A developer asks you to help on setting up AWS CodeBuild for a new Java project. The project is built by Maven. In its buildspec.yml file,there are several phases such as install, pre_build and build. There is a requirement that if a command in a phase has failed, CodeBuild still has a chance to run some shell commands to do custom operations such as log collection. How should you configure the CodeBuild project to meet the need?

Answer options:

A.Put the custom operation commands in the post_build phase so that they can still run when the build fails.
B.Add a finally block after the commands block in each phase. Put the custom shell commands in the finally block.
C.Create a CloudWatch Events rule for any CodeBuild failure event. Add a Lambda Function as the target to do custom operations.
D.Trigger an SNS notification if a build fails in the CodeBuild project. Use a Lambda Function to subscribe to the SNS topic and handle the required custom operations.

Correct Answer – B
To deal with the situation mentioned in the question, the buildspec.yml file has provided the optional finally block to execute commands even if a command in the commands block fails. The reference is in
https://docs.aws.amazon.com/codebuild/latest/userguide/build-spec-ref.html.
Option A is incorrect: The post_build phase can run if the build phase fails. However, if the install or pre-build phase fails, the project is finalized without the post_build phase being executed.
Option B is CORRECT: For example:
 install:
commands:
- apt-get install -y maven
finally:
- echo The shell commands here always run even if the above command fails
Option C is incorrect: Because the rule is created for any CodeBuild project failure. That means other projects may trigger this CloudWatch Event rule as well.
Option D is incorrect: Because this is not a straightforward approach since the buildspec.yml file already provides a block to execute the required commands.