AirPrint Proxy

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Advertise AirPrint printers for network printers located outside the subnet using node. GPL-3.0 licensed.

Copyright (C) 2017 Marcus Zhou

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Introduction

This library provides the ability to create a A record which points to an external printer's ip address, and advertise that printer as a AirPrint supported printer. The only parameters really needed to setup is the ip address.

This library can also be used in scenario like the printer is located in another room under a specific subnet that can be reached by ip address but cannot be reached by multicast packets like mdns. By running this proxy on a device located inside the localnet, the phones and computers should be able to discover the printers.

Node: The remote printer needs to support the MIME type image/urf

The library does not provide any kind of translation functions that converts the Apple Raster format to others, which requires the remote printing server to natively support the format.

Requirements & Compatibility

airprint-proxy requires node version greater or equal 8.3.0 to run.

airprint-proxy is compatible with node 10.

Setup

Install as global package:

# For npm users
npm install -g airprint-proxy

# For yarn users
yarn global add airprint-proxy

Install as dependency:

# For npm users
npm install airprint-proxy

# For yarn users
yarn add airprint-proxy

Usage

AirPrint Proxy comes with both Command Line Interface (CLI) and programmable APIs.

Commands

Install AirPrint Proxy as global package to use the command. (See the section above)

Usage: airprint-proxy [...options] <url|ip>

Available options

Short	Full	Description	Default Value
-p	--port	The port of the printing server that clients will be connect to	631
-n	--name	The name of the printer that will be broadcasts to the local network	"Untitled Bonjour Printer"
-l	--location	The notes which will be shown as the location of the printer	""
-q	--queue	The queue on the printing server which clients will be communicating with	"ipp/print"
-c	--color	Broadcast this printer as a color printer	false
-d	--duplex	Broadcast this printer as duplex supported	false
-m	--mime-types	Specify additional supported MIME types beside 'image/urf'.
-o	--txt-record	Add additional txt records. (E.g. -o you=me)
-h	--help	Show help message
-a	--automatic	Automatically resolve and configure printer from ip address	false

Examples

# Automatically resolve the printer's name and capabilities from its ip address
airprint-proxy -a 10.35.0.18

# Broadcast a remote printer at 10.35.0.18 (without asking the printer what it can do)
airprint-proxy 10.35.0.18

# Broadcast the same printer with name "Library Color"
airprint-proxy --name "Library Color" 10.35.0.18

# Broadcast the same printer with name "US Commons" and location "Upper School 1st Floor"
airprint-proxy --name "Library Color" --location "Upper School 1st Floor" 10.35.0.18

APIs

The PrinterProxy object is setup to manage all mdns requests, so be sure to instantiate one every time.

//CommonJS style
const APProxy = require("airprint-proxy");
const PrinterProxy = APProxy.PrinterProxy;
const Printer = APProxy.Printer;

//ES6 style
import { PrinterProxy, Printer } from "airprint-proxy";

let proxy = new PrinterProxy();

Use Printer to represent each printer.

//This is the complex way
let printer = new Printer(
    "10.35.0.18",            //IP Address <required>
    "Library Color Printer", //Name <optional>
    631,                     //Port <optional>
    "Media Center",          //Notes, will be displayed as Location <optional>
    "library-color.local"    //A proper hostname, make sure it is not duplicated <optional>
);

//Use URL to specify queue and include everything
let printer2 = new Printer(
    "ipp://10.20.0.95:631/ipp/print",
     "US Life Center",
     "Upper School 1st Floor");

//Or you can just give the ip address, the name will be set to like
// Untitled Bonjour Printer 10341
let anotherPrinter = new Printer("10.20.0.92");

//Add the printers to make proxy publish those printers
proxy.addPrinter(printer);
proxy.addPrinter(printer2);
proxy.addPrinter(anotherPrinter);

As of 1.2.0, you can let PrinterProxy automatically resolve the name and capabilities of the printer on a remote server supporting unicast dns service discovery. (e.g. a cups server)

You may need to adjust your printer's firewall & mdns responder settings to allow dns sd queries from your address.

//Resolve the printers broadcasting on 10.35.0.18
proxy.resolvePrinter("10.35.0.18");

//The optional callback function accepted in the second argument
proxy.resolvePrinter("10.35.0.18", (error, resolvedPrinters) => {
    //The 'error' parameter is null when successfully resolved the
    // printer, and an 'Error' object on error
    if(error){
        console.error("Error resolving printer", error);
    }
    
    //The 'resolvedPrinters' parameter is null when an error occurred.
    // An array of 'Printer' object on success
})

See src/test.js for more examples.