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
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Rolling out AMI upgrades with Terraform


Remember that we used data resource "aws_ami" to pull the latest AMI belonging to the AWS account configured in the template? At that moment, we didn't put much effort into it, blindly pulling any existing AMI , as long as it is the latest updated one:

data "aws_ami" "app-ami" { 
  most_recent = true 
  owners = ["self"] 
} 

With Packer building our AMIs, we can put a bit more effort into this resource. We need to make sure that it pulls the image that is suitable for this application. First, simplify Packer template: remove any variables and make sure that the "ami_name" key looks as simple as the following:

"ami_name": "centos-7-base-puppet-{{timestamp}}", 

Rebake the image and then modify Terraform application module to use the following image:

data "aws_ami" "app-ami" { 
  most_recent = true 
  owners = ["self"] 
  filter { 
    name = "name" 
    values = ["centos-7-base-puppet*"] 
  } 
...