Clone the git repository, there is no real installation yet.
Edit powerdyn.conf and adjust the domain and database credentials to match your environment.
Add the following to the ~/.ssh/authorized_keys of the user:
no-agent-forwarding,no-port-forwarding,no-pty,no-X11-forwarding,no-user-rc,command="/usr/local/bin/powerdyn host.powerdyn.example.com" ssh-rsa <SOMESSHKEY>
Add the following to the crontab on the machine you want the dynamic DNS for:
*/5 * * * * ssh -4 -T -i /home/user/.ssh/powerdyn_rsa powerdyn@server.example.com
*/5 * * * * ssh -6 -T -i /home/user/.ssh/powerdyn_rsa powerdyn@server.example.com
If your IPv6 address does not change, just remove the -6 line. powerdyn won't touch the AAAA record then.