Lambda Web Gateway

A high-performance web gateway for AWS Lambda functions, written in Rust.

Features

• Seamless integration with AWS Lambda functions
• Support for both buffered and streaming Lambda invocations
• Configurable authentication (Open or API Key)
• Request transformation from HTTP to Lambda-compatible format
• Automatic handling of base64 encoding/decoding for request/response bodies
• Built with Rust and Axum for high performance and reliability
• Health check endpoint for monitoring
• Flexible configuration via YAML file or environment variables

Prerequisites

• Rust (latest stable version)
• AWS account and credentials configured
• AWS Lambda function(s) to be exposed via the gateway

Configuration

The gateway can be configured using a YAML file (config.yaml) or environment variables. Configuration options include:

• Lambda function name (required)
• Lambda invoke mode (Buffered or ResponseStream, default: Buffered)
• API keys (for API Key authentication mode)
• Authorization mode (Open or ApiKey, default: Open)
• Bind address (default: "0.0.0.0:8000")

Example config.yaml:

lambda_function_name: "my-lambda-function"
lambda_invoke_mode: "ResponseStream"
auth_mode: "ApiKey"
api_keys:
  - "key1"
  - "key2"
addr: "0.0.0.0:8000"

Alternatively, you can use environment variables:

• LAMBDA_FUNCTION_NAME
• LAMBDA_INVOKE_MODE
• API_KEYS (comma-separated list)
• AUTH_MODE (default: Open)
• ADDR

Environment variables take precedence over the configuration file when both are present.

Building and Running

1. Clone the repository:

   git clone https://github.com/aws-samples/aws-lambda-web-gateway.git
   cd aws-lambda-web-gateway
   

2. Build the project:

   cargo build --release
   

3. Create a config.yaml file in the project root or set the necessary environment variables.

4. Run the gateway:

   ./target/release/lambda-web-gateway
   

Usage

Once running, the gateway listens for HTTP requests on the configured address (default: 0.0.0.0:8000). All requests (except /healthz) are forwarded to the configured Lambda function.

• Health check: GET /healthz
• Lambda invocation: Any method on / or /*path

For API Key authentication, include the key in the x-api-key header or as a Bearer token in the Authorization header.

Performance Considerations

• The gateway is optimized for high throughput and low latency.
• Streaming responses are supported for improved performance with large payloads.
• The use of Rust and Axum ensures efficient resource utilization.

Development

To contribute to the project:

1. Fork the repository
2. Create a new branch for your feature
3. Implement your changes
4. Write tests for your new functionality
5. Submit a pull request

Please refer to CONTRIBUTING.md for more details on the contribution process.

Security

See CONTRIBUTING.md for more information on reporting security issues.

License

This project is licensed under the MIT-0 License. See the LICENSE file for details.