Connect ddclient and cloudflare

Credit: https://jacobjangles.com/free-ddns-using-ddclient-and-cloudflare/

TLDR:

• ddclient >= 3.9.0

• Config file

cat /etc/ddclient/ddclient.conf
protocol=cloudflare
use=web, web=checkip.dyndns.com, web-skip='IP Address'
login=email@domain.com
password='Cloudflare Global API Key'
zone=chungn.com
wiki.chungn.com,*.chungn.com