Book Image

OpenStack Administration with Ansible

By : Walter Bentley
Book Image

OpenStack Administration with Ansible

By: Walter Bentley

Overview of this book

Most organizations are seeking methods to improve business agility because they have realized just having a cloud is not enough. Being able to improve application deployments, reduce infrastructure downtime, and eliminate daily manual tasks can only be accomplished through some sort of automation. Packed with real-world OpenStack administrative tasks, this book will walk you through working examples and explain how these tasks can be automated using one of the most popular open source automation tools—Ansible. We will start with a brief overview of OpenStack and Ansible and highlight some best practices. Each chapter will provide an introduction to handling various Cloud Operator administration tasks such as creating multiple users/tenants, setting up Multi-Tenant Isolation, customizing your clouds quotas, taking instance snapshots, evacuating compute hosts for maintenance, and running cloud health checks, and a step-by-step tutorial on how to automate these tasks with Ansible.
Table of Contents (18 chapters)
OpenStack Administration with Ansible
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Variables and facts


Anyone who has ever attempted to create some sort of automation code, whether via Bash or Perl scripts, knows that being able to define variables is an essential component. While Ansible does not compare to other programming languages mentioned, it does contain some core programming language features, such as variable substitution.

Variables

To start, let's first define the meaning of variables and use it in the event that this is a new concept. Wikipedia defines it as:

Variable (computer science), a symbolic name associated with a value and whose associated value may be changed.

Using a variable allows you to set a symbolic placeholder in your automation code that you can substitute values for, on each execution. Ansible accommodates defining variables within your playbooks and roles in various ways. When dealing with OpenStack and/or cloud technologies in general, being able to adjust your execution parameters on the fly is critical.

We will see a few ways in which you can...