README.rst
1===============================
2Simple DNS resolver for asyncio
3===============================
4
5.. image:: https://secure.travis-ci.org/saghul/aiodns.png?branch=master
6 :target: http://travis-ci.org/saghul/aiodns
7
8aiodns provides a simple way for doing asynchronous DNS resolutions
9with a synchronous looking interface by using `pycares <https://github.com/saghul/pycares>`_.
10
11
12Example
13=======
14
15::
16
17 import asyncio
18 import aiodns
19
20 loop = asyncio.get_event_loop()
21 resolver = aiodns.DNSResolver(loop=loop)
22 f = resolver.query('google.com','A')
23 result = loop.run_until_complete(f)
24 print(result)
25
26
27The following query types are supported: A, AAAA, CNAME, MX, NAPTR, NS, PTR, SOA, SRV, TXT.
28
29The library supports both *asyncio* and *Trollius*.
30
31If you use Python 3 you may use `yield from` statement::
32
33 @asyncio.coroutine
34 def func():
35 result = yield from resolver.query('google.com','A')
36
37For Trollius you should use another syntax like::
38
39 @trollius.coroutine
40 def func():
41 result = yield trollius.From(resolver.query('google.com','A'))
42
43API
44===
45
46The API is pretty simple, three functions are provided in the ``DNSResolver`` class:
47
48* ``query(host, type)``: Do a DNS resolution of the given type for the given hostname. It returns an
49 instance of ``asyncio.Future``. The actual result of the DNS query is taken directly from pycares.
50 As of version 1.0.0 of aiodns (and pycares, for that matter) results are always namedtuple-like
51 objects with different attributes. Please check `the documentation <http://pycares.readthedocs.org/en/latest/channel.html#pycares.Channel.query>`_
52 for the result fields.
53* ``gethostbyname(host, socket_family)``: Do a DNS resolution for the given
54 hostname and the desired type of address family (i.e. ``socket.AF_INET``).
55 While ``query()`` always performs a request to a DNS server,
56 ``gethostbyname()`` first looks into ``/etc/hosts`` and thus can resolve
57 local hostnames (such as ``localhost``). Please check `the documentation
58 <http://pycares.readthedocs.io/en/latest/channel.html#pycares.Channel.gethostbyname>`_
59 for the result fields. The actual result of the call is a ``asyncio.Future``.
60* ``cancel()``: Cancel all pending DNS queries. All futures will get ``DNSError`` exception set, with
61 ``ARES_ECANCELLED`` errno.
62
63
64Running the test suite
65======================
66
67To run the test suite: ``python test_aiodns.py``
68
69
70Author
71======
72
73Saúl Ibarra Corretgé <saghul@gmail.com>
74
75
76License
77=======
78
79aiodns uses the MIT license, check LICENSE file.
80
81
82Python versions
83===============
84
85Python >= 3.4 is natively supported. Python 3.3 supported using the `asyncio package <https://pypi.python.org/pypi/asyncio>`_.
86Older Python versions(2.6 - 3.2) are supported using `trollius <https://pypi.python.org/pypi/trollius>`_.
87
88
89Contributing
90============
91
92If you'd like to contribute, fork the project, make a patch and send a pull
93request. Have a look at the surrounding code and please, make yours look
94alike :-)
95
96
