Summary
The classes that are applied to nodes should be as automatic as possible. By using a hostname convention and an ENC script, it is possible to have classes applied to nodes without any node-level configuration.
Using LDAP as a backend for class information may be a viable alternative at your enterprise. The LDAP schema included with Puppet can be successfully applied to an OpenLDAP instance or integrated into your existing LDAP infrastructure.
Hiera is a powerful tool for separating data from your module definitions. By utilizing a hierarchy of facts, it is possible to dynamically apply classes to nodes based on their facts.
The important concept in the enterprise is to minimize the customization required in the modules and push that customization up into the node declaration. To separate the code required to deploy your nodes from the specific data, through either LDAP, a custom ENC, or clever use of hiera. If starting from scratch, hiera is the most powerful and flexible solution...
