I made a shell script code to update IP Address of Existing DNS Record.
It checks the current IP of server, and if the public IP has been changed, it checks indicated domain address by using Cloudflare API, updating the new IP to the existing domain record.
I probably sure that it works for all linux distributions, as curl, dig, and jq (need to be installed) commands can be use for all linux distributions, but it needs to be tested more.
I tried to minimize the leak of confidential informations while using this bash shell by unsetting each useless variables and separate configuration file storing credential informations, but if someone can suggest me a better way to improve security of this script, please let me know (via issues of GitHub or comments in here).
Anyone can use my script without any limitation, and I want this work to help some people that stressed by frequenty changing IP address of server (typically for home-server users).
Note: Use crontab to make this bash shell to be started automatically. I am planning to update those information at README.