Correct Answer -B, E.
During AWS CodeDeploy automatic roll-back, it will try to retrieve files that were part of previous versions.
If these files are deleted or missing, you need to manually add those files to Instance or create a new application revision.
Option A is incorrect as if files required for deployment are overwritten by earlier deployment.
Files will not be available for CodeDeploy & deployment will fail even in case of Manual roll-back.
Option C is incorrect as AWS CodeDeploy will not find missing files using an existing application revision.
Option D is incorrect as CodeDeploy does not automatically access these files from S3 buckets.
For more information on CodeDeploy Rollback, refer to the following URL-
https://docs.aws.amazon.com/codedeploy/latest/userguide/deployments-rollback-and-redeploy.html
AWS CodeDeploy is a fully-managed deployment service that automates software deployments to various computing services such as Amazon EC2 instances, AWS Fargate, AWS Lambda, and on-premises servers. It simplifies the deployment process by automating the deployment process and reducing the deployment time. One of the key features of AWS CodeDeploy is the ability to roll-back to the last known good revision in case of deployment failures.
However, during the roll-back process, files required for deployment to the earlier revision cannot be retrieved by AWS CodeDeploy. To perform a successful roll-back, you need to perform one of the following actions:
Use Manual Roll-Back instead of Automatic Roll-Back: AWS CodeDeploy provides two types of roll-back mechanisms: Automatic and Manual. By default, the roll-back process is set to Automatic. In this case, AWS CodeDeploy automatically rolls back to the last known good revision when a deployment failure occurs. If files required for deployment to an earlier revision are missing, you can switch to Manual Roll-Back. In this case, you need to manually select the revision to which you want to roll back. Manual Roll-Back provides more control over the roll-back process, and you can choose the revision that has all the required files.
Create a new application revision: If you cannot retrieve the required files from the previous revision, you can create a new application revision that contains all the required files. You can use the AWS CodeDeploy CLI, API, or Console to create a new revision. Once you have created a new revision, you can deploy it to your instances. This ensures that all the required files are available during the deployment process.
In conclusion, if files required for deployment to an earlier revision are missing, you can switch to Manual Roll-Back or create a new application revision that contains all the required files.
