Book Image

Mastering AWS CloudFormation - Second Edition

By : Karen Tovmasyan
Book Image

Mastering AWS CloudFormation - Second Edition

By: Karen Tovmasyan

Overview of this book

The advent of DevOps and the cloud revolution has compelled software engineers and operations teams to rethink how to manage complex infrastructures and build resilient solutions. With this AWS book, you’ll find out how you can use Infrastructure as Code (IaC) to simplify infrastructure operations and manage the modern cloud with AWS CloudFormation. This guide covers AWS CloudFormation comprehensively, from template structures to developing complex and reusable infrastructure stacks. It takes you through template validation, stack deployment, and handling deployment failures. It also demonstrates the use of AWS CodeBuild and CodePipeline for automating resource delivery and implementing continuous integration and continuous delivery (CI/CD) practices. As you advance, you’ll learn how to modularize and unify your template on the fly using macros or by fixating the version using modules. You’ll create resources outside of AWS with custom resources and catalog them with the CloudFormation registry. Finally, you’ll improve the way you manage the modern cloud environment on AWS by extending CloudFormation through the AWS serverless application model (SAM) and the AWS cloud development kit (CDK). By the end of this book, you’ll have mastered key AWS CloudFormation concepts and will be able to extend its capabilities for developing and deploying your own infrastructure.
Table of Contents (19 chapters)
Free Chapter
1
Part 1: CloudFormation Internals
4
Part 2: Provisioning and Deployment at Scale
9
Part 3: Extending CloudFormation

Using conditional elements

We want to have reusable templates, but sometimes, we need to create a resource in one case and don’t need to create one in another, or perhaps we need to create one with different attributes.

Conditions are handy to solve that kind of problem. They can be used in two ways: to specify the condition under the resource or to use the conditional intrinsic function in the resource properties.

We already know that Conditions is a strict Boolean variable, which is evaluated by parameters and conditional functions. We have already learned how conditions are used in resource declaration (jump to the Going through the internals of the template section if you need a refresher), so let’s look at another useful example.

Say that we have an Auto Scaling group that is built from a launch template. We expect to have a different load on test and production, so we want to adjust the size of the EC2 instance accordingly. For now, we are happy with t3...