Book Image

Getting Started with Terraform

By : Kirill Shirinkin
Book Image

Getting Started with Terraform

By: Kirill Shirinkin

Overview of this book

Terraform is a tool used to efficiently build, configure, and improve production infrastructure. It can manage 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 complete management of infrastructure with Terraform, starting with the basics of using providers and resources. This book 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. It finishes with the complete workflow of managing a production infrastructure as code – this is achieved with the help of version control and continuous integration. At the end of this book, you will be familiar with advanced techniques such as multi-provider support and multiple remote modules.
Table of Contents (15 chapters)
Getting Started with Terraform
About the Author
About the Reviewer
Customer Feedback

Understanding variables

If you've ever used any programming language, then you might be familiar with variables already. In most common case, they allow you to assign a value (a number or string or something else) to some hand-picked name and reference this value by this name inside your code. If you need to modify the value, then you just need to do it once, in a place where variable is defined.

Unlike in programming languages, variables in Terraform are more like input data for your templates: you define them before using the template. During the Terraform run, you have zero control over variables. The values of variables never change; you can't modify them inside the template.

In the previous chapter, we already tried variables in order to configure modules. We also learned that our is a module: root module. Let's define some variables for the root module.

It is a common pattern to split variables, template, and outputs into three different files. As you might remember, Terraform...