What is the MOST operationally efficient way to meet this requirement?
Create an AWS Lambda function that periodically checks the public access settings for each S3 bucket. Set up Amazon Simple Notification Service (Amazon SNS) to send notifications.
Create a cron script that uses the S3 API to check the public access settings for each S3 bucket. Set up Amazon Simple Notification Service (Amazon SNS) to send notifications.
Enable S3 Event Notifications for each S3 bucket. Subscribe S3 Event Notifications to an Amazon Simple Notification Service (Amazon SNS) topic.
Enable the s3-bucket-public-read-prohibited managed rule in AWS Config. Subscribe the AWS Config rule to an Amazon Simple Notification Service (Amazon SNS) topic.
Explanations:
Using a Lambda function to periodically check the public access settings is operationally inefficient because it introduces unnecessary complexity and overhead. It requires frequent checks and custom code, which is not the most optimal approach for real-time monitoring of public access changes.
A cron script that checks the public access settings is similarly inefficient because it involves custom management of cron jobs and API calls. This introduces manual overhead and doesn’t provide an automatic and consistent method for detecting changes in public access settings.
S3 Event Notifications are useful for triggering actions based on object-level events but are not suitable for monitoring changes to bucket-level configurations, such as public access settings. Therefore, this option won’t notify on changes to bucket permissions.
Enabling the s3-bucket-public-read-prohibited managed rule in AWS Config is the most operationally efficient solution. AWS Config continuously monitors S3 bucket settings and will automatically trigger notifications when a bucket becomes publicly readable. This solution is automated, scalable, and uses native AWS services.
I evaluate that the answer is:
Enable the s3-bucket-public-read-prohibited managed rule in AWS Config. Subscribe the AWS Config rule to an Amazon Simple Notification Service (Amazon SNS) topic.