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

Logging debug messages


It can be very helpful when debugging problems if you can print out information at a certain point in the manifest. This is a good way to tell, for example, whether a variable isn't defined or has an unexpected value. Sometimes, it's useful just to know that a particular piece of code has been run. Puppet's notify resource lets you print out such messages.

How to do it...

Define a notify resource in your manifest at the point you want to investigate:

notify { 'Got this far!': }

How it works...

When this resource is applied, Puppet will print out the message:

notice: Got this far!

There's more...

In addition to simple messages, we can output variables within our notify statements. Additionally, we can treat the notify calls the same as other resources, having them require or be required by other resources.

By printing out variable values, you can refer to variables in the message:

notify {"operating system is ${facts['os']['name']}": }

Puppet will interpolate the values in the...