Deploying infrastructure across multiple AWS accounts and regions can be a headache. You need a way to keep things consistent and up-to-date. Imagine having to manually change settings on each individual resource. That’s where CloudFormation StackSets comes in. It lets you manage multiple CloudFormation stacks from a central location.
This article will give you a deep dive into how CloudFormation StackSets can streamline your deployments. You’ll learn the ins and outs of StackSets, how they work, and how to use them to your advantage. This guide is perfect for those who want to scale their infrastructure management on AWS, but lack the practical know-how.
What are CloudFormation StackSets?
CloudFormation StackSets is a service that lets you create, update, or delete stacks across multiple AWS accounts and regions with a single operation. Think of it like a master control for your infrastructure. Instead of managing each stack separately, you manage them as a set. This saves you time and reduces the risk of inconsistencies in your setups.
Here’s a simple way to look at it:
You have multiple houses (AWS accounts) spread across different cities (AWS regions). Instead of going to each house individually to make changes, StackSets lets you control them all from one place. You can remodel the kitchen, repaint the walls, or add a new room. And these changes can be applied to each house at once.
With StackSets, you define a template once. And then you can apply that template to many accounts and regions. This helps you ensure all your environments are uniform and up-to-date.
StackSets are ideal for:
* Multi-account deployments: You might want the same infrastructure in your development, testing, and production accounts.
* Multi-region deployments: If your application needs to be deployed in various geographic locations for better availability or compliance.
* Shared resource setups: Resources like IAM roles, network settings, and security groups, which often need to be consistent across many accounts.
Why Use CloudFormation StackSets?
Why bother with StackSets when you could just use standard CloudFormation stacks? There are several reasons why StackSets can be a game-changer for your multi-environment management:
- Consistency: You get consistent setups across accounts and regions. This is crucial for compliance, security, and avoiding differences that can cause issues.
- Efficiency: Deploy to multiple locations with a single action. This saves you a great deal of time and work over manual setups.
- Centralized Management: Control all deployments from a single place. This simplifies how you manage and audit changes.
- Reduced Errors: Less manual configuration reduces the risk of human error and misconfiguration.
- Simplified Updates: Updates and changes can be rolled out to all deployments at once. This ensures everything stays current and aligned.
Consider this scenario:
You have a central team that manages resources across multiple development teams. Each team has its own AWS account. With StackSets, the central team can define a baseline set of resources. These can include things like monitoring or security rules. And then apply that set to all the development accounts. Each team gets the resources they need. While the central team keeps control over the core infrastructure.
How CloudFormation StackSets Work
Understanding the architecture of StackSets will help you get the most out of the service. Here are the key components:
- StackSet: The main resource that defines your deployment. It contains the CloudFormation template and deployment parameters.
- Template: The CloudFormation template that specifies the resources you want to deploy. This can be a template stored in an S3 bucket or an inline template.
- Parameters: The inputs to the CloudFormation template. These let you customize each stack instance within the set.
- Stack Instance: A single instance of a CloudFormation stack created by the StackSet. Each instance runs in a specific account and region.
- Admin Account: The account where the StackSet is created. This account has management rights for the StackSet.
- Target Accounts: The AWS accounts where stack instances will be created. These accounts must have the appropriate permissions to allow the StackSet to create resources.
Here’s how a typical StackSet deployment works:
1. You create a StackSet in the admin account. You specify the CloudFormation template, parameters, and target accounts and regions.
2. CloudFormation starts creating stack instances in each of the target accounts and regions.
3. Each stack instance operates independently. However, they all use the same CloudFormation template.
4. You can update the StackSet to modify the stacks across all target locations. This keeps your setup uniform.
Setting Up CloudFormation StackSets
Getting your StackSets up and running involves several steps, including setting up permissions, configuring a deployment, and monitoring its execution. Here’s how to get started.
Setting up Permissions
Before you can start creating StackSets, make sure your admin account and target accounts have the proper permissions.
