Leveraging the new template engine

In Chapter 6, Leveraging the Full Toolset of the Language, 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 $local_variable,
      Array  $local_array
| -%>

These parameters are not like variables from Puppet manifests....