Hi,
Just created a docker for updating dns records on CloudFlare´s free dns service.
It uses a php script to update through CloudFlare´s API, it checks the ip every 120 seconds.
Configuration:
Click "Advanced View" in the upper right corner.
Scroll down and change the Environment Variables to match your CloudFlare details.
Docker-Templates:
https://github.com/macexx/docker-templates
//Regards Mace