README.md

Fastly Http Client for the AWS Rust SDK

The aws-fastly-http-client crate allows you to use the AWS Rust SDK on Fastly Compute @ Edge. The crate contains an implementation of HttpClient you can plug into the AWS Rust SDK. We've only used this with the aws-sdk-dynamodb but it should work with other services as well.

Dependencies

We found that we needed to disable all default features of the AWS Rust SDK to make our project build for Fastly Compute@Edge. For example, if you're adding the aws-sdk-dynamodb crate, you'll need to add this to your Cargo.toml:

aws-sdk-dynamodb = { version = "1.9.0", default-features = false }

Additionally, we rely on Tokio for some of the async stuff, so you might want to add this to your Cargo.toml and use the tokio::main macro.

tokio = { version = "1.35.1", features = ["macros", "rt"] }

Usage

AWS's Rust SDK allows you to control a lot of stuff related to networking, but since Fastly handles that for us, most of the networking things can be disabled. Here's an example with a SdkConfig that worked for us:

#[tokio::main(flavor = "current_thread")]
async fn main() {
    let http_client = FastlyHttpClient::from("my_backend_name");
    let config = aws_sdk_dynamodb::Config::builder()
        .region(Some(Region::from_static("us-east-1")))
        .credentials_provider(credentials_provider())
        .retry_config(RetryConfig::disabled())
        .timeout_config(TimeoutConfig::disabled())
        .stalled_stream_protection(StalledStreamProtectionConfig::disabled())
        .identity_cache(IdentityCache::no_cache())
        .http_client(http_client)
        .behavior_version(BehaviorVersion::v2023_11_09())
        .build();

    let client = aws_sdk_dynamodb::Client::from_conf(config);

    let request = Request::from_client();
    let result = client
        .get_item()
        .table_name("paths")
        .key("path", AttributeValue::S(request.get_path().to_string()))
        .send()
        .await
        .unwrap();

    let response = match result.item {
        Some(_) => Response::from_status(StatusCode::OK),
        None => Response::from_status(StatusCode::NOT_FOUND),
    };

    response.send_to_client()
}