- Admin Account Permissions: The admin account needs to have the ability to create and manage StackSets. This includes permissions to perform actions like
cloudformation:CreateStackSet,cloudformation:UpdateStackSet, andcloudformation:DeleteStackSet. You also need permissions to deploy stack instances. - Target Account Permissions: Target accounts need to have a specific IAM role that allows the StackSet to create and manage resources. This role is named
AWSCloudFormationStackSetExecutionRoleby default and must have the ability to perform actions to create, update, and delete resources within the account.
To set up these permissions:
1. In your admin account, you should create an IAM policy that grants permissions to manage CloudFormation StackSets.
2. Create an IAM role that uses this policy. This role will allow the admin user to create and manage StackSets.
3. In each target account, create an IAM role named AWSCloudFormationStackSetExecutionRole. This role has a policy that allows CloudFormation to manage resources in the account. This includes permissions like ec2:*, s3:*, iam:* etc. Based on the resources being created in the target accounts through CloudFormation.
4. In the trust policy for this target account IAM role, specify the admin account as trusted using its ID.
Creating a StackSet
You can use the AWS Management Console, AWS CLI, or AWS SDKs to create a StackSet. Here’s a basic example of how to do it in the AWS Console:
1. Sign in to the AWS Management Console and go to CloudFormation.
2. Select StackSets from the left navigation pane.
3. Click on Create StackSet.
4. Choose the template source. You can upload a template file, use a sample template, or enter a template URL.
5. Provide a stack set name and description.
6. In the Parameters section, enter the parameters required for the template.
7. In the Deployment Targets section, specify the accounts and regions where you want to create stack instances.
8. Configure the deployment options. You can choose to deploy to all accounts at once or in batches.
9. Review your configuration and click Create StackSet.
Here’s an example of how you can do it in the AWS CLI:
aws cloudformation create-stack-set \
--stack-set-name MyStackSet \
--template-body file://my-template.yaml \
--capabilities CAPABILITY_IAM \
--parameters ParameterKey=MyParameter,ParameterValue=MyValue \
--permission-model SERVICE_MANAGED \
--auto-deployment Enabled=true,RetainStacksOnAccountRemoval=false
In the example above:
* --stack-set-name MyStackSet: gives the StackSet a name.
* --template-body file://my-template.yaml: specifies the location of the CloudFormation template.
* --capabilities CAPABILITY_IAM: is necessary if your template creates IAM resources.
* --parameters ParameterKey=MyParameter,ParameterValue=MyValue: sets parameter values for the template.
* --permission-model SERVICE_MANAGED: specifies that AWS CloudFormation will manage the required IAM permissions.
* --auto-deployment Enabled=true,RetainStacksOnAccountRemoval=false: enables automatic deployments and sets up how stacks behave when you remove an account from your StackSet.
Updating a StackSet
To update your StackSet:
1. Go to the CloudFormation console and select your StackSet.
2. Click Edit StackSet Details.
3. Modify the parameters or template as needed.
4. Select the target accounts you want to update.
5. Choose the deployment options. You can update all stacks at once or in batches.
6. Review your changes and click Update StackSet.
Here is how to update a StackSet using the AWS CLI:
aws cloudformation update-stack-set \
--stack-set-name MyStackSet \
--template-body file://my-updated-template.yaml \
--parameters ParameterKey=MyParameter,ParameterValue=MyUpdatedValue
In the example above:
* --stack-set-name MyStackSet: specifies the StackSet you’re updating.
* --template-body file://my-updated-template.yaml: points to the updated template.
* --parameters ParameterKey=MyParameter,ParameterValue=MyUpdatedValue: sets new parameter values.
Deleting a StackSet
To delete a StackSet:
1. Go to the CloudFormation console and select your StackSet.
2. Click Delete StackSet.
3. Confirm the deletion.
With the AWS CLI, you would do this:
aws cloudformation delete-stack-set \
--stack-set-name MyStackSet
In the example above, --stack-set-name MyStackSet specifies the name of the StackSet you want to delete.
Monitoring StackSets
You can use AWS CloudWatch to monitor the status of your StackSets. This includes the status of the StackSet operations, as well as the status of individual stack instances.
