monitor.io

Simple remote monitoring and debugging middleware for socket.io.

monitor.io is a module for Node.js that runs as a telnet server, giving a remote client control of and information about sockets connected to an instance of socket.io.

This makes it possible to disconnect, emit, or broadcast data to sockets in a remote terminal without interrupting the Node.js process running socket.io. monitor.io also provides a real-time display of any data attached to a socket with the socket#monitor method.

Installation

$ npm install monitor.io

Usage

var socketio = require('socket.io')(server),
  monitorio = require('monitor.io');

socketio.use(monitorio({ port: 8000 })); // monitor.io started on port 8000

Use telnet to connect to monitor.io and control a real-time list of sockets connected to socket.io.

$ telnet myapp.com 8000

Use hjkl to scroll verticall/horizontally through the list of sockets, e to emit data to a specific socket, and b to broadcast data to all sockets.

Options

localOnly

Enable to prevent connections from any IP except 127.0.0.1. Defaults to false.

To run monitor.io safely in production, enable localOnly and access it via telnet via an ssh connection to your box.

port

The port number for the telnet server to listen on.

remote

Disable to run monitor.io in the current terminal window, without starting a telnet server. Defaults to true.

Monitoring

monitor.io attaches a method named monitor to every socket object. This method attaches data to a socket and tells monitor.io to render this data in the monitor.io terminal window.

Here is an example of how to attach the time that a socket connected to socket.io:

io.on('connection', function(socket) {
  socket.monitor('timeConnected', Date.now());  
});

socket#monitor must be called whenever monitored information changes, such as the score of a player in a real-time game, to force a rerender in the monitor.io window.

socket.on('newHighScore', function(msg) {
  var score = msg.score;
  socket.monitor('highScore', msg.score);
});

The monitor method also accepts an object, and will display every key-value pair in an object.

socket.on('newPlayer', function(msg) {
  var newPlayer = game.createPlayer();
  socket.monitor(newPlayer); // every key-value pair in newPlayer will be shown in the monitor.io terminal window.
});

License

MIT