pybonjour

Introduction

pybonjour provides a pure-Python interface to Apple Bonjour and compatible DNS-SD libraries (such as Avahi). It allows Python scripts to take advantage of Zero Configuration Networking (Zeroconf) to register, discover, and resolve services on both local and wide-area networks. Since pybonjour is implemented in pure Python, scripts that use it can easily be ported to Mac OS X, Windows, Linux, and other systems that run Bonjour.

pybonjour is free software, distributed under the MIT license.

Download and Requirements

Source packages for pybonjour can be downloaded from http://o2s.csail.mit.edu/download/pybonjour/. The latest version is also available for anonymous checkout from the O2S Subversion respository at svn://o2s.csail.mit.edu/trunk/o2s-libs/network/pybonjour/.

pybonjour requires Python 2.4 or later. It also depends on ctypes (version 1.0.1 or later), which is part of the standard library in Python 2.5 but must be downloaded and installed separately for Python 2.4.

No additional software is required to use pybonjour under Mac OS X. To use it under Windows, the Bonjour for Windows package must be installed on your system. Most Linux systems use Avahi rather than Bonjour for DNS-SD. If this is the case on your system, you'll need to install Avahi's Bonjour compatibility library. (Under Ubuntu, the package to install is libavahi-compat-libdnssd1.) Otherwise, or to use pybonjour under other POSIX systems, you must download, compile, and install Bonjour from source.

Examples

The following scripts are included in the examples directory of the pybonjour source distribution.

Registering a Service

register.py Script

import select
import sys
import pybonjour


name    = sys.argv[1]
regtype = sys.argv[2]
port    = int(sys.argv[3])


def register_callback(sdRef, flags, errorCode, name, regtype, domain):
    if errorCode == pybonjour.kDNSServiceErr_NoError:
        print 'Registered service:'
        print '  name    =', name
        print '  regtype =', regtype
        print '  domain  =', domain


sdRef = pybonjour.DNSServiceRegister(name = name,
                                     regtype = regtype,
                                     port = port,
                                     callBack = register_callback)

try:
    try:
        while True:
            ready = select.select([sdRef], [], [])
            if sdRef in ready[0]:
                pybonjour.DNSServiceProcessResult(sdRef)
    except KeyboardInterrupt:
        pass
finally:
    sdRef.close()

Example Output

$ python register.py TestService _test._tcp 1234
Registered service:
  name    = TestService
  regtype = _test._tcp.
  domain  = local.

Browsing for and Resolving Services

browse_and_resolve.py Script

import select
import sys
import pybonjour


regtype  = sys.argv[1]
timeout  = 5
resolved = []


def resolve_callback(sdRef, flags, interfaceIndex, errorCode, fullname,
                     hosttarget, port, txtRecord):
    if errorCode == pybonjour.kDNSServiceErr_NoError:
        print 'Resolved service:'
        print '  fullname   =', fullname
        print '  hosttarget =', hosttarget
        print '  port       =', port
        resolved.append(True)


def browse_callback(sdRef, flags, interfaceIndex, errorCode, serviceName,
                    regtype, replyDomain):
    if errorCode != pybonjour.kDNSServiceErr_NoError:
        return

    if not (flags & pybonjour.kDNSServiceFlagsAdd):
        print 'Service removed'
        return

    print 'Service added; resolving'

    resolve_sdRef = pybonjour.DNSServiceResolve(0,
                                                interfaceIndex,
                                                serviceName,
                                                regtype,
                                                replyDomain,
                                                resolve_callback)

    try:
        while not resolved:
            ready = select.select([resolve_sdRef], [], [], timeout)
            if resolve_sdRef not in ready[0]:
                print 'Resolve timed out'
                break
            pybonjour.DNSServiceProcessResult(resolve_sdRef)
        else:
            resolved.pop()
    finally:
        resolve_sdRef.close()


browse_sdRef = pybonjour.DNSServiceBrowse(regtype = regtype,
                                          callBack = browse_callback)

try:
    try:
        while True:
            ready = select.select([browse_sdRef], [], [])
            if browse_sdRef in ready[0]:
                pybonjour.DNSServiceProcessResult(browse_sdRef)
    except KeyboardInterrupt:
        pass
finally:
    browse_sdRef.close()

Example Output

$ python browse_and_resolve.py _test._tcp
Service added; resolving
Resolved service:
  fullname   = TestService._test._tcp.local.
  hosttarget = bumble.local.
  port       = 1234
...