upgrade event (http.Server)

Event: 'upgrade'

function (request, socket, head) { }

Emitted each time a client requests a http upgrade. If this event isn't listened for, then clients requesting an upgrade will have their connections closed.

• request is the arguments for the http request, as it is in the request event.
• socket is the network socket between the server and client.
• head is an instance of Buffer, the first packet of the upgraded stream, this may be empty.

After this event is emitted, the request's socket will not have a 'data' event listener, meaning you will need to bind to it in order to handle data sent to the server on that socket.