Review Mode Set 2 Qn 25

[xiaochris]

You are developing a marketplace app for emoji stickers hosted in Docker containers deployed on Amazon ECS. For each deployment, you need to verify that the set of core APIs are working before continuing to allow production traffic to flow on the new app version. If the API tests are unsuccessful, the deployment will automatically rollback to the older version. Your validation scripts are a set of functions on AWS Lambda which should run for each deployment.

How can you implement this verification effectively?

A) Define your Lambda functions in the AfterInstall lifecycle hook of the AppSpec.yaml file. Configure the Lambda functions to validate the deployment after installing the new version and rollback if the tests fail.

B) Define your Lambda functions in the AfterAllowTraffic lifecycle hook of the AppSpec.yaml file. Configure the Lambda functions to validate the deployment using production traffic and rollback if the tests fail.

C) Define your Lambda functions in the AfterAllowTestTraffic lifecycle hook of the AppSpec.yaml file. Configure the Lambda functions to validate the deployment using the test traffic and rollback if the tests fail.

D) Define your Lambda functions in the BeforeAllowTraffic lifecycle hook of the AppSpec.yaml file. Configure the Lambda functions to validate the deployment before allowing production traffic and rollback if the tests fail.

Why is C correct instead of D? C & D both looks like the correct answer since both is before allowing production traffic to come in.

Though C says “AfterAllowTestTraffic” which also could mean anytime after AfterAllowTestTraffic stage right?

• This discussion was modified 3 years, 10 months ago by  xiaochris.

[TutorialsDojo-Support]

Hello xiaochris,

Thank you for your feedback.

For this question, you want to run Lambda functions to validate your new deployment, even before production traffic flows to the. The recommended stage on where to run the validations is on the “AfterAllowTestTraffic” lifecycle hook. At this stage, the new deployment has its own “test listener” in which you can perform testing to validate that the application is working as expected.

With the “BeforeAllowTraffic” lifecycle hook, the validation on the “test listener” is completed and the new deployment in on its own target group. You use this stage when you know that the new deployment is successful and you need to perform extra actions before allowing the production traffic to it.

https://docs.aws.amazon.com/codedeploy/latest/userguide/reference-appspec-file-structure-hooks.html#reference-appspec-file-structure-hooks-run-order-ecs

Hope this helps.

Regards,

Kenneth Samonte @ Tutorials Dojo