Serverless on AWS GovCloud — Is your API gateway available?
Transitioning to a serverless architecture brings numerous advantages, but when deploying resources on AWS GovCloud, developers encounter unique considerations. Unlike commercial accounts, AWS GovCloud operates with certain limitations, particularly when it comes to API gateways. In this article, we’ll explore the three types of API gateway endpoints available in a standard commercial account and discuss how they differ in AWS GovCloud. We’ll also delve into the importance of leveraging private endpoints and resource policies to ensure a secure and controlled environment.
Understanding API Gateway Endpoints in a Commercial Account:
In a typical commercial account, AWS offers three types of API gateway endpoints: regional, edge-optimized, and private. These endpoints cater to different scenarios based on geographical distribution, latency optimization, and enhanced security.
The regional endpoint exposes an API within a specific AWS region. Clients within the same region can directly access the API Gateway deployment. However, clients outside the region must specifically target the regional endpoint to connect to the API.
The edge-optimized endpoint utilizes the global network of AWS Edge Locations and leverages the AWS CloudFront content delivery network (CDN). It routes requests to the nearest Edge Location and then directs them to the closest regional API Gateway deployment. This setup minimizes latency and proves beneficial when catering to a globally distributed client base.
The private endpoint allows for private access to an API within an Amazon Virtual Private Cloud (VPC). Integrating the API with other resources in the VPC, such as EC2 instances or Lambda functions, ensures a secure environment without exposing the API to the public internet. This endpoint type provides an additional layer of security and is useful for restricting API access to resources within the VPC or connected networks.
API Gateway Endpoints in AWS GovCloud
In AWS GovCloud, the available capabilities are intentionally limited to maintain the highest level of security. Consequently, the default endpoint configuration differs from that of a commercial account. In GovCloud, the default API gateway endpoint configuration is regional. This means that the API is only accessible within the specific AWS region where the API Gateway is deployed. The intention is to enforce a more secure application environment.
Leveraging Private Endpoints in GovCloud
To maintain a secure serverless application in GovCloud, it is recommended to utilize private endpoints for your API Gateway. By explicitly configuring the endpoint type as private, you restrict access to the API to resources within your VPC or connected networks.
To connect to and invoke functions within a private endpoint, a VPC endpoint must be created. This endpoint allows resources within the same VPC to reach the API Gateway securely. In your provider configurations, specify a list of VPC Endpoint IDs to establish this connection.
Resource Policies for Private API Gateways
Creating a resource policy is crucial for every private API gateway in GovCloud. This policy defines the permissions for accessing the resources connected to the API gateway. Without setting up the resource policy correctly, attempting to invoke functions will result in a “forbidden” message, denying access to the API.
Navigating API gateway endpoints in AWS GovCloud requires a nuanced understanding of the limitations and security considerations specific to this environment. By leveraging private endpoints, creating VPC endpoints, and configuring resource policies, developers can maintain a secure serverless application in GovCloud. Although the endpoint configurations differ from a standard commercial account, the proper implementation ensures controlled access to resources while adhering to stringent security requirements.