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

Running the same command on many machines at once


A simple problem with so many self-scripted solutions is logging in to multiple boxes in parallel, executing the same command on every box at once. No matter whether you want to check the status of a certain service or look at some critical system data on all boxes, being able to log in to many servers in parallel can save you a lot of time and hassle (imagine forgetting one of your seven web servers when disabling the basic authentication for your website).

How to do it…

Let's try to execute a few simple commands on multiple servers in parallel:

  1. Retrieve the status of the nginx processes from all your web servers (assuming you have at least one host up-and-running, that has the role web_server):

    mma@laptop:~/chef-repo $ knife ssh 'role:web_server' 'sudo sv status nginx'
    www1.prod.example.com run: nginx: (pid 12356) 204667s; run: log: (pid 1135) 912026s
    www2.prod.example.com run: nginx: (pid 19155) 199923s; run: log: (pid 1138) 834124s
    www.test...