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

Writing cross-platform cookbooks


Imagine you have written a great cookbook for your Ubuntu node and now you need to run it on that CentOS server. Ouch! It will most probably fail miserably. The package names might be different and the configuration files are in different places.

Luckily, Chef provides you with a host of features to write cross-platform cookbooks. With just a few simple commands, you can make sure that your cookbook adapts to the platform that your node is running on. Let's look at how to do this...

Getting ready

Make sure you have a cookbook called my_cookbook, and that the run_list of your node includes my_cookbook, as described in the Creating and using cookbooks recipe in Chapter 1, Chef Infrastructure.

How to do it…

Retrieve the node's platform and execute the conditional logic in your cookbook depending on the platform:

  1. Log a message only if your node is on Ubuntu:

    mma@laptop:~/chef-repo $ subl   cookbooks/my_cookbook/recipes/default.rb
    Log.info("Running on ubuntu") if node...