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

Creating custom facts


While Facter's built-in facts are useful, it's actually quite easy to add your own facts. For example, if you have machines in different data centers or hosting providers, you could add a custom fact for this so that Puppet can determine whether any local settings need to be applied (for example, local DNS servers or network routes).

How to do it...

Here's an example of a simple custom fact:

  1. Create the modules/facts/lib/facter directory and then create the modules/facts/lib/facter/hello.rb file with the following contents:
Facter.add(:hello) do
     setcode do
    "Hello, world"
  end
end
  1. Use puppet plugin to download the new fact definition:
[root@cookbook ~]# puppet plugin download
Notice: /File[/opt/puppetlabs/puppet/cache/lib/facter/hello.rb]/ensure: defined content as '{md5}f66d5e290459388c5ffb3694dd22388b' 
Downloaded these plugins: /opt/puppetlabs/puppet/cache/lib/facter/hello.rb
  1. Run facter to see your new fact value:
[root@cookbook ~]# facter -p hello
Hello, world

How...