UDP Service discover, node.js

client.js

const dgram = require("dgram");



var client = dgram.createSocket("udp4");

client.on("message", function(data, remote){
  
  let str = data.toString("utf8");
  let obj = JSON.parse(str);

  if(obj.service === "http"){
    
    // we found what we wanted
    // dont listen on message events anymore
    client.removeAllListeners("message");
    //socket.connect(); remote.address & obj.port
    
  }
  
  console.log("data from", remote);
  console.log("data", obj);
  
});


client.on('listening', function(){
  
  let addr = this.address();
  console.log("Client waiting for message on %s:%d", addr.address, addr.port)
  
});

client.bind(4512, "255.255.255.255");

server.js

const dgram = require("dgram");


var socket = dgram.createSocket('udp4');

socket.on('listening', function(){
  
    socket.setBroadcast(true);
    
    const message = JSON.stringify({
      service: "http",
      port: 8080
    });
    
    setInterval(function(){
      console.log("Send messae");
      socket.send(message, 0, message.length, 4512, "255.255.255.255");
    }, 1000);
    
});

// bind socket to port
// we dont need a specific outgoing port
socket.bind();