ipp-spy

Listen for IPP requests on a given port and proxy requests to a real IPP printer. Allows for spying on the traffic between the client and the server.

Installation

npm install ipp-spy --save

Usage Example

Start an IPP printer spy on port 3000 and proxy all requests to example.com:

var spy = require('ipp-spy')

var opts = {
  port: 3000
  forwardHost: 'example.com', // defaults to localhost
  forwardPort: 631            // default to 631
}

spy(opts, function (operation, document) {
  console.log('New IPP operation:', operation)

  var bytes = 0
  document.on('data', function (chunk) {
    bytes += chunk.length
  })
  document.on('end', function () {
    console.log('Attached document size: %d bytes', bytes)
  })
})

API

The module exposes a generator function which creates a new spy proxy. An EventEmitter is returned:

var server = spy(options[, onOperation])

Options:

• port - the port that the spy should listen on
• forwardHost - the host to forward requests to (defaults to localhost)
• forwardPort - the port to forward requests to (defaults to 631)

The optional onOperation callback argument will be attached to the operation event emitted by the returned EventEmitter.

The returned EventEmitter can emmit the following events:

Event: connection

function (client, server) {}

Emitted every time a new TCP connection is made to the spy proxy.

• client - a TCP socket streaming the data coming from the client
• server - a TCP socket streaming the data returned from the server

Event: operation

function (operation, document) {}

Emitted every time an IPP request is sent to the spy.

The callback is called with two arguments:

• operation - the IPP opperation metadata. See ipp-encoder for details
• document - a readable stream containing the body of the IPP request (i.e. the document being printed)

License

MIT