Which strategy will meet these requirements?
Add a stage to the CodePipeline pipeline between the source and deploy stages. Use AWS CodeBuild to create a runtime environment and build commands in the buildspec file to invoke test scripts. If errors are found, use the aws deploy stop-deployment command to stop the deployment.
Add a stage to the CodePipeline pipeline between the source and deploy stages. Use this stage to invoke an AWS Lambda function that will run the test scripts. If errors are found, use the aws deploy stop-deployment command to stop the deployment.
Add a hooks section to the CodeDeploy AppSpec file. Use the AfterAllowTestTraffic lifecycle event to invoke an AWS Lambda function to run the test scripts. If errors are found, exit the Lambda function with an error to initiate rollback.
Add a hooks section to the CodeDeploy AppSpec file. Use the AfterAllowTraffic lifecycle event to invoke the test scripts. If errors are found, use the aws deploy stop-deployment CLI command to stop the deployment.
Explanations:
Adding a stage between the source and deploy stages with AWS CodeBuild to run tests is a viable option, but it does not meet the requirement to test the green version after it is deployed. This option tests before deployment, which does not align with the blue/green strategy requiring post-deployment tests.
Invoking a Lambda function to run tests in a stage before the deploy stage does not align with testing the green version after deployment. Like option A, this option fails to adhere to the blue/green deployment model which requires testing the application in the green environment after it has been deployed but before traffic is fully shifted.
Using a hooks section in the CodeDeploy AppSpec file to invoke a Lambda function after allowing test traffic ensures that the green version is tested post-deployment. If the tests fail, exiting the Lambda function with an error triggers a rollback, meeting all specified requirements for testing and rollback in the deployment process.
Although this option proposes using a hooks section in the AppSpec file, testing during the AfterAllowTraffic lifecycle event is not appropriate for the requirement. This event occurs after traffic has already been shifted to the green version, making it impossible to roll back if issues are found after that point. The testing should occur during the AfterAllowTestTraffic event instead.
From my perspective, the answer is:
Add a hooks section to the CodeDeploy AppSpec file. Use the AfterAllowTestTraffic lifecycle event to invoke an AWS Lambda function to run the test scripts. If errors are found, exit the Lambda function with an error to initiate rollback.