You are working on a Jenkins continuous delivery pipeline for a Golang project. The pipeline uses AWS CodeBuild to build the Docker image and push it to an AWS ECR repository. You already have the Dockerfile, and now you need to create the buildspec.yml file for the CodeBuild project. The buildspec.yml file has several stages, including install, pre_build, build and post_build. Before the build stage, you should have already logged in to ECR. Which commands are suitable to be placed in the CodeBuild build stage?

Answer options:

A.build:
commands: 
- $(aws ecr get-login --no-include-email --region $AWS_DEFAULT_REGION)
- docker build -t $IMAGE_REPO_NAME:$IMAGE_TAG .
- docker tag $IMAGE_REPO_NAME:$IMAGE_TAG 
- docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/ $IMAGE_REPO_NAME:$IMAGE_TAG
B. build:
commands: 
- $(aws ecr get-login --no-include-email --region $AWS_DEFAULT_REGION)
- docker build -t $IMAGE_REPO_NAME:$IMAGE_TAG .
- docker tag $IMAGE_REPO_NAME:$IMAGE_TAG 
- docker run $REPOSITORY_URI:$IMAGE_TAG
- docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/ $IMAGE_REPO_NAME:$IMAGE_TAG
C.build:
commands: 
- docker build -t $IMAGE_REPO_NAME:$IMAGE_TAG .
- docker tag $IMAGE_REPO_NAME:$IMAGE_TAG $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
- docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/ $IMAGE_REPO_NAME:$IMAGE_TAG
D. build:
commands: 
- docker start $IMAGE_REPO_NAME:$IMAGE_TAG 
- docker build -t $IMAGE_REPO_NAME:$IMAGE_TAG .
- docker tag $IMAGE_REPO_NAME:$IMAGE_TAG 
- docker run $IMAGE_REPO_NAME:$IMAGE_TAG 
- docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/ $IMAGE_REPO_NAME:$IMAGE_TAG
 

Correct Answer – C
Option A is incorrect: Because ECR login (aws ecr get-login) should be put in the pre_build phase. Option C is better than this option.
Option B is incorrect: Because the docker run should not be placed in the build phase. CodeBuild is used to build an artifact, and it is not suitable to run the Docker here.
Option C is CORRECT: Because in the build phase, the Docker image should be built and tagged. Then the Docker image should be pushed to ECR.
Option D is incorrect: Because docker start and docker run are inappropriate in the CodeBuild build phase. When building a Docker image, you do not need to run a Docker container.
The buildspec.yml file has several phases such as install, pre_build, build, and post_build. Check https://docs.aws.amazon.com/codebuild/latest/userguide/sample-docker.html for how to use CodeBuild to work with Docker image and ECR.