Do a synchronous http client fetch within an actix thread

问题

I have an actix endpoint, and I need to do a synchronous http client fetch to get some results, and return some data. My endpoints cannot use async, so I can't use any .await methods.

I've tried using reqwests blocking client in my endpoint like so:

{ ...

  let res = reqwest::blocking::get(&fetch_url)?
    .json::<MyResp>()?;
  ...

But it gives me the error:

thread 'main' panicked at 'Cannot start a runtime from within a runtime. This happens because a function (like `block_on`) attempted to block the current thread while the thread is being used to drive asynchronous tasks.', /.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.9/src/runtime/enter.rs:19:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

回答1:

I couldn't figure out how to get it working with reqwest (it must have some weird conflicts with actix), but for some reason it worked fine with chttp.

chttp::get(&fetch_url)?.text()?;

回答2:

You cannot use blocking functions inside async functions.

Instead of reqwest::blocking::get() use reqwest::get().await.

回答3:

you should try creating a new thread for that:

std::thread::spawn(move || {

    reqwest::blocking::get(&url).unwrap().json().unwrap()

}).join().unwrap()

来源：https://stackoverflow.com/questions/60580769/do-a-synchronous-http-client-fetch-within-an-actix-thread