cors error

[GEONWOO]

I want to connect client web page for socketIO and admin-ui to socketIO server.
But the error appears.

When I use this code below, the client web disconnects with cors error.

const io = new Server(httpServer, {
cors: {
origin: "https://admin.socket.io",
},
});
instrument(io, {
auth: false,
});

Of course, I did like this, and "xhr poll error" happens on admin-ui.

const io = new Server(httpServer, {
cors: {
origin: "", // and I did ["https://admin.socket.io",""] instead of this
},
});
instrument(io, {
auth: false,
});

does admin-ui supports only local environment?

[Damien Arrachequesne]

It seems you are missing the credentials: true part:

const { createServer } = require("http");
const { Server } = require("socket.io");
const { instrument } = require("@socket.io/admin-ui");

const httpServer = createServer();

const io = new Server(httpServer, {
  cors: {
    origin: ["https://admin.socket.io"],
    credentials: true
  }
});

instrument(io, {
  auth: false
});

httpServer.listen(3000);

Reference: https://socket.io/docs/v4/admin-ui/#server-side

Could you please check?

[GEONWOO]

It seems you are missing the credentials: true part:

const { createServer } = require("http");
const { Server } = require("socket.io");
const { instrument } = require("@socket.io/admin-ui");

const httpServer = createServer();

const io = new Server(httpServer, {
  cors: {
    origin: ["https://admin.socket.io"],
    credentials: true
  }
});

instrument(io, {
  auth: false
});

httpServer.listen(3000);

Reference: https://socket.io/docs/v4/admin-ui/#server-side

Could you please check?

My mistake. The line "credentials: true" is not there, but I wrote it already.

[Damien Arrachequesne]

@GeonwooDev have you eventually found a solution?

[GEONWOO]

@darrachequesne No, I'm not using admin-ui, but only socketIO.

[MehdiDev]

any updates on this?

[Damien Arrachequesne]

@MehdiMamas unfortunatly I am not able to reproduce the issue.

From my understanding there are two possible explanations:

• either the cors configuration is incorrect (which does not seem to be the case here)
• or the UI is not able to reach the Socket.IO server

Could you please share what gets printed to the console?

[Abolfazgk]

did you find the answer

[neobie]

Getting error as well.

[Damien Arrachequesne]

I have added a few examples in the documentation about the cors option: https://socket.io/docs/v4/server-options/#cors

Does that help?

[LordPhyre]

same issue here.
even with origin: "*" im getting GET http://localhost:8080/socket.io/?EIO=4&transport=polling&t=Oyga8kN net::ERR_FAILED 404 (Not Found)

[LordPhyre]

I have also tried everything in this thread, to no avail.

[szymonc]

Same issue