Book Image

Puppet 5 Cookbook - Fourth Edition

By : Thomas Uphill
Book Image

Puppet 5 Cookbook - Fourth Edition

By: Thomas Uphill

Overview of this book

Puppet is a configuration management system that automates all your IT configurations, giving you control of managing each node. Puppet 5 Cookbook will take you through Puppet's latest and most advanced features, including Docker containers, Hiera, and AWS Cloud Orchestration. Updated with the latest advancements and best practices, this book delves into various aspects of writing good Puppet code, which includes using Puppet community style, checking your manifests with puppet-lint, and learning community best practices with an emphasis on real-world implementation. You will learn to set up, install, and create your first manifests with version control, and also learn about various sysadmin tasks, including managing configuration files, using Augeas, and generating files from snippets and templates. As the book progresses, you'll explore virtual resources and use Puppet's resource scheduling and auditing features. In the concluding chapters, you'll walk through managing applications and writing your own resource types, providers, and external node classifiers. By the end of this book, you will have learned to report, log, and debug your system.
Table of Contents (16 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Writing a custom Hiera5 function


Hiera5 includes the ability to run custom functions at each level of the hierarchy. Unlike earlier versions of Hiera, it is now possible to have different backends for each level of the hierarchy. There are three main types of backends available, depending on how you will access data:

  • data_hash
  • lookup_key
  • data_dig

If you are accessing something locally or where it's possible to read all the data at once, use data_hash. For remote services, use lookup_key and, for databases, use data_dig. More information on custom backends is available at https://puppet.com/docs/puppet/5.3/hiera_custom_backends.html

In this example, we'll create a custom function that queries the Google News API and returns the first headline. 

Getting ready

To start, we'll need to create an API key for our function to contact Google. Obtain your own at https://newsapi.org/register. We'll store the API key in the top-level hiera.yaml configuration. After obtaining your API key, create the following...