Book Image

Getting Started with Terraform - Second Edition

By : Kirill Shirinkin
1 (1)
Book Image

Getting Started with Terraform - Second Edition

1 (1)
By: Kirill Shirinkin

Overview of this book

Terraform is a tool used to efficiently build, configure, and improve the production infrastructure. It can manage the existing infrastructure as well as create custom in-house solutions. This book shows you when and how to implement infrastructure as a code practices with Terraform. It covers everything necessary to set up the complete management of infrastructure with Terraform, starting with the basics of using providers and resources. It is a comprehensive guide that begins with very small infrastructure templates and takes you all the way to managing complex systems, all using concrete examples that evolve over the course of the book. The book ends with the complete workflow of managing a production infrastructure as code—this is achieved with the help of version control and continuous integration. The readers will also learn how to combine multiple providers in a single template and manage different code bases with many complex modules. It focuses on how to set up continuous integration for the infrastructure code. The readers will be able to use Terraform to build, change, and combine infrastructure safely and efficiently.
Table of Contents (15 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Chapter 3. Resource Dependencies and Modules

Previously, we have managed only one resource with Terraform--a single EC2 instance. Obviously, the real infrastructure is much more complicated than a single server. The more resources you have, the more dependencies between them you have to handle. Also, when the number of resources grows, you will have a hard time managing them via a single huge template file.

In this chapter, we will learn about one of the most important features of Terraform: dependency graph. We will figure out how dependencies work and see it in practice by creating a complete virtual network via AWS VPC. Then, we will learn how to work around some limitations in dependency handling using some of the advanced Terraform features. Finally, when we find out that our template is too big, we will use Terraform modules to Don't Repeat Yourself (DRY) our code.


DRY is a software development principle. Its goal is to reduce the amount of duplication in your code, thus reducing...