Managing AWS resources as a single unit with AWS CloudFormation stacks

A stack is a collection of AWS resources that you can manage as a single unit. In other words, you can create, update, and delete a collection of resources by creating, updating, and deleting stacks.

Creating a stack involves deploying a CloudFormation template that specifies the resources and their configurations, which CloudFormation then provisions and configures.

Updating a stack involves making changes to the template or parameters. CloudFormation compares the changes you submit with the current state of your stack and updates only the changed resources. CloudFormation might interrupt resources or replace updated resources, depending on which properties you update. For more information about resource update behaviors, see Understand update behaviors of stack resources.

CloudFormation provides two methods for updating stacks:

• Change sets – With change sets, you can preview the changes CloudFormation will make to your stack, and then decide whether to apply those changes. Change sets are JSON-formatted documents that summarize the changes CloudFormation will make to a stack. Use change sets when you want to make sure that CloudFormation doesn't make unintentional changes or when you want to consider several options. For example, you can use a change set to verify that CloudFormation won't replace your stack's database instances during an update.

• Direct update – When you directly update a stack, you submit changes and CloudFormation immediately deploys them. Use direct updates when you want to quickly deploy your updates.

Deleting a stack deletes the resources associated with it. A stack, for instance, can include all the resources required to run a web application, such as a web server, a database, and networking rules. If you no longer require that web application, you can simply delete the stack, and all of its related resources are deleted.

Note

You are charged for the stack resources for the time they were operating (even if you deleted the stack right away).

CloudFormation ensures all stack resources are created or deleted as appropriate. Because CloudFormation treats the stack resources as a single unit, they must all be created or deleted successfully for the stack to be created or deleted. If a resource can't be created, CloudFormation rolls the stack back and automatically deletes any resources that were created. If a resource can't be deleted, any remaining resources are retained until the stack can be successfully deleted.

Topics

• Interfaces for managing your stacks

• Create a stack from the CloudFormation console

• View stack information from the CloudFormation console

• Update your stack template

• Understand update behaviors of stack resources

• Update CloudFormation stacks using change sets

• Update stacks directly

• Cancel a stack update

• Delete a stack from the CloudFormation console

• Monitor stack progress

• Roll back your CloudFormation stack on alarm breach with rollback triggers

• Detect unmanaged configuration changes to stacks and resources with drift detection

• Import AWS resources into a CloudFormation stack

• Stack refactoring

• Resource type support

• Use quick-create links to create CloudFormation stacks

• Examples of CloudFormation stack operation commands for the AWS CLI and PowerShell

Interfaces for managing your stacks

You can manage your CloudFormation stacks using the following interfaces:

• CloudFormation console – Provides a web interface that you can use to access your stacks. You can access the CloudFormation console by signing into the AWS Management Console, using the search box on the navigation bar to search for CloudFormation, and then choosing CloudFormation from the search results.

• AWS Command Line Interface – Provides commands for a broad set of AWS services, including CloudFormation, and is supported on Windows, Mac, and Linux. For information about the CloudFormation commands, see cloudformation in the AWS CLI Command Reference.

• AWS Tools for PowerShell – A set of PowerShell modules that are built on the functionality exposed by the SDK for .NET. The Tools for PowerShell enable you to script operations on your AWS resources from the PowerShell command line. You can find the cmdlets for CloudFormation in the AWS Tools for PowerShell Cmdlet Reference.

• Query API – Provides low-level API actions that you call using HTTPS requests. If you make API calls in your application, you must write the code to handle low-level details, such as generating the hash to sign the request. For more information about the API actions for CloudFormation, see Actions in the AWS CloudFormation API Reference.

• AWS SDKs – Provides language-specific APIs and takes care of many of the connection details, such as calculating signatures, handling request retries, and error handling. For more information, see Tools to Build on AWS.

• AWS Cloud Development Kit (AWS CDK) – The AWS CDK is an open-source software development framework that allows you to define AWS infrastructure using familiar programming languages like TypeScript, Python, Java, and .NET. With the CDK, you can model your application resources and then provision them using CloudFormation directly from your integrated development environment (IDE). For more information, see AWS Cloud Development Kit (AWS CDK).