Book Image

Chef Cookbook - Third Edition

By : Matthias Marschall
Book Image

Chef Cookbook - Third Edition

By: Matthias Marschall

Overview of this book

Chef is a configuration management tool that lets you automate your more cumbersome IT infrastructure processes and control a large network of computers (and virtual machines) from one master server. This book will help you solve everyday problems with your IT infrastructure with Chef. It will start with recipes that show you how to effectively manage your infrastructure and solve problems with users, applications, and automation. You will then come across a new testing framework, InSpec, to test any node in your infrastructure. Further on, you will learn to customize plugins and write cross-platform cookbooks depending on the platform. You will also install packages from a third-party repository and learn how to manage users and applications. Toward the end, you will build high-availability services and explore what Habitat is and how you can implement it.
Table of Contents (15 chapters)
Chef Cookbook - Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Raising and logging exceptions in recipes


Running your own cookbooks on your nodes might lead to situations where it does not make any sense to continue the current Chef run. If a critical resource is offline or a mandatory configuration value cannot be determined, it is time to bail out.

However, even if things are not that bad, you might want to log certain events while executing your recipes. Chef offers the possibility to write your custom log messages and exit the current run, if you choose to do so.

In this section, you'll learn how to add log statements and stop Chef runs using exceptions.

Getting ready

You need to have at least one cookbook you can modify and run on a node. The following example will use the ntp cookbook.

How to do it...

Let's see how to add our custom log message to a recipe:

  1. Add log statements to the ntp cookbook's default recipe:

    mma@laptop:~/chef-repo $ subl cookbooks/ntp/recipes/default.rb
    Chef::Log.info('** Going to install the ntp service   now...')
    
    service node...