docs: Fix tracing grpc example (#2710)

Author: cijothomas

examples/tracing-grpc/Cargo.toml

@@ -19,7 +19,7 @@ opentelemetry_sdk = { path = "../../opentelemetry-sdk", features = ["rt-tokio"]
 opentelemetry-stdout = { workspace = true, features = ["trace"] }
 prost = { workspace = true }
 tokio = { workspace = true, features = ["full"] }
-tonic = { workspace = true, features = ["server"] }
+tonic = { workspace = true, features = ["server", "codegen", "channel", "prost"] }
 
 [build-dependencies]
 tonic-build = { workspace = true }

examples/tracing-grpc/src/client.rs

@@ -13,7 +13,7 @@ fn init_tracer() -> sdktrace::SdkTracerProvider {
     global::set_text_map_propagator(TraceContextPropagator::new());
     // Install stdout exporter pipeline to be able to retrieve the collected spans.
     let provider = sdktrace::SdkTracerProvider::builder()
-        .with_batch_exporter(SpanExporter::default())
+        .with_simple_exporter(SpanExporter::default())
         .build();
 
     global::set_tracer_provider(provider.clone());
@@ -43,10 +43,14 @@ async fn greet() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static
     let span = tracer
         .span_builder("Greeter/client")
         .with_kind(SpanKind::Client)
-        .with_attributes([KeyValue::new("component", "grpc")])
+        .with_attributes([
+            KeyValue::new("rpc.system", "grpc"),
+            KeyValue::new("server.port", 50052),
+            KeyValue::new("rpc.method", "say_hello"),
+        ])
         .start(&tracer);
     let cx = Context::current_with_span(span);
-    let mut client = GreeterClient::connect("http://[::1]:50051").await?;
+    let mut client = GreeterClient::connect("http://[::1]:50052").await?;
 
     let mut request = tonic::Request::new(HelloRequest {
         name: "Tonic".into(),
@@ -58,16 +62,23 @@ async fn greet() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static
 
     let response = client.say_hello(request).await;
 
+    let span = cx.span();
     let status = match response {
-        Ok(_res) => "OK".to_string(),
+        Ok(_res) => {
+            span.set_attribute(KeyValue::new("response", "OK"));
+            "OK".to_string()
+        }
         Err(status) => {
             // Access the status code
             let status_code = status.code();
+            span.set_attribute(KeyValue::new(
+                "response_code_desc",
+                status_code.description(),
+            ));
             status_code.to_string()
         }
     };
-    cx.span()
-        .add_event("Got response!", vec![KeyValue::new("status", status)]);
+    span.add_event("Got response!", vec![KeyValue::new("status", status)]);
 
     Ok(())
 }

examples/tracing-grpc/src/server.rs

@@ -1,5 +1,6 @@
 use hello_world::greeter_server::{Greeter, GreeterServer};
 use hello_world::{HelloReply, HelloRequest};
+use opentelemetry::KeyValue;
 use opentelemetry::{
     global,
     propagation::Extractor,
@@ -13,7 +14,7 @@ fn init_tracer() -> SdkTracerProvider {
     global::set_text_map_propagator(TraceContextPropagator::new());
     // Install stdout exporter pipeline to be able to retrieve the collected spans.
     let provider = SdkTracerProvider::builder()
-        .with_batch_exporter(SpanExporter::default())
+        .with_simple_exporter(SpanExporter::default())
         .build();
 
     global::set_tracer_provider(provider.clone());
@@ -65,6 +66,11 @@ impl Greeter for MyGreeter {
         let mut span = tracer
             .span_builder("Greeter/server")
             .with_kind(SpanKind::Server)
+            .with_attributes([
+                KeyValue::new("rpc.system", "grpc"),
+                KeyValue::new("server.port", 50052),
+                KeyValue::new("rpc.method", "say_hello"),
+            ])
             .start_with_context(&tracer, &parent_cx);
 
         let name = request.into_inner().name;
@@ -83,7 +89,7 @@ impl Greeter for MyGreeter {
 async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
     let provider = init_tracer();
 
-    let addr = "[::1]:50051".parse()?;
+    let addr = "[::1]:50052".parse()?;
     let greeter = MyGreeter::default();
 
     Server::builder()