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)

Accessing and using fact values

You have already seen the use of the processors fact in an example. In the manifest, each fact value is available as a global variable value. That is why you can just use the ::processors expression where you need it.

You will often see conventional uses such as $::processors['count'] or $::networking[‘ip’]. Prefixing the fact name with double colons is highly recommended. The official style guide at https://docs.puppetlabs.com/guides/style_guide.html#namespacing-variables recommends this. The prefix indicates that you are referring to a variable delivered from Facter. Facter variables are put into the Puppet master's top scope.

Some helpful facts have already been mentioned. The processors fact might play a role for your configuration. When configuring some services, you will want to use the machine's networking...