A dynamic DNS script (written in PHP) that uses CloudFlare's free DNS and their API to set up a dynamic DNS record pointing to your server.
git clone https://github.com/lyoshenka/cloudflare-ddns.git
cd cloudflare-ddns
cp config.php.skel config.php
### Edit config.php - enter your CloudFlare credentials and domain details
./update.php
If everything works, put it in your crontab.
0 * * * * /path/to/cloudflare-ddns/update.php -s
If you want, you can put this script on a web server and use the "dynamic DNS" option of your router to trigger the IP update.
To do this, first enable API mode by setting an auth_token value in your config.
Then, configure your router to call the script like this: https://example.com/update.php?auth_token=YOUR_TOKEN&ip=IP_ADDR
Uncopyrighted. Do whatever you want. I hope this code makes you rich. Spiritually.
For an even simpler version written in Bash, see this gist.
Use php-cs-fixer like php-cs-fixer fix update.php --rules=@PSR2 to enforce code style.