How to: map hyper::Body to lambda_http::Body

[metasim]

I'm trying to create some impedance-matching glue between lambda_http and axum, so I can use the Route construct. I'm doing this via a Service trait, transforming an axum::http::Response into a lambda_http::Response. The place where I'm stuck is transforming the hyper::Body (an opaque struct that behaves as a stream), into the lambda_http::Body, an Enum with owned content.

I've tried using hyper::body::to_bytes, but the Response from axum doesn't fulfill the HttpBody type bound.

I'm fairly new to Rust, so I may be "using it wrong", or trying to do something that should be done some other way. Basically would like to use lambda_http with axum.

[metasim]

I think I cracked the nut (but welcome feedback if there's a better way!):

use lambda_http as LH;
use axum::http as AH;
use axum::body::BoxBody;
use hyper::body::to_bytes;

async fn lambda_http_response_from_axum(resp: AH::Response<BoxBody>) -> Result<LH::Response<LH::Body>, LH::Error> {
    let (head, body) = resp.into_parts();
    let raw = to_bytes(body).await?;
    let resp = LH::Response::from_parts(head, LH::Body::Binary(raw.to_vec()));
    Ok(resp)
}

Still need to properly handle content type....

[bnusunny]

I did similar conversion in Lambda Adapter. It converts reqwest::Response to lambda_http::Body. It handles binary data in the same way as Application Load Balancer. The code is here.

https://github.com/aws-samples/aws-lambda-adapter/blob/40b3b305f07e015de3b860ca23f01eb029a20337/src/main.rs#L90

[metasim]

Cool project @bnusunny! Thanks for the link!