Book Image

Mastering Puppet - Second Edition

By : Thomas Uphill
Book Image

Mastering Puppet - Second Edition

By: Thomas Uphill

Overview of this book

Puppet is a configuration management system and a language. It was written for and by system administrators to manage large numbers of systems efficiently and prevent configuration drifts. Mastering Puppet deals with the issues faced when scaling out Puppet to handle large numbers of nodes. It will show you how to fit Puppet into your enterprise and allow many developers to work on your Puppet code simultaneously. In addition, you will learn to write custom facts and roll your own modules to solve problems. Next, popular options for performing reporting and orchestration tasks will be introduced in this book. Moving over to troubleshooting techniques, which will be very useful. The concepts presented are useful to any size organization. By the end of the book, you will know how to deal with problems of scale and exceptions in your code, automate workflows, and support multiple developers working simultaneously.
Table of Contents (17 chapters)

Creating an example CDN role


We will start by constructing a module for a web server (this example is a cliché). What is a web server? Is a web server an Apache server or a Tomcat server or both, or maybe even Nginx? What file systems are required? What firewall rules should be applied, always? The design problem is figuring out what the commonalities are going to be and where to divide them. In most enterprises, creating a blanket "web server" module won't solve any problems and will potentially generate huge case statements. If your modules follow the roles-and-profiles design pattern, you shouldn't need huge case statements keyed off $::hostname; nodes shouldn't be mentioned in your role module. To elaborate this point further, let's take a look at an example of our companies' Content Delivery Network (CDN) implementation. The nodes in the CDN will be running Nginx.

Note

The use of Nginx for CDN is only given as an example. This in no way constitutes an endorsement of Nginx for this purpose...