Develop Reference

NodeJS Unable to connect to Websocket Cross origin - "Err 1006"

I have a two webservers both running https with the same certificates, I have a main shard that the user connects to example.com, they retrieve some data and try to connect to an ip address on the 2nd shard via websocket.
But no matter what I configure I get an Error 1006 on the client side when connecting to the 2nd shard. Firefox devtooling gives me multiple errors - ssl_error_bad_cert_domain, SSL_ERROR_RX_RECORD_TOO_LONG.
The certificates are issued and signed, I was wondering where I should go from here. Thanks :)
SHARD2
const options = {
key: './server.key',
cert: './server.cert'
};
var https = require('https').Server(options);
https.listen(443, function () {
// console.log('Https listening on *: 443');
});
let WebSocket = require('ws');
let socket = new WebSocket.Server({ server:https });
socket.on('connection', function (ws, req) {
ws.on('message', (msgRaw) =>{
});
ws.on('close', function(code, reason) {
});
ws.on('error', function(error) {
console.log(error);
ws.close();
});
});
CLIENT
function connect() {
"use strict";
window.WebSocket = window.WebSocket || window.MozWebSocket;
if (!window.WebSocket) {
alert('Your browser doesn\'t support WebSocket');
return;
}
wss = new WebSocket('wss://123.123.123.120/:443');
wss.onmessage = function(event) {
};
wss.onerror = function(event) {
console.log(`wss error: ${JSON.stringify(event)}`);
};
wss.onclose = function(event) {
};
}
Useful sys diagram?

Firefox can’t establish a connection to the server at wss://localhost:8000/

I am using nodejs to run the server, there is no log file
This is my server.js
const https = require('https');
const fs = require('fs');
const ws = require('ws');
const options = {
key: fs.readFileSync('key.pem'),
cert: fs.readFileSync('cert.pem')
};
const wss = new ws.Server({noServer: true});
function accept(req, res) {
// all incoming requests must be websockets
if (!req.headers.upgrade || req.headers.upgrade.toLowerCase() != 'websocket') {
res.end();
return;
}
// can be Connection: keep-alive, Upgrade
if (!req.headers.connection.match(/\bupgrade\b/i)) {
res.end();
return;
}
wss.handleUpgrade(req, req.socket, Buffer.alloc(0), onConnect);
}
function onConnect(ws) {
ws.on('message', function (message) {
let name = message.match(/([\p{Alpha}\p{M}\p{Nd}\p{Pc}\p{Join_C}]+)$/gu) || "Guest";
ws.send(`${name}!`);
//setTimeout(() => ws.close(1000, "Bye!"), 5000);
});
}
https.createServer(options, function (req, res) {
res.writeHead(200);
res.end("hello world\n");
}).listen(8000);
This is my code in react
componentDidMount() {
var connection = new WebSocket('wss://localhost:8000/');
connection.onopen = function(e) {
connection.send("add people");
};
connection.onmessage = function(event) {
// alert(`[message] Data received from server: ${event.data}`);
console.log("output ", event.data);
};
}
While I am trying to connect with web-socket with my jsx file its give me an error which is Firefox can’t establish a connection to the server at wss://localhost:8000/.

Your implementaion needs some changes. In the backend server, you forgot to call the onConnect function. So your ws.on method will never call.
Also, you imported the ws and create a WebSocket server wss, but you add some event listener on ws wrongly, you should add listener on your Websocket instance (wss):
// rest of the codes ...
const was = new ws.Server({noServer: true})
wss.on('connection`) {
// do something here ...
}
// rest of the codes ...
https.createServer(options, () => {
// do something here ...
})
There are some examples of how to create the WebSocket server along with the HTTP server on ws npm page.

