Book Image

Puppet 5 Essentials - Third Edition

By : Martin Alfke, Felix Frank
Book Image

Puppet 5 Essentials - Third Edition

By: Martin Alfke, Felix Frank

Overview of this book

Puppet is a configuration management tool that allows you to automate all your IT configurations, giving you control over what you do to each Puppet Agent in a network, and when and how you do it. In this age of digital delivery and ubiquitous Internet presence, it's becoming increasingly important to implement scaleable and portable solutions, not only in terms of software, but also the system that runs it. This book gets you started quickly with Puppet and its tools in the right way. It highlights improvements in Puppet and provides solutions for upgrading. It starts with a quick introduction to Puppet in order to quickly get your IT automation platform in place. Then you learn about the Puppet Agent and its installation and configuration along with Puppet Server and its scaling options. The book adopts an innovative structure and approach, and Puppet is explained with flexible use cases that empower you to manage complex infrastructures easily. Finally, the book will take readers through Puppet and its companion tools such as Facter, Hiera, and R10k and how to make use of tool chains.
Table of Contents (10 chapters)

Including classes from defined types

The example_app_config type that was defined in the previous example is supposed to serve a very specific purpose. Therefore, it assumes that the base directory, /etc/example_app, and its subdirectories were managed independently, outside the defined type. This was a sound design, but many defined types are meant to be used from lots of independent classes or other defined types. Such defines need to be self-contained.

In our example, the defined type needs to make sure that the following resources are part of the manifest:

file { [ '/etc/example_app', '/etc/example_app/config.d.enabled' ]:
ensure => 'directory',

Just putting this declaration into the body of the define will lead to duplicate resource errors. Each instance of example_app_config will try to declare the directories by itself. However, we already...