[[PageOutline(1,Contents)]]

= Twisted Names =

Twisted Names is both a domain name server as well as a client resolver library. Twisted Names comes with an "out of the box" nameserver which can read most BIND-syntax zone files as well as a simple Python-based configuration format. Twisted Names can act as an authoritative server, perform zone transfers from a master to act as a secondary, act as a caching nameserver, or any combination of these. Twisted Names' client resolver library provides functions to query for all commonly used record types as well as a replacement for the blocking gethostbyname() function provided by the Python stdlib socket module.

= Examples =

Running a caching DNS server is as easy as running `twistd`. See `twistd dns --help` for more details

{{{
$ twistd -n dns --port 5354 --recursive --cache
}}}

This is how you can do some name resolution with Twisted Names.

{{{
#!py
$ python -m twisted.conch.stdio
>>> from twisted.names import client
>>> client.getHostByName('twistedmatrix.com')
<Deferred at 0x9dcfbac current result: '66.35.39.65'>
>>> client.lookupMailExchange('twistedmatrix.com')
<Deferred at 0x90eb0ec current result: ([<RR name=twistedmatrix.com type=MX class=IN ttl=86303s auth=False>], [], [<RR name=mail.twistedmatrix.com type=A class=IN ttl=86304s auth=False>])>
}}}

Twisted has pluggable resolvers, the default resolver reads ''/etc/resolv.conf'' (Or ''C:\windows\system\hosts.txt'' on windows), /etc/hosts and has a cache. You can create an alternate resolver to resolve names. Such as in the following example.

{{{
#!py
$ python -m twisted.conch.stdio
>>> from twisted.names import client
>>> resolver = client.createResolver(servers=['8.8.8.8', '8.8.4.4'], hosts='alternate_hosts_file')
>>> resolver.getHostByName('twistedmatrix.com')
<Deferred at 0x9dcfbac current result: '1.2.3.4'>
}}}

You can affect all future name resolution in the reactor and from the `twisted.names.client` by installing a custom resolver into the reactor.

{{{
#!py
from twisted.internet import reactor
from twisted.names import client
reactor.installResolver(client.createResolver(servers=['8.8.8.8', '8.8.4.4'], hosts='alternate_hosts_file'))
}}}

= Download =

See the [wiki:Downloads] page.

= Documentation =

[http://twistedmatrix.com/projects/names/documentation/ Documentation] is available for Twisted Names. An [http://twistedmatrix.com/documents/current/api/ API reference] of Twisted and all subprojects is also available.

= Contact = 

Subscribe to the [http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python twisted-python] mailing list or visit the #twisted channel on irc.freenode.net to ask questions.

[http://twistedmatrix.com/trac/newticket?type=defect&component=names Report a bug] or [http://twistedmatrix.com/trac/newticket?type=enhancement&component=names request a feature] using the issue tracker (registration required), or browse [query:status=new|assigned|reopened&component=names Twisted Names tickets].