How do I send a message to my socket.io websocket from the command line in linux?

Question

Is it possible to send a socket.io message to my localhost server (node) using the command line in linux?

My socket.io code looks like this:

var io = require('socket.io');
var socket;

socket = io.listen(server, {log: false});
server.listen(8081);

socket.sockets.on('connection', function (socket) {
  socket.on('message', function (data) 
  {
    console.log("Received socket message from GUI: "+data);
  }
});

I'd like to send a socket.io message that looks like this: "testControl,loadModels,start" which then triggers some server side logic. Is this possible?

I came across websocketd which seems promising, but it creates a websocket in linux, I just want to send a message to an existing websocket.

Version Info:

• Node Version: v0.10.42
• Socket.IO Version: 1.3.4
• Express Version: 4.12.0

Answer 1

For a more low-level (socket.io-independent) solution you can use my tool websocat.

Example session for communicating with socket.io's chat example:

$ websocat 'wss://socket-io-chat.now.sh/socket.io/?transport=websocket'
< 0{"sid":"yGVElkNCXVgc5w_JOVtc","upgrades":[],"pingInterval":25000,"pingTimeout":60000}
< 40
> 2
< 3
> 42["add user", "websocat"]
< 42["login",{"numUsers":15}]
> 42["new message", "Hello from websocat"]
< 42["typing",{"username":"1223"}]
< 42["new message",{"username":"1223","message":"Reply from browser."}]
< 42["stop typing",{"username":"1223"}]
> 42["new message", "OK, may flood again."]

> denotes messages to be typed.

Answer 2

You can use iocat cli client from npm which is based on Socket.IO.

$ iocat --socketio ws://127.0.0.1:8081
< Hello there

Answer 3

I was able to work around this by doing the following:

1. Create a new endpoint in your server

   app.post('/sendSocketMessage', function(req, res){
     console.log("Request is "+JSON.stringify(req.body));
     socketManager.parse(req.body); //send message directly to your socket parser
     res.status(200).send("OK");
   });
   

2. Send data using curl

   curl --noproxy localhost, 
        -X POST 
        --data "data=testControl,loadModels,start," 
        http://localhost:8081/sendSocketMessage