actix-web/actix-http/examples/echo2.rs

use std::io;

use actix_http::{
    body::MessageBody, header::HeaderValue, Error, HttpService, Request, Response, StatusCode,
};
use actix_server::Server;
use bytes::BytesMut;
use futures_util::StreamExt as _;

async fn handle_request(mut req: Request) -> Result<Response<impl MessageBody>, Error> {
    let mut body = BytesMut::new();
    while let Some(item) = req.payload().next().await {
        body.extend_from_slice(&item?)
    }

    log::info!("request body: {:?}", body);

    Ok(Response::build(StatusCode::OK)
        .insert_header(("x-head", HeaderValue::from_static("dummy value!")))
        .body(body))
}

#[actix_rt::main]
async fn main() -> io::Result<()> {
    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));

    Server::build()
        .bind("echo", ("127.0.0.1", 8080), || {
            HttpService::build().finish(handle_request).tcp()
        })?
        .run()
        .await
}