// where your node app starts

// init project
let _ = require('lodash');
let http = require('http');
let browserify = require('browserify-middleware');
let debug = require('debug')('server');
const express = require("express");

//Express:is used to host files on the server
//You need a package.json to tie the dependencies to the server.js file
const app = express();
let server = http.Server(app);
var io = require('socket.io')(server);

// we've started you off with Express,
// but feel free to use whatever libs or frameworks you'd like through `package.json`.

// http://expressjs.com/en/starter/static-files.html
var DEFAULT_PEER_COUNT = 5;
app.use(express.static("public"));//Get files for static files
app.get('/js/bundle.js', browserify(['debug', 'lodash', 'socket.io-client', 'simple-peer', 'p5', {'./client.js': {run: true}}]));

io.on('connection', function (socket) {
  debug('Connection with ID:', socket.id);
  var peersToAdvertise = _.chain(io.sockets.connected)
    .values()
    .without(socket)
    .sampleSize(DEFAULT_PEER_COUNT)
    .value();
  debug('advertising peers', _.map(peersToAdvertise, 'id'));
  peersToAdvertise.forEach(function(socket2) {
    debug('Advertising peer %s to %s', socket.id, socket2.id);
    socket2.emit('peer', {
      peerId: socket.id,
      initiator: true
    });
    socket.emit('peer', {
      peerId: socket2.id,
      initiator: false
    });
  });

  socket.on('signal', function(data) {
    var socket2 = io.sockets.connected[data.peerId];
    if (!socket2) { return; }
    debug('Proxying signal from peer %s to %s', socket.id, socket2.id);

    socket2.emit('signal', {
      signal: data.signal,
      peerId: socket.id
    });
  });
});

server.listen(process.env.PORT || '3000');