Thanks so much for this. Made this account just to thank you. I have been trying to sort the DHCP server on my pihole for ages and this really helped. Simple when you know what your doing. only thing that threw me was that the docker-file must actually be called "Dockerfile" (case sensitive)
Just wanted to say thank you! This was an exceptionally helpful article.
Since the dhcphelper container's network is configured to run in "host" mode, can it even see bridged network? ie. -s 172.31.0.100 should be invisible to the dhcp-helper docker right?