I would like to route certain traffic via my VPN, however the destination IPs are not static. I just know the hostnames. I am currently just manually updating iptables with the ip address whenever they change, but thats cumbersome even though I have written myself a little update script. I would like to automate this - is it possible to run an external script (with hostname, ip address/ CNAME) whenever an ip is resolved?
That way I could filter the hostname in the script, and update my iptables if necessary. Alternatively filtering in pi-hole would be easier of course (i.e. a nice graphical interface to define the hostnames), but I think that might be harder.
Any suggestions on how to achieve this would be welcome!