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

Showing affected nodes before uploading cookbooks


You tweak a cookbook to support your new server and upload it to your Chef server. Your new node converges just fine and you're happy. Well, until your older production server picks up your modified cookbook during an automated Chef client run and throws a fit. Obviously, you forgot that your old production server was still using the cookbook you tweaked. Luckily, there is the knife preflight command, which can show you all the nodes using a certain cookbook before you upload it to your Chef server.

Getting ready

For the following example, we assume that you have multiple servers with the ntp cookbook in their run list (either directly or via roles).

Use Chef to install the knife-preflight gem. It contains the preflight plugin extending knife with additional commands:

mma@laptop:~/chef-repo $ chef gem install knife-preflight
Fetching gem metadata from https://rubygems.org/
...TRUNCATED OUTPUT...
Installing knife-preflight (0.1.8)

How to do it...