What should the solutions architect do to resolve the error?
Change the CORS configuration on the S3 bucket. Add rules for CORS to the AllowedOrigin element for www.example.com.
Enable the CORS setting in AWS WAF. Create a web ACL rule in which the Access-Control-Allow-Origin header is set to www.example.com.
Enable the CORS setting on the API Gateway API endpoint. Ensure that the API endpoint is configured to return all responses that have the Access-Control-Allow-Origin header set to www.example.com.
Enable the CORS setting on the Lambda function. Ensure that the return code of the function has the Access-Control-Allow-Origin header set to www.example.com.
Explanations:
Changing the CORS configuration on the S3 bucket alone is not sufficient since the error is likely occurring at the API Gateway level, which also needs to be configured for CORS. The S3 bucket settings are not responsible for API Gateway responses.
AWS WAF does not handle CORS settings; it is used for filtering traffic and managing security rules. Enabling CORS in WAF is not applicable, as CORS is managed at the resource level (S3, API Gateway, etc.), not within WAF.
Enabling the CORS setting on the API Gateway API endpoint is the correct approach. It ensures that the API responds with the Access-Control-Allow-Origin header set towww.example.com, which is necessary for the frontend to communicate with the API without encountering CORS errors.
While Lambda functions can return headers, the correct approach is to configure the API Gateway to handle CORS. The API Gateway needs to be set up to manage CORS for the entire API, not just the Lambda function response.