a simple script to be used via powerdns pipe backend

it is intended to resolve reverse lookups based on the existing A records via the gmysql backend, as the set-ptr option has been removed (see PowerDNS/pdns#7797)

the script requires python3-pymysql aka. PyMySQL

the reverse zones in question should be created in pdns

the script will just work for records registered in the gmysql backend and uses the database connection registered for gmysql in the pdns.conf file

add the following lines to your pdns.conf after the launch+=gmysql line and the other gmysql settings:

zone-cache-refresh-interval=0
launch+=pipe
pipe-regex=^.*\.in-addr\.arpa$
pipe-command=/etc/powerdns/ptr.py

inserting the pipe settings after the gmysql settings ensures that real PTR records will be resolved via the gmysql (or other) backend, and only if none is fpund, the pipe backend will be used.

copy the script to /etc/powerdns/ptr.py

and

chmod 750 /etc/powerdns/ptr.py
chown root:pdns /etc/powerdns/ptr.py

in some cases you might need to add

unix_socket="/var/run/mysqld/mysqld.sock"

as arg to pymysql.connect

the script will log to syslog