Kabel

Server that relays messages to websocket clients (i.e. browsers). Useful for sending commands to applications via the command line, for example tell the browser to reload when a file changes.

Installation

npm i -g kabel

Setup autoreload for your web app

Start kabel

# Default port is 3900
kabel

# With different port as option
kabel -p 3010

# or with env variable
KABEL_PORT=3011 kabel

# You can also set the wait in ms before sending the message
kabel -w 500

# or with env variable
KABEL_WAIT=500 kabel

# Quiet output
kabel -q

# or with env variable
KABEL_QUIET=0

You only need one kabel server for all your apps.

Set up web socket connection

Include this on in your web app:

<script>
  var ws = new WebSocket('ws://localhost:3900')
  ws.onopen = function() {
    // Change the name to the name of your app
    // The name should match what you're sending with curl
    ws.send(JSON.stringify({ name: 'app' }))
  }
  ws.onmessage = function() {
    window.location.reload(true)
  }
  ws.onerror = function() {
    console.log('Error connecting to kabel')
  }
</script>

Automatic reload with nodemon

Create a nodemon.json file in your app root direcory that looks like this: kabel.js notify 'http://localhost:3900?name=cfhqadmin'

{
  "events": {
    "restart": "kabel notify 'http://localhost:3900?name=app'"
   }
}

Your application will now reload every time nodemon restarts.

Alternatively you can use curl:

{
  "events": {
    "restart": "curl -X POST -d 'name=app' http://localhost:3900"
   }
}

Send a message to the browser via kabel

# From terminal using kabel
kabel notify 'http://localhost:3900?name=app'

# From terminal using curl
curl -X POST -d 'name=app' http://localhost:3900

Your app should now have reloaded.

License

MIT licensed. Enjoy!