feat(transport): Allow custom IO and UDS example

examples/Cargo.toml

@@ -78,12 +78,20 @@ path = "src/tracing/client.rs"
 name = "tracing-server"
 path = "src/tracing/server.rs"
 
+[[bin]]
+name = "uds-client"
+path = "src/uds/client.rs"
+
+[[bin]]
+name = "uds-server"
+path = "src/uds/server.rs"
+
 [dependencies]
 tonic = { path = "../tonic", features = ["tls"] }
 bytes = "0.4"
 prost = "0.5"
 
-tokio = { version = "0.2", features = ["rt-threaded", "time", "stream", "fs", "macros"] }
+tokio = { version = "0.2", features = ["rt-threaded", "time", "stream", "fs", "macros", "uds"] }
 futures = { version = "0.3", default-features = false, features = ["alloc"]}
 async-stream = "0.2"
 http = "0.2"

examples/src/uds/client.rs

@@ -0,0 +1,39 @@
+#[cfg(unix)]
+
+pub mod hello_world {
+    tonic::include_proto!("helloworld");
+}
+
+use hello_world::{greeter_client::GreeterClient, HelloRequest};
+use http::Uri;
+use std::convert::TryFrom;
+use tokio::net::UnixStream;
+use tonic::transport::Endpoint;
+use tower::service_fn;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // We will ignore this uri because uds do not use it
+    // if your connector does use the uri it will be provided
+    // as the request to the `MakeConnection`.
+    let channel = Endpoint::try_from("lttp://[::]:50051")?
+        .connect_with_connector(service_fn(|_: Uri| {
+            let path = "/tmp/tonic/helloworld";
+
+            // Connect to a Uds socket
+            UnixStream::connect(path)
+        }))
+        .await?;
+
+    let mut client = GreeterClient::new(channel);
+
+    let request = tonic::Request::new(HelloRequest {
+        name: "Tonic".into(),
+    });
+
+    let response = client.say_hello(request).await?;
+
+    println!("RESPONSE={:?}", response);
+
+    Ok(())
+}

examples/src/uds/server.rs

@@ -0,0 +1,48 @@
+use std::path::Path;
+use tokio::net::UnixListener;
+use tonic::{transport::Server, Request, Response, Status};
+
+pub mod hello_world {
+    tonic::include_proto!("helloworld");
+}
+
+use hello_world::{
+    greeter_server::{Greeter, GreeterServer},
+    HelloReply, HelloRequest,
+};
+
+#[derive(Default)]
+pub struct MyGreeter {}
+
+#[tonic::async_trait]
+impl Greeter for MyGreeter {
+    async fn say_hello(
+        &self,
+        request: Request<HelloRequest>,
+    ) -> Result<Response<HelloReply>, Status> {
+        println!("Got a request: {:?}", request);
+
+        let reply = hello_world::HelloReply {
+            message: format!("Hello {}!", request.into_inner().name).into(),
+        };
+        Ok(Response::new(reply))
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let path = "/tmp/tonic/helloworld";
+
+    tokio::fs::create_dir_all(Path::new(path).parent().unwrap()).await?;
+
+    let mut uds = UnixListener::bind(path)?;
+
+    let greeter = MyGreeter::default();
+
+    Server::builder()
+        .add_service(GreeterServer::new(greeter))
+        .serve_with_incoming(uds.incoming())
+        .await?;
+
+    Ok(())
+}

tonic/src/transport/channel/endpoint.rs

@@ -1,3 +1,4 @@
+use super::super::service;
 use super::Channel;
 #[cfg(feature = "tls")]
 use super::ClientTlsConfig;
@@ -12,6 +13,7 @@ use std::{
     sync::Arc,
     time::Duration,
 };
+use tower_make::MakeConnection;
 
 /// Channel builder.
 ///
@@ -182,7 +184,35 @@ impl Endpoint {
 
     /// Create a channel from this config.
     pub async fn connect(&self) -> Result<Channel, Error> {
-        Channel::connect(self.clone()).await
+        let mut http = hyper::client::connect::HttpConnector::new();
+        http.enforce_http(false);
+        http.set_nodelay(self.tcp_nodelay);
+        http.set_keepalive(self.tcp_keepalive);
+
+        #[cfg(feature = "tls")]
+        let connector = service::connector(http, self.tls.clone());
+
+        #[cfg(not(feature = "tls"))]
+        let connector = service::connector(http);
+
+        Channel::connect(connector, self.clone()).await
+    }
+
+    /// Connect with a custom connector.
+    pub async fn connect_with_connector<C>(&self, connector: C) -> Result<Channel, Error>
+    where
+        C: MakeConnection<Uri> + Send + 'static,
+        C::Connection: Unpin + Send + 'static,
+        C::Future: Send + 'static,
+        crate::Error: From<C::Error> + Send + 'static,
+    {
+        #[cfg(feature = "tls")]
+        let connector = service::connector(connector, self.tls.clone());
+
+        #[cfg(not(feature = "tls"))]
+        let connector = service::connector(connector);
+
+        Channel::connect(connector, self.clone()).await
     }
 }
 

