How can this be accomplished?
Create and deploy nested AWS CloudFormation stacks with the parent stack consisting of the AWS CloudFront distribution and API Gateway, and the child stack containing the Lambda function. For changes to Lambda, create an AWS CloudFormation change set and deploy; if errors are triggered, revert the AWS CloudFormation change set to the previous version.
Use AWS SAM and built-in AWS CodeDeploy to deploy the new Lambda version, gradually shift traffic to the new version, and use pre-traffic and post-traffic test functions to verify code. Rollback if Amazon CloudWatch alarms are triggered.
Refactor the AWS CLI scripts into a single script that deploys the new Lambda version. When deployment is completed, the script tests execute. If errors are detected, revert to the previous Lambda version.
Create and deploy an AWS CloudFormation stack that consists of a new API Gateway endpoint that references the new Lambda version. Change the CloudFront origin to the new API Gateway endpoint, monitor errors and if detected, change the AWS CloudFront origin to the previous API Gateway endpoint.
Explanations:
While using AWS CloudFormation can manage deployments and rollbacks, creating nested stacks may complicate the process. AWS CloudFormation change sets do allow for reviewing changes before applying them, but the reverting process is not as automated or straightforward as needed for rapid deployment and rollback in serverless applications.
AWS SAM (Serverless Application Model) with AWS CodeDeploy provides a robust deployment strategy, including traffic shifting and testing mechanisms. This approach allows for gradual rollout of new Lambda versions and facilitates automatic rollback if errors are detected through CloudWatch alarms, thus reducing deployment time and improving error detection.
Refactoring the CLI scripts into a single script simplifies the process but does not inherently provide rollback capabilities or error detection mechanisms. If errors are detected post-deployment, reverting would still be a manual process, making this option less efficient than others in terms of speed and reliability.
This approach involves creating a new API Gateway endpoint for the Lambda function and changing the CloudFront origin. While it offers a way to manage Lambda versions, the process of reverting the API Gateway endpoint if errors occur adds complexity and delay to the rollback process, which contradicts the goal of reducing deployment and error detection times.
As I understand it, the answer is:
Use AWS SAM and built-in AWS CodeDeploy to deploy the new Lambda version, gradually shift traffic to the new version, and use pre-traffic and post-traffic test functions to verify code. Rollback if Amazon CloudWatch alarms are triggered.