To monitor your StackSets in CloudWatch:
1. Go to the CloudWatch console and select Metrics.
2. Choose CloudFormation Metrics.
3. Filter the metrics by StackSet Name.
4. Check the metrics for operation status, success rates, and errors.
You can also use the AWS CLI:
aws cloudformation describe-stack-set-operation \
--stack-set-name MyStackSet \
--operation-id OperationID
In this example:
* --stack-set-name MyStackSet specifies the name of the StackSet you want to monitor.
* --operation-id OperationID indicates the specific operation you want to check.
Practical Examples of Using StackSets
Let’s dive into a few real-world examples where CloudFormation StackSets can be particularly helpful:
Deploying a Basic Web Application
Imagine you’re running a web application that needs to be deployed across multiple AWS accounts for different environments (development, testing, production). You also need this app deployed in several regions for better performance and resilience. With StackSets, you can manage these deployments easily.
First, you would create a CloudFormation template that defines all the necessary resources. This might include an EC2 instance, an S3 bucket for static content, a database instance, and a load balancer.
You would then create a StackSet using this template. You’d configure the parameters as needed for each environment and region. This might include setting the instance type or database size differently for production.
With StackSets, you can deploy this application across multiple regions. And you can also manage the app in all three environments. If you need to make a change, like updating the instance type, you can apply it to all the Stack Instances from a single update.
Creating Shared IAM Resources
IAM resources often need to be deployed consistently across multiple accounts. This includes roles, policies, and groups. StackSets simplifies the management of these shared resources.
Here’s how to use StackSets for creating shared IAM resources:
1. You create a CloudFormation template that defines the IAM role, the required IAM policy, and possibly some group memberships.
2. You create a StackSet that deploys this template to the target accounts. The admin account would be the one that manages the StackSet.
3. Every target account gets the IAM role defined in the template. This ensures every account has the required permissions to create resources with the IAM role.
4. If a policy needs to change you can just update the StackSet with the new policy and it will be changed in each of the target accounts.
Deploying Networking Infrastructure
Networking infrastructure like VPCs and subnets often needs to be uniform across your multi-account setup. With StackSets you can keep this setup consistent.
To use StackSets for networking:
1. Create a template that defines your VPCs, subnets, route tables, and security groups.
2. Create a StackSet using that template. You can use parameters to customize the IP address ranges for each environment or region.
3. Deploy the StackSet. It creates a consistent network setup in each target account.
4. Updates or changes can be applied easily across all the environments through the StackSet.
Using StackSets with AWS Organizations
AWS Organizations provides a way to centrally manage and govern AWS accounts. When used with StackSets it enhances the way you deploy and manage infrastructure in multi-account deployments.
When you create a StackSet, you can specify the deployment targets as:
* Specific AWS accounts.
* Organizational units (OUs) within your organization.
By targeting OUs, you can ensure that all accounts within a given OU will get the StackSets resources when they are deployed.
When a new account is added to your organization, it will automatically be included in your deployments if you use OUs. This eliminates the need to manually update your StackSets configuration.
You can also use AWS Organizations policies along with StackSets for increased governance:
* Control deployment of StackSets using service control policies (SCPs).
* Ensure that the proper IAM roles are deployed to each account.
* Prevent the manual changes to resources created by StackSets.
Advanced StackSets Concepts
As you become more familiar with StackSets, here are some advanced concepts you might want to explore:
StackSet Drift Detection
StackSet drift detection helps you identify if there are any changes made manually to your StackSet stack instances. Drift happens when a Stack instance’s actual configuration does not match its template. It’s important to detect this to ensure consistency.
When drift is detected you can take corrective actions like:
* Updating the stack instance to align with the template.
* Investigating the changes to determine whether they were intentional or accidental.
To detect drift use the detect-stack-set-drift command in the AWS CLI:
aws cloudformation detect-stack-set-drift \
--stack-set-name MyStackSet
You can use the describe-stack-set-operation command to review the status of the operation:
aws cloudformation describe-stack-set-operation \
--stack-set-name MyStackSet \
--operation-id OperationID
You can also view the drift status in the AWS Management Console.
Automated Deployments
You can configure StackSets to deploy automatically when accounts are added to your organization or when changes are made to the StackSet.
