Book Image

Puppet 8 for DevOps Engineers

By : David Sandilands
Book Image

Puppet 8 for DevOps Engineers

By: David Sandilands

Overview of this book

As DevOps and platform engineering drive the demand for robust internal development platforms, the need for infrastructure configuration tools has never been greater. Puppet, a powerful configuration management tool, is widely used by leading enterprises and boasts a thriving open source community. This book provides a comprehensive explanation of both the Puppet language and the platform. It begins by helping you grasp the basic concepts and approach of Puppet as a stateful language, and then builds up to explaining how to structure Puppet code to scale and allow flexibility and collaboration among teams. As you advance, you’ll find out how the Puppet platform allows the management and reporting of infrastructure configuration. The book also shows you how the platform can be integrated with other tooling, such as ServiceNow and Splunk. The concluding chapters help you implement Puppet to fit in heavily regulated and audited environments as well as modern hybrid cloud environments. By the end of this book, you’ll have gained a solid understanding of the capabilities of both the Puppet language and platform, and you will have learned how to structure and scale Puppet to create a platform to provide enterprise-grade infrastructure configuration.
Table of Contents (22 chapters)
1
Part 1 – Introduction to Puppet and the Basics of the Puppet Language
7
Part 2 – Structuring, Ordering, and Managing Data in the Puppet Language
12
Part 3 – The Puppet Platform and Bolt Orchestration
17
Part 4 – Puppet Enterprise and Approaches to the Adoption of Puppet

Understanding node classification

Classification of a node involves finding which environment a node should use, which classes should be applied to a node, and which parameters should be applied to a node. The ideal scenario is to have a single role class applied to a host, but the business logic can be more complicated. This applies to both agent runs to the Puppet Server and puppet apply runs.

Having defined what node classification is, we will now look at the methods that can be used for classification, taking node definitions first as the simplest approach.

Node definitions

The most basic method of node classification is using a node definition, which is a section of Puppet code allowing matching against node names to assign classification information and top-level variables to servers but not the environment. If only using node definitions, the client’s requested environment based on puppet.conf will be used. The node name will be the same as the certname setting...