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

Introducing cfn-init

CloudFormation is a declarative instrument. This means that everything in your template is a declaration of what should be there in CloudFormation’s state. And since you use resource attributes to declare your infrastructure, you must store your configuration in it as well, whether it’s a source code in a Lambda function or UserData in an EC2 launch template, launch configuration, or instance.

Using UserData is a very simple process, but it is hard to declare a configuration in it. In the end, you will do a lot of shell programming, which is not as reliable as configuration management should be.

Luckily, CloudFormation has a set of so-called helper scripts—instruments that can get the data from CloudFormation’s metadata or a stack, process it, and perform operations on your resources. One of them is called cfn-init.

Important note

The cfn-init instrument (and any other helper script) is only included in Amazon Linux AMIs...