feat(transport): Add tracing support to server (#175)

* feat(transport): Add tracing to server

* Add tracing example

* Fix duplicate versions of tracing-subscriber

tonic-examples/Cargo.toml

@@ -66,6 +66,14 @@ path = "src/multiplex/client.rs"
 name = "gcp-client"
 path = "src/gcp/client.rs"
 
+[[bin]]
+name = "tracing-client"
+path = "src/tracing/client.rs"
+
+[[bin]]
+name = "tracing-server"
+path = "src/tracing/server.rs"
+
 [dependencies]
 tonic = { path = "../tonic", features = ["tls"] }
 bytes = "0.4"
@@ -82,6 +90,12 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 rand = "0.6"
 
+# Tracing
+tracing = "0.1"
+tracing-subscriber =  { version = "0.2.0-alpha", features = ["tracing-log"] }
+tracing-attributes = "0.1"
+tracing-futures = "0.2"
+
 # Required for wellknown types
 prost-types = "0.5"
 

tonic-examples/src/tracing/client.rs

@@ -0,0 +1,38 @@
+pub mod hello_world {
+    tonic::include_proto!("helloworld");
+}
+
+use hello_world::{greeter_client::GreeterClient, HelloRequest};
+use tracing_attributes::instrument;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tracing_subscriber::FmtSubscriber::builder()
+        .with_max_level(tracing::Level::DEBUG)
+        .init();
+
+    say_hi("Bob".into()).await?;
+
+    Ok(())
+}
+
+#[instrument]
+async fn say_hi(name: String) -> Result<(), Box<dyn std::error::Error>> {
+    let mut client = GreeterClient::connect("http://[::1]:50051").await?;
+
+    let request = tonic::Request::new(HelloRequest { name });
+
+    tracing::info!(
+        message = "Sending request.",
+        request = %request.get_ref().name
+    );
+
+    let response = client.say_hello(request).await?;
+
+    tracing::info!(
+        message = "Got a response.",
+        response = %response.get_ref().message
+    );
+
+    Ok(())
+}

tonic-examples/src/tracing/server.rs

@@ -0,0 +1,51 @@
+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> {
+        tracing::info!(message = "Inbound request.", metadata = ?request.metadata());
+
+        let reply = hello_world::HelloReply {
+            message: format!("Hello {}!", request.into_inner().name).into(),
+        };
+
+        tracing::debug!(message = "Sending reply.", response = %reply.message);
+
+        Ok(Response::new(reply))
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tracing_subscriber::FmtSubscriber::builder()
+        .with_max_level(tracing::Level::DEBUG)
+        .init();
+
+    let addr = "[::1]:50051".parse().unwrap();
+    let greeter = MyGreeter::default();
+
+    tracing::info!(message = "Starting server.", %addr);
+
+    Server::builder()
+        .trace_fn(|_| tracing::info_span!("helloworld_server"))
+        .add_service(GreeterServer::new(greeter))
+        .serve(addr)
+        .await?;
+
+    Ok(())
+}