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

Rolling out AMI upgrades with Terraform


Remember that we used the data resource "aws_ami" to pull the latest AMI belonging to the AWS account configured in the template? At that time, we didn't put much effort into it, blindly pulling any existing AMI , as long as it was 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 the 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 the 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*"] 
  } 
} 

From the aws_instance resource, we can now remove...