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

Automatic syntax-checking with Git hooks


It would be nice if we knew there was a syntax error in the manifest before we even committed it. You can have Puppet check the manifest using the puppet parser validate command:

vagrant@git:~$ puppet parser validate git.pp
Error: Could not parse for environment production: Syntax error at 'require' at /home/vagrant/git.pp:16:3

This is especially useful because a mistake anywhere in the manifest will stop Puppet from running on any node, even on nodes that don't use that particular part of the manifest. So, checking in a bad manifest can cause Puppet to stop applying updates to production for some time, until the problem is discovered, and this could potentially have serious consequences. The best way to avoid this is to automate the syntax check, by using a precommit hook in your version control repo.

How to do it...

Follow these steps:

  1. In your Puppet repo, create a new hooks directory:
t@mylaptop:~/puppet$ mkdir hooks
  1. Create the hooks/check_syntax.sh file...