Connect multiple Serialports from Arduino with NodeJs

I'm having trouble connecting 4 arduinos using serialports and NodeJs.
When I connect all the ports only one is actually working and collecting the data message while all the others are ignored.
If I declare the serial ports separately they all work fine so the problem is not the Arduino code.
Here's how i declare all the serialports:
// Load HTTP module to create server, handle requests and send back static files (html, css, js)
const http = require('http');
// Load file system module to load files from computer
const fs = require('fs');
// Load path module to read paths from urls
const path = require('path');
// Load serialport module to communicate with arduino
const SerialPort = require('serialport');
// Open up connection with Arduino board
const serial = new SerialPort('/dev/cu.usbserial-1411140', {
baudRate: 115200
}, function() {
console.log('1411140 ready');
})
const SerialPort1 = require('serialport');
const serial1 = new SerialPort1('/dev/cu.usbserial-141120', {
baudRate: 115200
}, function() {
console.log('141120 ready');
})
const SerialPort2 = require('serialport');
const serial2 = new SerialPort2('/dev/cu.usbmodem-1411301', {
baudRate: 115200
}, function() {
console.log('1411301 ready');
})
const SerialPort3 = require('serialport');
const serial3 = new SerialPort3('/dev/cu.usbserial-1411130', {
baudRate: 115200
}, function() {
console.log('1411130 ready');
})
// Define port on which the webpage will be served from
const port = 8080;
This is how i read the arduino data
const io = require('socket.io')(server);
// do stuff when a client connects
io.on('connection', (socket) => {
console.log('a new client connected');
// let the client know that it's connected
socket.emit('greetings', 'You are now connected to the server through Socket IO');
// when receiving data from Arduino, tell the client what to do accordingly
serial.on('data', forwardMessage);
// log if an user disconnects
socket.on('disconnect', () => {
console.log('client disconnected');
// remove listener from Node EventEmitter
serial.removeListener('data', forwardMessage);
});
function forwardMessage(data) {
let message = data.toString().replace(/\n*/, '');
//riceve messaggi dal device corrispondente. Attenzione al nome messo anche sul codice Arduino
if (message.includes('Coinv')) {
socket.emit('CoinvChange', message.substring(7));
}
if (message.includes('Impor')) {
socket.emit('ImporChange', message.substring(7));
}
if (message.includes('Piace')) {
socket.emit('PiaceChange', message.substring(7));
}
if (message.includes('Cresc')) {
socket.emit('CrescChange', message.substring(7));
}
if (message.includes('Press')) {
socket.emit('PressChange', message.substring(7));
}
}
});
And finally this is how i use the message
const socket = io();
// log on browser console when socket is connected to server
socket.on('greetings', (message) => {
console.log(message);
});
// Caricamento Petali
socket.on('CoinvChange', (message) => {
console.log('coinv');
if(message<=6){
getFlowerObject ("petali", 1);
}
if(message>7 && message <=9) {
getFlowerObject ("petali", 2);
}
if(message>12) {
getFlowerObject ("petali", 3);
}
});
// Caricamento Sepali
socket.on('ImporChange', (message) => {
console.log('Impor');
if(message<=2){
getFlowerObject ("sepali", 1);
}
if(message>3 && message <=7) {
getFlowerObject ("sepali", 2);
}
if(message>8) {
getFlowerObject ("sepali", 3);
}
});
Thank you for your help!

Well, in the second snipped, you call just serial.on('data', forwardMessage);, and serial just refers to the firt one.
If you want to interact with the other ones, you have to call the same method also on serial1, serial2 and serial3, which you never use, instead.
As a sidenote, it's enugh to use const SerialPort = require('serialport'); just at the beginning (of the first snippet), then you can do
const serial1 = new SerialPort(...)
...
const serial2 = new SerialPort(...)
...

