基于dns lib的,https://github.com/andreif/dnslib
https://github.com/anpengapple/apple_dns
https://github.com/circuits/circuits/blob/master/examples/dnsserver.py
https://gist.github.com/pklaus/b5a7876d4d2cf7271873
https://gist.github.com/andreif/6069838
原生的：
https://gist.github.com/Phaeilo/9a176887050a9617605786d66ca03b71
https://github.com/howCodeORG/howDNS/blob/master/dns.py
https://github.com/windwild/python-simple-DNS/blob/master/simpleDNS.py
https://gist.github.com/andreif/6040183
https://gist.github.com/WheresAlice/1397520
https://github.com/jimmykane/Roque-Dns-Server/blob/master/dns.py
https://github.com/obfusk/dns.py/blob/master/dns.py
https://github.com/pathes/fakedns/blob/master/fakedns.py
使用了gevent，twisted，asyncio：
https://github.com/isnowfy/dns
https://gist.github.com/gleicon/1074124
https://github.com/saghul/aiodns
https://github.com/gera2ld/async_dns
https://gist.github.com/kotnik/5722085
没有细看的：
https://github.com/prologic/udns
https://github.com/skyline75489/SimpleDNS
https://github.com/gleicon/python_dns_servers
https://github.com/rjrivero/docker-pydns
https://github.com/daveisadork/PyDevNS
