AWS CloudFormation Cheat Sheet
Tags: 30daysofaws, day07, certifieddeveloperassociate, aws
Published: 2022-09-15 03:59:18

![](https://seeklogo.com/images/A/aws-cloudformation-logo-11F173F931-seeklogo.com.png)

## Terminology

| Component   | Description                                                                                                                                                                       |
| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Templates   | The JSON or YAML text file that contains the instructions for building out the AWS environment                                                                                    |
| Stacks      | The entire environment described by the template and created, updated, and deleted as a single unit                                                                               |
| StackSets   | AWS CloudFormation StackSets extends the functionality of stacks by enabling you to create, update, or delete stacks across multiple accounts and regions with a single operation |
| Change Sets | A summary of proposed changes to your stack that will allow you to see how those changes might impact your existing resources before implementing them                            |


## Digest

- A CloudFormation template will consist of a set of resources defined. These resources will be part of a single stack, once built. CloudFormation will treat all the resources as a collection of resources
- CloudFormation supports JSON and YAM for its template languages.
- All ID's are unique to each region, account, and VPC. It is best practice to not embed such IU's inside a CloudFormation template. Instead, define parameters, mappings and conditions to create a dynamic template that could be run across VP's, Regions or even accounts
- Cloudformation stackset vs changeset vs nested stack
- Nested stacks - stacks created as part of other stacks. You create a nested stack within another stack by using the AWS: CloudFormation:Stack resource. For example, assume that you have a load balancer configuration that you use for most of your stacks. Instead of copying and pasting
the same configurations into your templates, you can create a dedicated template for the load balancer. Then, you just use the resource to reference that template from within other templates
- Change Sets will produce a summary of changes and their impact on the resources.
- StackSets is used for deploying or managing template resources across accounts and/or regions.
- Sting, Number, List are supported data type in CFT
- Including lambda function as zipfile parameter in CFT is the easiest way to deploy lambda function
- If stack creation fails, AWS CloudFormation rolls back any changes by deleting the resources that it created.
- Fn:FindInMap to perform a dynamic lookup in Cloud formation template
- Transform section of Cloud formation specifies version of SAM model to use.
- Two templates, one for Intra and one for App.

> - [Practice notes](https://romankurnovskii.com/en/docs/aws-certified-developer-associate/cloudformation/)
> - [Questions](https://dev.to/romankurnovskii/aws-ec2-top-
questions-certified-developer-exam-27oo)