Cannot connect to Node WebSockets deployment - even with custom domain

Very basic server:

import { createServer } from "http";
import { ChatMessage } from "@chat/types";
import { WebSocketServer } from "ws";

function onSocketError(err) {
  console.error(err);
}

const server = createServer();
const wss = new WebSocketServer({ noServer: true });

wss.on("connection", (ws, request) => {
  console.log("New connection to websocket");

  ws.on("error", console.error);

  ws.on("message", (data) => {
    const msg: ChatMessage = JSON.parse(data.toString());
    console.log(`Received message ${msg} from user ${msg.fromId}`);

    wss.clients.forEach((client) => {
      client.send(JSON.stringify(msg));
    });
  });
});

server.on("upgrade", function upgrade(request, socket, head) {
  console.log("Upgrading to websocket");

  socket.on("error", onSocketError);
  socket.removeListener("error", onSocketError);

  wss.handleUpgrade(request, socket, head, (ws) => {
    wss.emit("connection", ws, request);
  });
});

server.on("listening", () => {
  console.log("Listening on port 8080");
});

server.listen(8080);

import { createServer } from "http";
import { ChatMessage } from "@chat/types";
import { WebSocketServer } from "ws";

function onSocketError(err) {
  console.error(err);
}

const server = createServer();
const wss = new WebSocketServer({ noServer: true });

wss.on("connection", (ws, request) => {
  console.log("New connection to websocket");

  ws.on("error", console.error);

  ws.on("message", (data) => {
    const msg: ChatMessage = JSON.parse(data.toString());
    console.log(`Received message ${msg} from user ${msg.fromId}`);

    wss.clients.forEach((client) => {
      client.send(JSON.stringify(msg));
    });
  });
});

server.on("upgrade", function upgrade(request, socket, head) {
  console.log("Upgrading to websocket");

  socket.on("error", onSocketError);
  socket.removeListener("error", onSocketError);

  wss.handleUpgrade(request, socket, head, (ws) => {
    wss.emit("connection", ws, request);
  });
});

server.on("listening", () => {
  console.log("Listening on port 8080");
});

server.listen(8080);

I connect in the client with

const newWS = new WebSocket("ws://ws.mydomain.com:8080");

    newWS.onopen = () => {
      console.log("Connected to chat server");
    };

    newWS.onerror = (err) => console.error(err);

    newWS.onclose = () => {
      console.log("Disconnected from chat server");
    };

const newWS = new WebSocket("ws://ws.mydomain.com:8080");

    newWS.onopen = () => {
      console.log("Connected to chat server");
    };

    newWS.onerror = (err) => console.error(err);

    newWS.onclose = () => {
      console.log("Disconnected from chat server");
    };

There is no error message but also no console.log() that a connection has been established. Neither on the client nor on the server.

7 Replies

Percy•2y ago

Project ID: 9ebe90c5-ef7a-458e-b833-ac1fc55ce7bb

yannOP•2y ago

9ebe90c5-ef7a-458e-b833-ac1fc55ce7bb

Brody•2y ago

const newWS = new WebSocket("ws://ws.mydomain.com:8080"); 1. you arent using wss as your schema 2. you are specifying a port in the connection string when you shouldn't be websockets does absolutely work on railway, if you dont belive me, check for yourself wss://utilities.up.railway.app/ws

yannOP•2y ago

Hey Brody, thank you for getting back to me. I have changed the connection string and it's still not working. At least throwing an error this time.

websocat wss://ws.mydomain.com
websocat: WebSocketError: WebSocketError: Received unexpected status code (503 Service Unavailable)
websocat: error running

websocat wss://ws.mydomain.com
websocat: WebSocketError: WebSocketError: Received unexpected status code (503 Service Unavailable)
websocat: error running

The server code is very basic - just what I posted above. It works fine in localhost so not sure what to change about it. The subdomain was set using the CNAME record provided by Railway. Interestingly, I have to explicitly define the port 8080 in order to connect to it in localhost (ws://localhost:8080). With the deployed version it works neither with nor without the port defined.

Brody•2y ago

when running on railway you want to be listening on the environment variable PORT you may be starting a websockets server, but this is plenty similar https://docs.railway.app/troubleshoot/fixing-common-errors

yannOP•2y ago

Thank you, that solved it. 🙂 Is this a common code pattern when using a PAAS provider? I would've never thought about this as the problem. Maybe the build process could look out for this and throw an error 🙂

Brody•2y ago

some PAAS platforms will auto scan your app for the port its listening on and update itself, railway doesn’t do this and in a way i guess expects you to read the documentation

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Cannot connect to Node WebSockets deployment - even with custom domain