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)

Ordering containers

The notify and subscribe metaparameters are not the only ones that you can direct at classes and instances of defined types the same holds true for their siblings, before and require. These allow you to define an order for your resources relative to classes, order instances of your defined types, and even order classes among themselves.

The latter works by virtue of the chaining operator:

include firewall 
include loadbalancing 
Class['firewall'] -> Class['loadbalancing'] 

The effect of this code is that all resources from the firewall class will be synchronized before any resource from the loadbalancing class, and failure of any resource in the former class will prevent all resources in the latter from being synchronized.

The chaining arrow cannot just be placed in between the include statements. It works only between resource definitions...