pihole-ufw-dyndns

intro

This is a little script i built myself, so that i can host a "public-faced" Pi-hole for myself. This script resolves defined domains and puts them into ufw (uncomplicated firewall, Ubuntu 22.04).

idea & way to profit

So my Idea was, im constantly switching between two homes and thought why host a pi-hole at each home. I could just host a Pi-hole in the Cloud (like Hetzner or Digital Ocean) and just restrict access to it. Next thing was how to realize this, i tried it through dnsmasq, unbound (probably the best way to do, but i'm not experienced with it) and then iptables. I myself didn't want to work with iptables and ufw was already pre-installed on Ubuntu 22.04.

Actually the script is pretty simple, first step: get existing rulesets and wipe them. I for-loop over every IP i can get with ufw status numbered -> grep 53 -> grep IP-Addresses. Then just loop over this list with my ufw delete command.

Second step: resolve domains and allow them through ufw. New loop that iterates over my config.txt. I resolve the domain with getent and just run it through ufw allow from $ip to any port 53.

Done!

use it yourself

If you want to use it yourself, just create a config.txt and add your DynDNS-Domains or just plain IPs to the script. Now you just need a way to run it every x-Minutes. ONLY IPV4 SUPPORTED atm. It's getting late, have to sleep. Maybe another time i add IPv6 support to my RegEx.

config.txt

### CONFIG FILE FOR PIHOLE UFW DYNDNS
# add your domains separated by space
dyndns_domains="127.0.1 example.com example.de"
# enable (true) or disable (false) logging, this logs to current folder -> logs
logging="false"

crontab

*/5 * * * * /opt/pihole-ufw-dyndns/pihole-ufw-dyndns.sh

I set it up on cron and run it every 5 Minutes.

safety

Please use at your own caution. I know this is probably not the safest approach, but it works. If you have something to contribute or think this is no good idea, please tell me :)