player.js

var socket = io.connect("http://mydomain.ngrok.io.ngrok.io");

document.addEventListener("DOMContentLoaded", function(event) { 
   var media = document.querySelector('video');

    socket.on("doPlayLocal", function (data) {   
        console.log("doPlayLocal called")     
        media.play();
    });

    socket.on("doStopLocal", function (data) {   
        console.log("doStopLocal called")     
        media.pause();
    });
});