Book Image

OpenStack Essentials

By : Dan Radez
Book Image

OpenStack Essentials

By: Dan Radez

Overview of this book

Table of Contents (20 chapters)
OpenStack Essentials
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Writing templates


The two core concepts to get started with Heat are stacks and templates. A stack is a collection of resources related to one another and launched by way of a template. A template is a text document definition of a stack. To launch a Heat stack, a Heat template is launched. Let's look at both of these in more depth, starting with templates.

Before we can launch a stack, we need a template that will define the stack. There are two formats of template that you can use to launch a stack in Heat. One is the AWS CloudFormation template format. If you have ever used CloudFormation in AWS, then you would be familiar with this template format. Heat templates are very similar to those used within Amazon Web Services (AWS), and add additional capabilities within OpenStack. The second format is HOT, which stands for Heat Orchestration Template. HOT is a native Heat template format that is written in the YAML Ain't Markup Language syntax. For more examples of both, visit the Heat-templates...