Puppet 2.7 Cookbook

Using ERB templates

A template is a text file with a college degree. It can do calculations, execute Ruby code, or reference the values of variables from your Puppet manifests. Anywhere you might deploy a text file using Puppet, you can use a template instead. In the simplest case, a template can just be a static text file. More usefully, you can insert variables into it using ERB (embedded Ruby) syntax. For example:

<%= name %>, this is a very large drink.

If the template is used in a context where the variable $name contains Zaphod Beeblebrox, the template will evaluate as follows:

Zaphod Beeblebrox, this is a very large drink.

This simple technique is very useful for generating lots of files that only differ in the values of one or two variables ...