Due to a silly networking problem originating from the LVS installation we’re using, we’re stuck with a setup in which machines in the DMZ cannot access themselves via their external addresses. This is a problem for several scripts which refer to their own URL when doing some maintenance. Especially with a certain WordPress MU installation managed by our friends from Interconnect IT, we ran into trouble when they tried to update their WordPress code.
Puppet to the rescue. Although not something I’m especially proud of, I can imagine other using this as an example to fix other problems. What we do is use the wp-config.php from the WordPress installation to get data from the database that WordPress MU connects to. We use a PHP script to retrieve that data and format it in a comma-separated-value list. We then use this output to create a Facter fact, which we use in puppet to create entries in the /etc/hosts file.