Railway•14mo ago

Trying to use sockets with socket.io, works locally but not when deployed

Im using node/express for backend with react frontend. I am trying to establish a socket.io connection between them (they are two different deployments in the same railway project) When I run it locally on my machine, it works perfectly, there's communication and all good. When I deploy it on railway, I get an error, seemingly because for some reason they cannot communicate. Any help/ideas? Ill attach the errors and my code in the next comments

18 Replies

Percy•14mo ago

Project ID: 01e35af8-66ad-42c2-b38f-dab885c67b21

SupamapOP•14mo ago

01e35af8-66ad-42c2-b38f-dab885c67b21

SupamapOP•14mo ago

Error message in chrome

SupamapOP•14mo ago

let app = server()

const httpServer = createServer();

export const io = new Server(httpServer, { cors:{origin:[process.env.SIMPLICAR_FRONT_URL]}, transports: ['websocket', 'polling'], addTrailingSlash: false, path: "/socket.io" });

io.on("connection", (socket) => {
    console.log("SOCKET.IO ON CONNECTION")
});

httpServer.listen(4000, () => {
    console.log(`Servidor de Socket.io escuchando en el puerto ${4000}`);
});

let app = server()

const httpServer = createServer();

export const io = new Server(httpServer, { cors:{origin:[process.env.SIMPLICAR_FRONT_URL]}, transports: ['websocket', 'polling'], addTrailingSlash: false, path: "/socket.io" });

io.on("connection", (socket) => {
    console.log("SOCKET.IO ON CONNECTION")
});

httpServer.listen(4000, () => {
    console.log(`Servidor de Socket.io escuchando en el puerto ${4000}`);
});

Code for the backend

const socket = io(process.env.NEXT_PUBLIC_SOCKETIO_ENDPOINT)


  socket.on('plate-scrapper-updated', (plate) => {
    console.log("Socket recived 1", plate)
    updatePlateScrapper(plate)
    console.log('Salio de updatePlateScrapper')

  })

const socket = io(process.env.NEXT_PUBLIC_SOCKETIO_ENDPOINT)


  socket.on('plate-scrapper-updated', (plate) => {
    console.log("Socket recived 1", plate)
    updatePlateScrapper(plate)
    console.log('Salio de updatePlateScrapper')

  })

This is the frontend code I dont think its a problem with the code, since it works perfectly in localhost

Brody•14mo ago

its the code, read this please https://docs.railway.app/troubleshoot/fixing-common-errors

SupamapOP•14mo ago

Alright, so the PORT variable is 80 in the backend. Im using that port for the express hosting

    let app: Express = express();

    const HOST = process.env.HOST || 'localhost';
    const PORT = process.env.PORT || '3000';
    const DBURI = process.env.MONGO_URI || ''

    const link = "http://" + HOST + ":" + PORT.toString()

    await InitializeMiddleWare.InitializeCommonMiddleware(app)
    await InitializeRoutes.Initialize(app, link)
    await InitializeMiddleWare.InitializeErrorHandlingMiddleware(app)
    await InitializeDB.Connect(DBURI)

    app.listen(PORT, () => {
        logger.info(`Server  started listening at ${HOST} on ${PORT} port.`)
    })

    let app: Express = express();

    const HOST = process.env.HOST || 'localhost';
    const PORT = process.env.PORT || '3000';
    const DBURI = process.env.MONGO_URI || ''

    const link = "http://" + HOST + ":" + PORT.toString()

    await InitializeMiddleWare.InitializeCommonMiddleware(app)
    await InitializeRoutes.Initialize(app, link)
    await InitializeMiddleWare.InitializeErrorHandlingMiddleware(app)
    await InitializeDB.Connect(DBURI)

    app.listen(PORT, () => {
        logger.info(`Server  started listening at ${HOST} on ${PORT} port.`)
    })

Brody•14mo ago

you are also trying to specify a port in the socket.io url, you can only access railway services from port 443, so you shouldnt have any port in the url

SupamapOP•14mo ago

Alright, so should I aim it at 443, or just not specify a port? And should my socket.io port be 443 in the backend httpServer.listen?

Brody•14mo ago

Alright, so should I aim it at 443, or just not specify a port?

you are using https, so 443 is implied, correct, dont specify a port

And should my socket.io port be 443 in the backend httpServer.listen?

nope, please read the entire doc page i linked

SupamapOP•14mo ago

I had read it, but I'll read it again anyways, thanks!

Brody•14mo ago

no skim reading

SupamapOP•14mo ago

Alright so what I can only conclude is that "Thus, your web server must listen on host 0.0.0.0 and the port that Railway provides in the PORT environment variable." Means that I can only have one service with one port, and all requests will be sent to the default port? So i cant have my express app in the default port and then have the socket.io service on a different port So from that, my only idea is to split the socket.io functionality into a separate service/github repo

Medim•14mo ago

Or you can make both work on the same port and in the same service, expressjs can use ur socketio instance

SupamapOP•14mo ago

oh, you can?

Medim•14mo ago

const app = express();
var http = require("http");
var server = http.createServer(app);

const io = require("socket.io")(server, {
  cors: {
    origin: "*",
    methods: ["GET", "POST"],
  },
});
io.on("connection", async (socket) => {
  console.log("Connected: ", socket.id);
  });
});

server.listen(env.PORT);

const app = express();
var http = require("http");
var server = http.createServer(app);

const io = require("socket.io")(server, {
  cors: {
    origin: "*",
    methods: ["GET", "POST"],
  },
});
io.on("connection", async (socket) => {
  console.log("Connected: ", socket.id);
  });
});

server.listen(env.PORT);

SupamapOP•14mo ago

interesting, ill give it a try, thanks!

Medim•14mo ago

expressjs will use it on yourip/socketio/ or something like that as your websocket connection endpoint, but normally socketio itself handles that for you afaik atleast clientside while connecting to the socketio in the backend sorry if my explanation is a bit bad, u better read the documentation lol

SupamapOP•14mo ago

It kinda makes sense either that, or split it into a completely different service I guess, that ONLY hosts the socket.io connections

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Trying to use sockets with socket.io, works locally but not when deployed