Table of Contents
1 Install dnspython
Install python-dnspython package in case of Ubuntu. Install python-dns package in case of CentOS.
$ sudo apt install -y python-dnspython # Ubuntu$ sudo yum install -y python-dns # CentOS
Install dnspython with pip in case of the distribution which has no package for dnspython.
$ sudo pip install dnspython
2 Append A record to zone file
The following script will append A record to zone file.
$ cat dns-append-example.py#!/usr/bin/env pythonimport osimport dns.rdatasetimport dns.rdtypes.IN.Aimport dns.zoneconf = ‘example.zone’hostname = ‘foobar’ipaddr = ‘192.168.11.250’def append(): zone = dns.zone.from_file(conf, os.path.basename(conf)) rdataset = zone.find_rdataset(hostname, dns.rdatatype.A, create=True) rdata = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, ipaddr) rdataset.add(rdata, 86400) zone.to_file(conf)append()
- dns.zone.from_file creates zone object from zone file.
- zone.find_rdataset finds rdataset object which has ‘foobar’ as hostname. If not exist, rdataset object will be created.
- rdata object has A record which has 192.168.11.250 as IP address. rdata object can have other record like NS record.
- Write zone object to zone file.
zone file is as below.
$ cat example.zone$TTL 86400@ IN SOA my.net root.my.net ( 2017021902 3600 900 604800 86400)@ IN NS ubuntu-16.04
Run python script.
$ python dnspython-append-example.py
A record is appended.
$ cat example.zone@ 86400 IN SOA my.net root.my.net 2017021902 3600 900 604800 86400@ 86400 IN NS ubuntu-16.04foobar 86400 IN A 192.168.11.250
3 Remove A record from zone file
The following script will remove A record from zone file.
$ cat dnspython-remove-example.py#!/usr/bin/env pythonimport osimport dns.rdatasetimport dns.rdtypes.IN.Aimport dns.zoneconf = ‘example.zone’hostname = ‘foobar’def remove(): zone = dns.zone.from_file(conf, os.path.basename(conf)) zone.delete_rdataset(hostname, dns.rdatatype.A) zone.to_file(conf)remove()
- zone.delete_rdataset remove rdataset object which has ‘foobar’ as hostname.
zone file is as below.
$ cat example.zone@ 86400 IN SOA my.net root.my.net 2017021902 3600 900 604800 86400@ 86400 IN NS ubuntu-16.04foobar 86400 IN A 192.168.11.250
Run python script.
$ python dnspython-remove-example.py
A record is appended.
$ cat example.zone@ 86400 IN SOA my.net root.my.net 2017021902 3600 900 604800 86400@ 86400 IN NS ubuntu-16.04
