pdnsupdate

Use RFC2136 to update record on powerdns with a call to external IP resolver

RFC236 part is inspired from certbot_dns_rfc2136

PowerDNS config

You need to configure PowerDNS to allow dynamic update (server wide or per zone) : https://doc.powerdns.com/authoritative/dnsupdate.html#setting-up-dhcpd

For example for per zone settings :

First allow DNSUPDATE for the domain example.com (if yu can determine the IP range your ISP use to restrict update for this range)

select id from domains where name='example.org';
5
insert into domainmetadata(domain_id, kind, content) values(5, ‘ALLOW-DNSUPDATE-FROM’,’0.0.0.0’);

Generate a tsig key (named test for the example)

pdnsutil generate-tsig-key test hmac-md5
Create new TSIG key test hmac-md5 kp4/24gyYsEzbuTVJRUMoqGFmN3LYgVDzJ/3oRSP7ys=

Latest version of powerDNS add automaticaly the key in the database

Link the key for the domain

insert into domainmetadata (domain_id, kind, content) values (5, 'TSIG-ALLOW-DNSUPDATE', 'test');

Test the configuration with nsupdate:

nsupdate <<!
server <ip> <port>
zone example.org
update add test1.example.org 3600 A 203.0.113.1
key test kp4/24gyYsEzbuTVJRUMoqGFmN3LYgVDzJ/3oRSP7ys=
send
!

pdnsupdate config

Copy the config.ini-dist to config.ini and set your value

[DEFAULT]
public_ip_provider = http://ifconfig.me
local_name = <hostname to be updated>

[DNS]
dns_server = <pdsn address>
dns_port = 53
dns_tsig_name = <tsig key name>
dns_tsig_value = <tsig key value>
dns_tsig_algorithm = hmac-md5

[PERSIST]
persit_file = data/persistance.db

I use ifconfig.me as public IP finder, you can use any http(s) site that return only the IP address in the body

you can set the file used to track the previous ip address