tonic/src/transport/channel/mod.rs

@@ -15,13 +15,15 @@ use http::{
     uri::{InvalidUri, Uri},
     Request, Response,
 };
+use hyper::client::connect::Connection as HyperConnection;
 use std::{
     fmt,
     future::Future,
     pin::Pin,
     sync::Arc,
     task::{Context, Poll},
 };
+use tokio::io::{AsyncRead, AsyncWrite};
 use tower::{
     buffer::{self, Buffer},
     discover::Discover,
@@ -121,11 +123,17 @@ impl Channel {
         Self::balance(discover, buffer_size, interceptor_headers)
     }
 
-    pub(crate) async fn connect(endpoint: Endpoint) -> Result<Self, super::Error> {
+    pub(crate) async fn connect<C>(connector: C, endpoint: Endpoint) -> Result<Self, super::Error>
+    where
+        C: Service<Uri> + Send + 'static,
+        C::Error: Into<crate::Error> + Send,
+        C::Future: Unpin + Send,
+        C::Response: AsyncRead + AsyncWrite + HyperConnection + Unpin + Send + 'static,
+    {
         let buffer_size = endpoint.buffer_size.clone().unwrap_or(DEFAULT_BUFFER_SIZE);
         let interceptor_headers = endpoint.interceptor_headers.clone();
 
-        let svc = Connection::new(endpoint)
+        let svc = Connection::new(connector, endpoint)
             .await
             .map_err(|e| super::Error::from_source(super::ErrorKind::Client, e))?;
 

tonic/src/transport/server/incoming.rs

@@ -0,0 +1,75 @@
+use super::Server;
+use crate::transport::service::BoxedIo;
+use futures_core::Stream;
+use futures_util::stream::TryStreamExt;
+use hyper::server::{
+    accept::Accept,
+    conn::{AddrIncoming, AddrStream},
+};
+use std::{
+    net::SocketAddr,
+    pin::Pin,
+    task::{Context, Poll},
+    time::Duration,
+};
+use tokio::io::{AsyncRead, AsyncWrite};
+#[cfg(feature = "tls")]
+use tracing::error;
+
+#[cfg_attr(not(feature = "tls"), allow(unused_variables))]
+pub(crate) fn tcp_incoming<IO, IE>(
+    incoming: impl Stream<Item = Result<IO, IE>>,
+    server: Server,
+) -> impl Stream<Item = Result<BoxedIo, crate::Error>>
+where
+    IO: AsyncRead + AsyncWrite + Unpin + Send + 'static,
+    IE: Into<crate::Error>,
+{
+    async_stream::try_stream! {
+        futures_util::pin_mut!(incoming);
+
+        while let Some(stream) = incoming.try_next().await? {
+            #[cfg(feature = "tls")]
+            {
+                if let Some(tls) = &server.tls {
+                    let io = match tls.accept(stream).await {
+                        Ok(io) => io,
+                        Err(error) => {
+                            error!(message = "Unable to accept incoming connection.", %error);
+                            continue
+                        },
+                    };
+                    yield BoxedIo::new(io);
+                    continue;
+                }
+            }
+
+            yield BoxedIo::new(stream);
+        }
+    }
+}
+
+pub(crate) struct TcpIncoming {
+    inner: AddrIncoming,
+}
+
+impl TcpIncoming {
+    pub(crate) fn new(
+        addr: SocketAddr,
+        nodelay: bool,
+        keepalive: Option<Duration>,
+    ) -> Result<Self, crate::Error> {
+        let mut inner = AddrIncoming::bind(&addr)?;
+        inner.set_nodelay(nodelay);
+        inner.set_keepalive(keepalive);
+        Ok(TcpIncoming { inner })
+    }
+}
+
+impl Stream for TcpIncoming {
+    type Item = Result<AddrStream, std::io::Error>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        Pin::new(&mut self.inner).poll_accept(cx)
+    }
+}