AWS Certified SysOps Administrator – Associate (legacy) — Question 191

A company uses AWS CloudFormation to deploy its application infrastructure. Recently, a user accidentally changed a property of a database in a
CloudFormation template and performed a stack update that caused an interruption to the application. A SysOps Administrator must determine how to modify the deployment process to allow the DevOps team to continue to deploy the infrastructure, but prevent against accidental modifications to specific resources.
Which solution will meet these requirements?

Answer options

• A. Set up an AWS Config rule to alert based on changes to any CloudFormation stack. An AWS Lambda function can then describe the stack to determine if any protected resources were modified and cancel the operation.
• B. Set up an Amazon CloudWatch Events event with a rule to trigger based on any CloudFormation API call. An AWS Lambda function can then describe the stack to determine if any protected resources were modified and cancel the operation.
• C. Launch the CloudFormation templates using a stack policy with an explicit allow for all resources and an explicit deny of the protected resources with an action of Update:*.
• D. Attach an IAM policy to the DevOps team role that prevents a CloudFormation stack from updating, with a condition based on the specific Amazon Resource names (ARNs) of the protected resources.

Correct answer: C

Explanation

The correct answer is C because using a stack policy allows for explicit control over which resources can be updated, protecting the specified resources from accidental changes. Options A and B involve monitoring and reacting to changes after they occur, which doesn't prevent the initial modification. Option D restricts updates based on IAM policies but does not provide the granularity of control over specific resources within a stack.