Book Image

Puppet 5 Beginner's Guide - Third Edition

By : John Arundel
Book Image

Puppet 5 Beginner's Guide - Third Edition

By: John Arundel

Overview of this book

Puppet 5 Beginner’s Guide, Third Edition gets you up and running with the very latest features of Puppet 5, including Docker containers, Hiera data, and Amazon AWS cloud orchestration. Go from beginner to confident Puppet user with a series of clear, practical examples to help you manage every aspect of your server setup. Whether you’re a developer, a system administrator, or you are simply curious about Puppet, you’ll learn Puppet skills that you can put into practice right away. With practical steps giving you the key concepts you need, this book teaches you how to install packages and config files, create users, set up scheduled jobs, provision cloud instances, build containers, and so much more. Every example in this book deals with something real and practical that you’re likely to need in your work, and you’ll see the complete Puppet code that makes it happen, along with step-by-step instructions for what to type and what output you’ll see. All the examples are available in a GitHub repo for you to download and adapt for your own server setup.
Table of Contents (21 chapters)
Puppet 5 Beginner's Guide Third Edition
About the Author
About the Reviewer
Customer Feedback

Managing classes with Hiera

In Chapter 3, Managing your Puppet code with Git, we saw how to set up your Puppet repo on multiple nodes and auto-apply the manifest using a cron job and the run-puppet script. The run-puppet script runs the following commands:

cd /etc/puppetlabs/code/environments/production && git pull/opt/puppetlabs/bin/puppet apply manifests/

You can see that everything in the manifests/ directory will be applied on every node. Clearly, Puppet is much more useful when we can apply different manifests on each node; some nodes will be web servers, others database servers, and so on. In fact, we would like to include some classes on all nodes, for general administration, such as managing user accounts, and other classes only on specific nodes. So how do we do that?

Using include with lookup()

Previously, when including classes in our manifest, we've used the include keyword with a literal class name, as in the following example:

include postgresql
include apache