Leveraging the new template engine

In Chapter 6, The Puppet Beginners Advanced Parts, we introduced templates and the ERB template engine. In Puppet 4, an alternative was added: the EPP template engine. The major differences between the template engines are as follows:

• In ERB templates, you cannot specify a variable in Puppet syntax ($variable_name)
• ERB templates will not accept parameters
• In EPP templates, you will use the Puppet DSL syntax instead of Ruby syntax

The EPP template engine requires scoped variables from modules:

# motd file - managed by Puppet 
This system is running on <%= $::operatingsystem %> 

The manifest defines the following local variable: <%= $motd::local_variable %>. The EPP templates also have a unique extension: they can take typed parameters.
To make use of this, a template has to start with a parameter declaration block:

<%- | String...