client.rs

#![deny(warnings, rust_2018_idioms)]

use futures::Future;
use hyper::client::connect::{Destination, HttpConnector};
use tower_grpc::Request;
use tower_hyper::{client, util};
use tower_util::MakeService;

use std::error::Error;

pub mod hello_world {
    include!(concat!(env!("OUT_DIR"), "/helloworld.rs"));
}

//What is the correct return type here?
fn make_client(uri: http::Uri) -> Result<Box<dyn Future<Item=hello_world::client::Greeter<Box<dyn tower_grpc::codegen::client::grpc::GrpcService<(), ResponseBody=(), Future=(), Error=()>>>, Error=tower_grpc::Status> + Send>, Box<dyn Error>> {
    let dst = Destination::try_from_uri(uri.clone())?;
    let connector = util::Connector::new(HttpConnector::new(4));
    let settings = client::Builder::new().http2_only(true).clone();
    let mut make_client = client::Connect::with_builder(connector, settings);

    let say_hello = make_client
        .make_service(dst)
        .map_err(|e| panic!("connect error: {:?}", e))
        .and_then(move |conn| {
            use crate::hello_world::client::Greeter;

            let conn = tower_request_modifier::Builder::new()
                .set_origin(uri)
                .build(conn)
                .unwrap();

            // Wait until the client is ready...
            Greeter::new(Box::new(conn)).ready()
        });
    Ok(Box::new(say_hello))
}

pub fn main() -> Result<(), Box<dyn Error>> {
    let _ = ::env_logger::init();

    let uri: http::Uri = format!("http://[::1]:50051").parse()?;

    let say_hello = make_client(uri)?
        .and_then(|mut client| {
            use crate::hello_world::HelloRequest;

            client.say_hello(Request::new(HelloRequest {
                name: "What is in a name?".to_string(),
            }))
        })
        .and_then(|response| {
            println!("RESPONSE = {:?}", response);
            Ok(())
        })
        .map_err(|e| {
            println!("ERR = {:?}", e);
        });

    tokio::run(say_hello);
    Ok(())
}

//   Compiling tower-grpc-examples v0.1.0 (C:\Users\ipc\CLionProjects\tower-grpc\tower-grpc-examples)
// error[E0271]: type mismatch resolving `<futures::future::and_then::AndThen<futures::future::map_err::MapErr<tower_hyper::client::connect::ConnectFuture<hyper::client::connect::Destination, _, tower_hyper::util::Connector<hyper::client::connect::http::HttpConnector>, tokio_executor::global::DefaultExecutor>, [closure@tower-grpc-examples\src/helloworld/client.rs:23:18: 23:54]>, impl futures::future::Future, [closure@tower-grpc-examples\src/helloworld/client.rs:24:19: 34:10 uri:_]> as futures::future::Future>::Item == hello_world::client::Greeter<std::boxed::Box<dyn tower_grpc::generic::client::GrpcService<(), Error = (), Future = (), ResponseBody = ()>>>`
//   --> tower-grpc-examples\src/helloworld/client.rs:35:8
//   |
// 35 |     Ok(Box::new(say_hello))
//   |        ^^^^^^^^^^^^^^^^^^^ expected struct `tower_request_modifier::RequestModifier`, found trait tower_grpc::generic::client::GrpcService
//   |
//   = note: expected type `hello_world::client::Greeter<std::boxed::Box<tower_request_modifier::RequestModifier<tower_hyper::client::connection::Connection<_>, _>>>`
//               found type `hello_world::client::Greeter<std::boxed::Box<dyn tower_grpc::generic::client::GrpcService<(), Error = (), Future = (), ResponseBody = ()>>>`
//   = note: required for the cast to the object type `dyn futures::future::Future<Error = tower_grpc::status::Status, Item = hello_world::client::Greeter<std::boxed::Box<dyn tower_grpc::generic::client::GrpcService<(), Error = (), Future = (), ResponseBody = ()>>>> + std::marker::Send`

// error[E0599]: no method named `say_hello` found for type `hello_world::client::Greeter<std::boxed::Box<dyn tower_grpc::generic::client::GrpcService<(), Error = (), Future = (), ResponseBody = ()>>>` in the current scope
//   --> tower-grpc-examples\src/helloworld/client.rs:47:20
//   |
// 47 |             client.say_hello(Request::new(HelloRequest {
//   |                    ^^^^^^^^^
//   |
//   ::: C:\Users\icooke\CLionProjects\tower-grpc\target\debug\build\tower-grpc-examples-7f408b4977dc8e0d\out/helloworld.rs:19:5
//   |
// 19 |     pub struct Greeter<T> {
//   |     --------------------- method `say_hello` not found for this
//   |
//   = help: items from traits can only be used if the trait is implemented and in scope
//   = note: the following trait defines an item `say_hello`, perhaps you need to implement it:
//           candidate #1: `hello_world::server::Greeter`

// error: aborting due to 2 previous errors

// Some errors have detailed explanations: E0271, E0599.
// For more information about an error, try `rustc --explain E0271`.
// error: Could not compile `tower-grpc-examples`.

// To learn more, run the command again with --verbose.