Connecting to an already established UNIX socket with node.js?

Question

I am working on a node.js application that will connect to a UNIX socket (on a Linux machine) and facilitate communication between a web page and that socket. So far, I have been able to create socket and communicate back and forth with this code in my main app.js:

var net = require('net');
var fs = require('fs');
var socketPath = '/tmp/mysocket';

fs.stat(socketPath, function(err) {
    if (!err) fs.unlinkSync(socketPath);
    var unixServer = net.createServer(function(localSerialConnection) {
        localSerialConnection.on('data', function(data) {
            // data is a buffer from the socket
        });
        // write to socket with localSerialConnection.write()
    });

unixServer.listen(socketPath);
});

This code causes node.js to create a UNIX socket at /tmp/mysocket and I am getting good communication by testing with nc -U /tmp/mysocket on the command line. However...

I want to establish a connection to an already existing UNIX socket from my node.js application. With my current code, if I create a socket from the command line (nc -Ul /tmp/mysocket), then run my node.js application, there is no communication between the socket and my application (The 'connect' event is not fired from node.js server object).

Any tips on how to go about accomplishing this? My experiments with node.js function net.createSocket instead of net.createServer have so far failed and I'm not sure if that's even the right track.

user149341 · Accepted Answer · 2013-12-28 00:15:48Z

18

The method you're looking for is net.createConnection(path):

var client = net.createConnection("/tmp/mysocket");

client.on("connect", function() {
    ... do something when you connect ...
});

client.on("data", function(data) {
    ... do stuff with the data ...
});

answered Dec 28, 2013 at 0:15

user149341

Sign up to request clarification or add additional context in comments.

3 Comments

user149341 Over a year ago

@aleclarson That isn't a socket. It's a URL.

aleclarson Over a year ago

Fair enough, but I still need to connect to it with net.connect if possible.

ericek111 Over a year ago

Is there a way to interface this with express.js web server?

anon · Accepted Answer · 2020-02-01 05:05:37Z

2

I was just trying to get this to work with Linux's abstract sockets and found them to be incompatible with node's net library. Instead, the following code can be used with the abstract-socket library:

const abstract_socket = require('abstract-socket');

let client = abstract_socket.connect('\0my_abstract_socket');

client.on("connect", function() {
    ... do something when you connect ...
});

client.on("data", function(data) {
    ... do stuff with the data ...
});

answered Feb 1, 2020 at 5:05

anon

Comments

nikallass · Accepted Answer · 2018-04-10 21:59:27Z

-5

You can also connect to a socket like this:

http://unix:/path/to/my.sock:

answered Apr 10, 2018 at 21:59

nikallass

71 bronze badge

1 Comment

Anubhab Over a year ago

Please follow this discussion to get a quick and basic understanding of the differences between Unix Sockets and TCP sockets. serverfault.com/questions/124517/…

Collectives™ on Stack Overflow

Connecting to an already established UNIX socket with node.js?

3 Answers 3

3 Comments

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related