Valid Integration Sources for API Gateway

Answer: A, B, D.

Option A is correct.

AWS API Gateway can integrate with any HTTP-based endpoints available over the internet.

Q: With what backends can Amazon API Gateway communicate?

Amazon API Gateway can execute AWS Lambda functions in your account, start AWS Step Functions state machines, or call HTTP endpoints hosted on AWS Elastic Beanstalk, Amazon EC2, and also non-AWS hosted HTTP based operations that are accessible via the public Internet.

API Gateway also allows you to specify a mapping template to generate static content to be returned, helping you mock your APIs before the backend is ready.

You can also integrate API Gateway with other AWS services directly.

For example, you could expose an API method in API Gateway that sends data directly to Amazon Kinesis.

Option B is correct.

AWS can use Lambda function from another account as an integration type.

Option C is incorrect.

AWS API gateway can connect to AWS services, making proxy calls only to their respective AWS APIs.

There is no integration type for database connections directly from API Gateway.

You can use the Lambda function to connect with the database and make Lambda as an integration type for API Gateway.

Option D is correct.

AWS has introduced VPC Link, a way to connect to the resources within a private VPC.Refer to the documentation here for more information on VPC Links.

https://aws.amazon.com/blogs/compute/introducing-amazon-api-gateway-private-endpoints/

API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale. Integration sources for API Gateway determine where the backend service resides, and how requests should be processed.

The valid integration sources for API Gateway are:

A. Public facing HTTP-based endpoints outside AWS network. This option refers to integrating API Gateway with HTTP/HTTPS endpoints that are hosted outside the AWS network. It enables API Gateway to serve as a proxy between clients and the backend HTTP endpoints.

B. Lambda functions from another account. This option enables integration of API Gateway with Lambda functions that are hosted in another AWS account. It is useful when multiple teams or organizations need to collaborate on building and deploying serverless applications.

D. VPC Link This option enables integration of API Gateway with resources that are hosted inside a Virtual Private Cloud (VPC). It provides a secure and private connection between the API Gateway and VPC resources, without exposing them to the public internet.

Note: Only a private endpoint can be used to connect a VPC with API Gateway.

Therefore, options A, B, and D are valid integration sources for API Gateway.

C. Database connections on the internet outside AWS network This option is not a valid integration source for API Gateway. Instead, the best practice is to use AWS services such as Amazon RDS, Amazon DynamoDB, or Amazon Aurora, which are highly available, scalable, and secure.

E. SFTP connection This option is also not a valid integration source for API Gateway. Instead, AWS provides services such as AWS Transfer Family, which is a fully managed service that enables the transfer of files over Secure File Transfer Protocol (SFTP), FTPS, and FTP.