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

Chapter 4. Modularizing Manifests with Classes and Defined Types

At this point, you have already performed some production-grade tasks with Puppet. You learned how to write standalone manifests and then invoke puppet apply to put them to use. While setting up your first Puppet master and agent, you created a simple example for a node manifest on the master. In a node '<hostname>' block, you created the equivalent of a manifest file. This way, the Puppet master used just this manifest for the specified agent node.

While this is all useful, and of essential importance, it will obviously not suffice for daily business. By working with node blocks that contain sets of resources, you will end up performing lots of copy and paste operations for similar nodes, and the whole construct will become unwieldy very quickly.

This is an unnatural approach to developing Puppet manifests. Despite the great differences to many other languages that you might be familiar with, the Puppet DSL is a programming...