* When you create the StackSet, configure the AutoDeployment parameter.
* This parameter lets you specify whether new stack instances should be automatically created when a new account is added.
* This also lets you retain stacks when you remove accounts from an organizational unit.
* You can use this option to ensure all your resources are kept uniform and up-to-date.
StackSets with Service-Managed Permissions
CloudFormation now supports service-managed permissions for StackSets. Instead of managing IAM roles manually, you let AWS manage the permissions for you.
This approach simplifies management and reduces the risk of misconfiguration. When you select service-managed permissions, AWS takes care of creating and managing the necessary IAM roles on your behalf. This makes setting up StackSets more straightforward.
Stack Instance Management
You have fine-grained control over the stack instances within a StackSet.
* You can deploy stack instances to new accounts and regions.
* You can remove stack instances from specific accounts.
* You can retain the deployed resources even after stack instances are removed. This is useful for preserving data or configurations.
Best Practices When Working with StackSets
Here are some best practices to get the most out of StackSets:
* Start with Simple Templates: Begin with simpler templates and then gradually add complexity. This makes troubleshooting easier.
* Use Parameters: Parameterize your templates to customize deployments for different environments. You should avoid hard-coding values in templates, as it makes them less flexible.
* Version Control your Templates: Keep your templates in a version control system like Git. This allows you to track changes and revert to previous versions if needed.
* Test your Templates: Validate your templates before deploying them. CloudFormation has a validation feature that lets you identify any issues in your template syntax.
* Implement Monitoring: Monitor your deployments using CloudWatch to catch issues early.
* Review Permissions: Regularly review the permissions of your admin accounts, and IAM roles. Make sure you follow the principle of least privilege.
* Use Drift Detection: Check for stack drift on a regular basis to ensure configurations are aligned with the templates.
* Automate Deployments: Configure automated deployments when possible to reduce the effort and risk in deploying infrastructure.
* Properly Name Resources: Use resource naming conventions to avoid conflicts and to make it easier to track resources. Use logical naming conventions to simplify resource management.
Troubleshooting Common Issues
Here are some common issues you might encounter when using CloudFormation StackSets, along with how to fix them:
StackSet Operation Failed
If a StackSet operation fails, check the CloudFormation events for detailed error messages. This will help you understand why the operation failed, and you can start working on fixing the issue.
IAM Permissions Errors
If you get IAM errors, verify that your admin account has the correct permissions to create and manage StackSets. And check if your target accounts have the necessary IAM execution role. Verify that all the required permissions have been granted in your IAM roles and policies.
Template Validation Issues
When you get template validation errors, ensure that your CloudFormation template is valid JSON or YAML. Use the CloudFormation validation feature to test your template syntax.
Stack Instance Creation Errors
When you get errors during the creation of stack instances, check the target account’s event logs for more details on the error. Check the CloudFormation console for any resource specific errors.
Drift Detection Issues
If your drift detection fails, try to update your stack instance to match the current template configuration.
When Not to Use CloudFormation StackSets
While StackSets are very powerful, they are not always the best solution. Here are situations where you might want to consider alternatives:
* Simple Single-Account Deployments: If you only need to deploy resources to a single AWS account, a normal CloudFormation stack is likely simpler.
* Unique Configurations per Account: If you have many resources, and they are completely different across accounts, using a StackSet may be too rigid.
* Very Complex Resource Deployments: If you have deployments that require very specific customization for each account or region, StackSets can be difficult to manage.
* Applications with Frequent, Minor Updates: If the resources in the application require frequent minor updates, then you may not want to use StackSets because of the deployment cycle that is required.
CloudFormation StackSets: The Final Piece of the Puzzle
CloudFormation StackSets is an indispensable tool for managing infrastructure across multiple AWS accounts and regions. With StackSets, you can enhance consistency, improve efficiency, and reduce the risk of human error.
By following this comprehensive guide, you’re equipped to use StackSets to streamline your deployments. You can now create, update, and manage your resources from a single place. This will enable you to manage complex multi-environment infrastructure with greater ease and control.