You have a Jenkins pipeline to update a CloudFormation stack. The pipeline uses AWS CloudFormation CLI update-stack. Sometimes when the Jenkins job runs, certain AWS resources are recreated, which is not as expected. Your manager asks you to add a step in the pipeline to list the changes that will be applied to the stack. The Jenkins job continues only after the changes are reviewed. How would you modify the Jenkins pipeline?

Answer options:

A.In the new Jenkins step, use AWS CLI --dry-run option to generate a JSON output of the stack update. Review the JSON document before executing the update.
B.Use CloudFormation CLI to detect the drift by uploading the updated template. Review the drift and only update the stack after the drift is approved.
C.As CloudFormation does not have a CLI command to determine the changes, use terraform plan to print the changes and terraform apply to deploy the changes.
D.In the new step, use CloudFormation CLI create-change-set to generate the list of changes that will be applied in the stack. Review the changes before continuing the Jenkins job.

Correct Answer – D
When you need to update a stack, you can use change set to understand how the changes will affect running resources before you implement them. Refer to https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-changesets.html for how to update stacks using change sets.
Option A is incorrect: AWS CLI does not have a --dry-run option so this method cannot resolve the issue.
Option B is incorrect: CloudFormation drift enables you to detect whether a stack`s actual configuration differs from the template. It does not help in this scenario.
Option C is incorrect: Because CloudFormation change set can address this concern. You do not need to change to Terraform.
Option D is CORRECT: CloudFormation change set contains the changes to be applied. Check the reference in
https://docs.aws.amazon.com/cli/latest/reference/cloudformation/create-change-set.html.