DNS server for convert domain such as 9.9.9.9.ip.recolic.cc or 1-1-1-1.ip.recolic.cc to ip address.
It currently only supports ipv4, but will support ipv6 in the future.
Just run ip2domain.py with python3.
systemctl disable systemd-resolved --now
echo 'nameserver 1.1.1.1' > /etc/resolv.conf
# run this script