Book Image

Puppet 4 Essentials, Second Edition - Second Edition

By : Felix Frank, Martin Alfke
Book Image

Puppet 4 Essentials, Second Edition - Second Edition

By: Felix Frank, Martin Alfke

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 scalable and portable solutions, not only in terms of software, but also the systems that run it. The free Ruby-based tool Puppet has established itself as the most successful solution to manage any IT infrastructure. Ranging from local development environments through complex data center setups to scalable cloud implementations, Puppet allows you to handle them all with a unified approach. Puppet 4 Essentials, Second Edition gets you started rapidly and intuitively as you’ll put Puppet’s tools to work right away. It will also highlight the changes associated with performance improvements as well as the new language features in Puppet 4. We’ll start with a quick introduction to Puppet to get you managing your IT systems quickly. You will then learn about the Puppet Agent that comes with an all-in-one (AIO) package and can run on multiple systems. Next, we’ll show you the Puppet Server for high-performance communication and passenger packages. As you progress through the book, the innovative structure and approach of Puppet will be explained with powerful use cases. The difficulties that are inherent to a complex and powerful tool will no longer be a problem for you as you discover Puppet's fascinating intricacies. By the end of the book, you will not only know how to use Puppet, but also its companion tools Facter and Hiera, and will be able to leverage the flexibility and expressive power implemented by their tool chain.
Table of Contents (15 chapters)
Puppet 4 Essentials Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Understanding the type system


Being one of the cornerstones of the Puppet model, resources were introduced quite early in Chapter 1, Writing Your First Manifests. Remember how each resource represents a piece of state on the agent system. It has a resource type, a name (or a title), and a list of attributes. An attribute can either be property or parameter. Between the two of them, properties represent distinct pieces of state, and parameters merely influence Puppet's actions upon the property values.

Let's examine resource types in more detail and understand their inner workings. This is not only important when extending Puppet with resource types of your own (which will be demonstrated in Chapter 5, Extending Your Puppet Infrastructure with Modules). It also helps you anticipate the action that Puppet will take, given your manifest, and get a better understanding of both the master and the agent.

First, we take a closer look at the operational structure of Puppet, with its pieces and phases...