Nodejs proxy server Cannot set headers after they are sent to the client

I am trying to build a Nodejs server that takes data from another server that contain the data then send it to the client, I am using a proxy structure to handle multiple types of connection.
I am using an HTTP Express server to handle HTTP request and it works fine for the first request after the first request I have an Express error Cannot set headers after they are sent to the
client
_http_outgoing.js:526
throw new ERR_HTTP_HEADERS_SENT('set');
^
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the
client
at ServerResponse.setHeader (_http_outgoing.js:526:11)
at ServerResponse.header (E:\Web\Projects\Color\server\node_modules\express\lib\response.js:771:10)
at ServerResponse.send (E:\Web\Projects\Color\server\node_modules\express\lib\response.js:170:12)
at EventEmitter.<anonymous> (E:\Web\Projects\Color\server\server.js:35:13)
at EventEmitter.emit (events.js:323:22)
at Socket.<anonymous> (E:\Web\Projects\Color\server\server.js:30:22)
at Socket.emit (events.js:323:22)
at addChunk (_stream_readable.js:294:12)
at readableAddChunk (_stream_readable.js:275:11)
at Socket.Readable.push (_stream_readable.js:209:10) {
code: 'ERR_HTTP_HEADERS_SENT'
}
My Express server code:
const express = require("express");
const net = require("net");
const http = require("http");
const login = require("./routes/auth");
const auth = require("./middlewares/verfication");
const info = require("./routes/info");
const events = require("events");
const eventEminter = new events.EventEmitter();
const app = express();
let clientSocket;
app.setClientSocket = (socket) => {
clientSocket = socket;
return true;
};
app.use(express.json());
app.use("/login", login);
app.use("/info", auth, info);
app.get("/", (req, res) => {
let clientData;
console.log("request has been made");
clientSocket.write("GET:/");
clientSocket.on("data", (data) => {
clientData = data.toString();
eventEminter.emit("ed");
console.log(clientData);
});
eventEminter.on("ed", () => {
res.send(clientData);
});
});
module.exports = app;
The clientSocket variable represents the connection with the data server .
Finally here is my server code:
const net = require("net");
const httpServer = require("./server");
//const clientServer = require("./client");
const dotenv = require("dotenv");
dotenv.config();
let clientSocket;
let registeredClient = false;
const proxyServer = net.createServer((socket) => {
socket.on("data", (data) => {
if (!data) {
socket.write("Error in request");
throw new Error("Request message is empty");
}
let request;
try {
request = data.toString();
} catch (error) {
console.log(
new Error("Request message can not be conveted to String")
);
throw error;
}
if (request.includes("HTTP")) {
const httpSocket = new net.Socket();
if (!registeredClient) {
registeredClient = httpServer.setClientSocket(clientSocket);
console.log("Client registered");
}
httpSocket.connect(4444, () => {
console.log("Proxy Connected to http server");
});
httpSocket.on("error", (err) => {
console.error("Proxy error: Could not connect to http server");
throw err;
});
const flushed = httpSocket.write(data, (err) => {
if (err) {
console.error(
"Proxy error :Could not send data to http server"
);
throw err;
}
});
// if (flushed) httpSocket.end();
let response;
httpSocket.on("data", (httpData) => {
if (!httpData) {
console.error(
"Proxy error: unable to retrive data from http server"
);
return;
}
socket.write(httpData.toString());
});
// httpSocket.on("end", () => {
// if (!response) {
// console.error(
// "Proxy error: unable to send response or empty response message"
// );
// return;
// }
// socket.write(response);
// });
} else {
if (!clientSocket) clientSocket = socket;
}
});
socket.on("error", (err) => {
console.error("Proxy error: could not connect with client");
});
});
const port = process.env.PORT || 4000;
proxyServer.listen(port, () => {
console.log(`Proxy Server is running on port ${port}`);
});
httpServer.listen(4444, () => {
console.log("Http server is running on port 4444");
});
thank you for helping.

You are calling res.send() on every "ed" event and you're emitting an "ed" event on every clientSocket.on('data', ...) event. So, as soon as you get a second data event you'll be trying to call res.send() for the second time on the same response. You only get one response per http request. You can't call res.send() more than once for a given http response.
It's unclear how this code is supposed to work since I don't know what you're really trying accomplish here. Perhaps you need to accumulate all the data from the data events and then send one response and then unhook all the listeners do you don't get any more data events for this request. Or, if you want to send the response on the first data event, then just unhook the data and ed listeners after you send the response.
Keep in mind that on a regular socket, you have no control over what data comes in a data event. TCP is a stream protocol and data can come in any size chunks and the chunks it arrives in may not be the exact same as the chunks it was sent in. You would typically have to be looking for some sort of complete packet yourself and be able to assemble or split data events into full packets you can do something with.

Generally this error "Cannot set headers after they are sent to the client" occurs when you are sending multiple response to the server. In your case,
eventEminter.on("ed", () => {
res.send(clientData);
});
As you are using this, you are sending multiple response to server. You should send the response only once. You can use this code instead
eventEminter.once('ed', () => {
res.send(clientData);
});

How to make a socket.io connection between two different interfaces?

