CODEWITHSUNDEEP
javascriptnode.jssocketsraspberry-pi
aaronfarr
aaronfarr

Reputation: 676

Why does my socket.io app disconnect immediately when run on Raspberry pi?

I am attempting to build a node.js application on a Raspberry Pi which can communicate with a remote socket.io server.

The socket.io server quite simply writes to the console when a new connection is established and when an existing connection is closed.

The socket.io client works as expected when run in a browser.

However, when I run the client code from a Raspberry Pi it connects and immediately terminates. This does not allow me to perform any function such as emitting or receiving.

The on connect event is never fired.

var io = require('/usr/local/lib/node_modules/socket.io-client');
var serverUrl = 'http://remoteserver.com';

console.log('Connecting to ' + serverUrl);
var socket = io.connect(serverUrl);

socket.on('connect', function(socket) {
    console.log('Connection established!');
    console.log(socket.id);

    socket.on('disconnect', function() {
            console.log('Disconnected from server');
    });

});

The code above will output:

Connecting to: http://remoteserver.com

On the server side, the output will show a new connection and eventually a timeout close.

Why is the client on connect event not firing? How can I persist this connection so that I can eventually send inputs to the server?

Upvotes: 1

Views: 1537

Answers (2)

Aidan Hoolachan
Aidan Hoolachan

Reputation: 2379

You only need to call socket.close() when you want to close the connection from the raspberry pi. Also, the socket.io-client documentation does not use the .connect method, but instead calls require('socket.io-client')(serverUrl)

var io = require('/usr/local/lib/node_modules/socket.io-client');
var serverUrl = 'http://remoteserver.com';

console.log('Connecting to ' + serverUrl);
var socket = io(serverUrl);

socket.on('connect', function(socket) {
    console.log('Connection established!');
    console.log(socket.id);
});

socket.on('disconnect', function() {
    console.log('Disconnected from server');
});

//Removed the socket.close() line

Upvotes: 0

jfriend00
jfriend00

Reputation: 707298

Remove the line:

socket.close();

from your code. You are closing the socket immediately. Remember that all the event handlers are asynchronous. They are non-blocking and will be called some time in the future. Meanwhile, the rest of your code runs to completion and thus your socket.close() is executed before your client has any chance to get any events (other than the disconnect event).

If you want to do some stuff and then close the socket, then you need to close the socket only from some event handler that indicates that your operation is complete and you are now done with the socket.

Upvotes: 2

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