Exam AWS Certified DevOps Engineer - Professional DOP-C02 topic 1 question 34 discussion

Add a hooks section to the CodeDeploy AppSpec file. The AppSpec file is a YAML file that describes how to deploy an application to Amazon ECS using CodeDeploy. We can use the AfterAllowTestTraffic lifecycle event to run the test scripts. This event is triggered after the new version of the application is deployed, and before traffic is shifted to the new version. In the AfterAllowTestTraffic lifecycle event, invoke an AWS Lambda function to run the test scripts. The Lambda function can be written in any programming language supported by Lambda, such as Python, Node.js, or Java. If the test scripts detect any errors, exit the Lambda function with an error code. This will cause the deployment to fail, and CodeDeploy will initiate a rollback.

AfterAllowTestTraffic lifecycle event in the hooks section will not shift the whole traffic to the green application but only a small percentage of traffic to the newly deployed version. C is the answer

CodeDeploy Blue/Green deployments, the AfterAllowTestTraffic hook is triggered after the test traffic redirection to the new version (Green) is set. Additional verification, testing, or other custom actions can be automated by executing Lambda functions at this time.

C is correct: we can initiate the script using lambda for advanced features A and B are wrong: Both trigger the test script befor deploy stages D is wrong: It only stops the deployment, not rollback it

C is right.

C is the right answer. https://docs.aws.amazon.com/codedeploy/latest/userguide/reference-appspec-file-structure-hooks.html#appspec-hooks-ecs

The correct solution to meet these requirements is option C. Explanation: In this scenario, the requirement is to add scripts to test the green version of the application before shifting traffic. These scripts should be executed quickly and, in case of errors, the application must be rolled back. To achieve this, we can use the following steps:

Lifecycle event hooks for an Amazon ECS deployment: AfterAllowTraffic – Use to run tasks after the second target group serves traffic to the replacement task set. The results of a hook function at this lifecycle event can trigger a rollback.

C is the correct answer