This is the documentation for v2.x. Click here for 1.x documentation.
asyncio in pure Python, no third party dependency is required$ pip3 install async_dns
# or
$ pip3 install git+https://github.com/gera2ld/async_dns.git
usage: python3 -m async_dns.resolver [-h] [-n NAMESERVERS [NAMESERVERS ...]] [-t TYPES [TYPES ...]]
hostnames [hostnames ...]
Async DNS resolver
positional arguments:
hostnames the hostnames to query
optional arguments:
-h, --help show this help message and exit
-n NAMESERVERS [NAMESERVERS ...], --nameservers NAMESERVERS [NAMESERVERS ...]
name servers
-t TYPES [TYPES ...], --types TYPES [TYPES ...]
query types, default as `any`
Examples:
# Resolve an IP
$ python3 -m async_dns.resolver www.google.com
$ python3 -m async_dns.resolver -t mx -- gmail.com
# Query via TCP
$ python3 -m async_dns.resolver -n tcp://127.0.0.1 -- www.google.com
# Query via TLS
$ python3 -m async_dns.resolver -n tcps://dns.alidns.com -- www.google.com
# Query from non-standard ports
$ python3 -m async_dns.resolver -n udp://127.0.0.1:1053 -- www.google.com
# Query from HTTPS
$ python3 -m async_dns.resolver -n https://dns.alidns.com/dns-query -- www.google.com
Note: -- is required before hostnames if the previous option can have multiple arguments.
usage: python3 -m async_dns.server [-h] [-b BIND] [--hosts HOSTS] [-x [PROXY [PROXY ...]]]
DNS server by Gerald.
optional arguments:
-h, --help show this help message and exit
-b BIND, --bind BIND the address for the server to bind
--hosts HOSTS the path of a hosts file, `none` to disable hosts, `local` to read from
local hosts file
-x [PROXY [PROXY ...]], --proxy [PROXY [PROXY ...]]
the proxy DNS servers, `none` to serve as a recursive server, `default` to
proxy to default nameservers
Note: TLS and HTTPS are not supported in async_dns server. Consider async-doh for DoH server support.
Examples:
# Start a DNS proxy server on :53
$ python3 -m async_dns.server -b :53 --hosts /etc/hosts
# Start a DNS server over TCP proxy
$ python3 -m async_dns.server -x tcp://114.114.114.114
# Start a DNS recursive server
$ python3 -m async_dns.server -x none
import asyncio
from async_dns.core import types
from async_dns.resolver import ProxyResolver
resolver = ProxyResolver()
res, cached = asyncio.run(resolver.query('www.baidu.com', types.A))
print(res)
The client sends a request to a remote server and returns the message directly. Unlike resolvers, client does not have a cache and does not modify the response.
import asyncio
from async_dns.core import types, Address
from async_dns.resolver import DNSClient
async def query():
client = DNSClient()
res = await client.query('www.google.com', types.A,
Address.parse('8.8.8.8'))
print(res)
print(res.aa)
asyncio.run(query())
ProxyResolver supports routing based on domains:
resolver = ProxyResolver(proxies=[
('*.lan', ['192.168.1.1']), # query 'udp://192.168.1.1:53' for '*.lan' domains
(lambda d: d.endswith('.local'), ['tcp://127.0.0.1']), # query tcp://127.0.0.1:53 for domains ending with '.local'
'8.8.8.8', # equivalent to (None, ['8.8.8.8']), matches all others
])
This library contains a simple implementation of DoH (aka DNS over HTTPS) client with partial HTTP protocol implemented.
If you need a more powerful DoH client based on aiohttp, or a DoH server, consider async-doh.
You can easily add records to the cache with a hosts file or the cache API.
Start a server with a custom hosts file:
$ python3 -m async_dns.server -b :53 --hosts /path/to/custom/hosts
Add some additional records to a resolver:
from async_dns.core import parse_hosts_file, types
for name, qtype, data in parse_hosts_file(hosts):
resolver.cache.add(name, qtype, data)
resolver.cache.add('www.example.com', types.A, ['127.0.0.1'])
$ python3 -m unittest
# Or with tox
$ tox -e py
Logging does not work out of the box in v2. It requires at least minimal logging configuration.
logging.basicConfig(level=logging.INFO)
You can also add a formatter for the logger:
import logging
from async_dns.core import logger
logger.setLevel(logging.INFO)
handler = logging.StreamHandler()
fmt = logging.Formatter('%(asctime)s %(levelname)s: %(message)s')
handler.setFormatter(fmt)
logger.addHandler(handler)
FAQs
Asynchronous DNS client and server
We found that async-dns demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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