I'm actually trying to make a real-time connection between two different apps. I've found a bunch of tutorials about how to make a chat using socket.io, but that doesn't really help me since it's just the same app duplicated in multiple windows.
I'm making a pick & ban overlay for League of Legends in local development. My first thought was to display the empty overlay on one hand and create an interface to manually update it on the other hand. Socket.io seems to be the right thing to use in my case since it can provide new data without having to reload the component.
This is what I wrote in both apps :
const express = require('express');
const socket = require('socket.io');
// App setup
const app = express();
const server = app.listen(4200, function () {
console.log('Listening to requests on port 4200')
});
// Static files
app.use(express.static('public'));
// Socket setup
const io = socket(server);
io.on('connection', function (socket) {
console.log('Made socket connection', socket.id);
socket.on('change', function (data) {
io.sockets.emit('change', data);
});
});
But I fail to connect them as they have to listen to the same port. What am I doing wrong?
(Forgive my bad English and lack of syntax, I'm doing my best here. :p)

I am certainly not an expert on network programming, but as far as I know you need to have one listening app (backend) and another one to connect to it (client). And you define what happens with all the data (messages) that backend recieves (for example sending the messages it recieves to all the clients in the same chat room).
If I am correct to assume you are trying to connect two listening apps?
simple google search of "nodejs socket server client example" revealed this https://www.dev2qa.com/node-js-tcp-socket-client-server-example/ might wanna take your research in this direction

u can try something like this way
var express = require('express');
var socket = require('socket.io');
// App setup
var app = express();
var server = app.listen(8080, () => {
console.log('App started')
})
// Static file
app.use(express.static('public'))
// Socket SetUp
var io = socket(server);
io.on('connection', socket => {
console.log('made the connection')
socket.on('chat',data => {
io.sockets.emit('chat',data)
});
socket.on('typing',data => {
socket.broadcast.emit('typing',data);
});
})
create another file and
var socket = io.connect('http://localhost:8080')
// Elenment
var message = document.getElementById('message');
handle = document.getElementById('handle');
btn = document.getElementById('send');
output = document.getElementById('output');
feedback = document.getElementById('feedback');
// Emit Events
btn.addEventListener('click', () => {
socket.emit('chat', {
message: message.value,
handle: handle.value
})
})
message.addEventListener('keypress', () => {
socket.emit('typing', handle.value)
})
socket.on('chat',data => {
feedback.innerHTML = '';
output.innerHTML += '<p><strong>' + data.handle +': </strong>' +
data.message + '</p>'
})
socket.on('typing', data => {
feedback.innerHTML = '<p><emp>' + data + ' is typing a message... </emp></p>'
})
details are given here node socket chat app

Ok, figured it out. Here's how it works using express and vue together :
First, setup socket.io in your express server js file :
const express = require('express')
const { Server } = require('socket.io')
const http = require('http')
const app = express()
const server = http.createServer(app)
const io = new Server(server, {
cors: {
origin: '*',
methods: ['GET', 'POST', 'REMOVE']
}
})
const PORT = process.env.PORT || 8080
io.on('connection', (socket) => {
console.log('New socket user')
socket.on('SEND_MESSAGE', data => {
console.log('received message in back')
io.emit('MESSAGE', data)
})
})
server.listen(PORT, () => { console.log(`Server started on port : ${PORT}`)})
As you can see we received from the client "SEND_MESSAGE" and we trigger MESSAGE from the server to forward the information to all the clients. The point I was missing is that we bind SEND_MESSAGE on the socked created from the connection but we emit from the io server.
Now you vue part :
import io from 'socket.io-client'
export default {
data() {
return {
messages: [],
inputMessage: null,
socket: io('http://localhost:8080')
}
},
mounted() {
this.socket.on('MESSAGE', data => {
this.messages.push(data)
})
},
methods: {
sendMessage() {
const message = {
senderID: this.myID,
message: this.inputMessage,
sendAt: new Date()
}
this.socket.emit('SEND_MESSAGE', message)
this.inputMessage = null
},
},
}