This PHP script will allow you to use your rackspace cloud account as a replacement for the now discontinued free DynDNS domain service.
- Log into mycloud.rackspace.com and add a sub-domain record to your chosen domain which points to your current IP (or any ip, it does not matter at this point)
- Modify dnsupdate.php with your chosen domain, subdomain and rackspace username, rackspace apikey
- chmod write permissions to lastip.txt and execute permission to dnsupdate.php
- To have the script run every 5 minutes just add the following to your crontab:
*/5 * * * * php /home/user/dyndns/dnsupdate.php
The script checks your server's current ip with icanhazip.com and stores your ip in a txt file which it compares on every run. If the ip has changed it will send a DNS modification request to rackspace's DNS API.