How does Puppet handle resources managed with capitalized references?

In Puppet, capitalized references indicate that the resource being referred to is defined as a "resource reference," which is often applied to classes or defined types. This means that when you capitalize a resource name, Puppet expects you to be referencing an existing class or defined type rather than a variable or a local instance of something.

Using capitalized references allows Puppet to differentiate between different types of resources. The naming convention aids in clarity, as it signals to the user that the resource is a defined entity within the Puppet catalog. For instance, if you defined a class named "Webserver" and you reference it in your manifest as "Webserver," Puppet treats this as a call to the class definition rather than as a standard variable.

If capitalized references were not mandatory for classes and defined types, it could lead to confusion between resource types and standard variables, making manifest definitions less clear and potentially leading to runtime errors. Hence, following this convention is critical for ensuring that Puppet correctly interprets the intent behind the resource being referenced.