AWS Certified Developer - Associate (DVA-C02) Practice Exam

Correct Answer: C. Use AWS Secrets Manager with an AWS Key Management Service (AWS KMS) customer managed key to store the access token. Add a resource-based policy to the secret to allow access from other accounts. Update the IAM role of the EC2 instances with permissions to access Secrets Manager. Retrieve the token from Secrets Manager. Use the decrypted access token to send the message to the chat.

AWS Secrets Manager is the ideal solution for storing sensitive credentials like API access tokens. It provides automatic encryption at rest and in transit, supports resource-based policies for cross-account access, and handles decryption automatically when retrieving secrets. While Parameter Store SecureString can also store encrypted values, Secrets Manager is specifically designed for credential management and offers built-in rotation capabilities. The other options (DynamoDB and S3) require more manual setup for encryption and decryption, resulting in higher management overhead.

Correct Answer: D. Configure the permissions on the main account event bus to receive events from all accounts. Create an Amazon EventBridge rule in each account to send all the EC2 instance lifecycle events to the main account event bus. Add an EventBridge rule to the main account event bus that matches all EC2 instance lifecycle events. Set the SQS queue as a target for the rule.

Option D is correct because it follows the proper cross-account EventBridge pattern. First, you configure the main account's event bus to accept events from other accounts. Then, each source account creates a rule to forward EC2 lifecycle events to the main account's event bus. Finally, a rule in the main account routes these events to the SQS queue. Option B is incorrect because EventBridge rules cannot directly target cross-account SQS queues. Option A is incorrect because EC2 cannot be configured to directly deliver events to another account's event bus. Option C is inefficient and not event-driven.