The concept of parameterized classes might have gotten a somewhat tarnished reputation, judging from our coverage of it so far. It allegedly makes it difficult to include classes from multiple places in the manifest, or silently allows it under shifting circumstances. While that is true, you can avoid these issues by relying on Hiera for your class parameterization needs.
Since Puppet's version 3.2, it has been possible to choose the values for any class's parameters right in the Hiera data. Whenever you include a class that has any parameters, Puppet will query Hiera to find a value for each of them. The keys must be named after the class and parameter names, joined by a double colon. Remember ...
