opentelemetry: remove tonic dependency (#414)

.github/workflows/ci.yml

@@ -52,7 +52,7 @@ jobs:
         override: true
     - name: Run tests
       run: cargo --version &&
-        cargo test --verbose --manifest-path=opentelemetry/Cargo.toml --features trace,metrics,serialize,tokio,serde,http,tonic,reqwest,testing &&
+        cargo test --verbose --manifest-path=opentelemetry/Cargo.toml --features trace,metrics,serialize,tokio,serde,http,reqwest,testing &&
         cargo test --manifest-path=opentelemetry-jaeger/Cargo.toml &&
         cargo test --manifest-path=opentelemetry-zipkin/Cargo.toml
   meta:

examples/grpc/Cargo.toml

@@ -16,7 +16,7 @@ http = "0.2"
 tonic = "0.3"
 prost = "0.6"
 tokio = { version = "0.2", features = ["full"] }
-opentelemetry = { path = "../../opentelemetry", features = ["tonic"] }
+opentelemetry = { path = "../../opentelemetry" }
 opentelemetry-jaeger = { path = "../../opentelemetry-jaeger" }
 
 [build-dependencies]

examples/grpc/src/client.rs

@@ -4,10 +4,24 @@ use opentelemetry::global;
 use opentelemetry::sdk::propagation::TraceContextPropagator;
 use opentelemetry::trace::TraceError;
 use opentelemetry::{
+    propagation::Injector,
     trace::{TraceContextExt, Tracer},
     Context, KeyValue,
 };
 
+struct MetadataMap<'a>(&'a mut tonic::metadata::MetadataMap);
+
+impl<'a> Injector for MetadataMap<'a> {
+    /// Set a key and value in the MetadataMap.  Does nothing if the key or value are not valid inputs
+    fn set(&mut self, key: &str, value: String) {
+        if let Ok(key) = tonic::metadata::MetadataKey::from_bytes(key.as_bytes()) {
+            if let Ok(val) = tonic::metadata::MetadataValue::from_str(&value) {
+                self.0.insert(key, val);
+            }
+        }
+    }
+}
+
 pub mod hello_world {
     tonic::include_proto!("helloworld");
 }
@@ -30,7 +44,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>
         name: "Tonic".into(),
     });
     global::get_text_map_propagator(|propagator| {
-        propagator.inject_context(&cx, request.metadata_mut())
+        propagator.inject_context(&cx, &mut MetadataMap(request.metadata_mut()))
     });
 
     let response = client.say_hello(request).await?;

examples/grpc/src/server.rs

@@ -6,6 +6,7 @@ use opentelemetry::global;
 use opentelemetry::sdk::propagation::TraceContextPropagator;
 use opentelemetry::trace::TraceError;
 use opentelemetry::{
+    propagation::Extractor,
     trace::{Span, Tracer},
     KeyValue,
 };
@@ -15,6 +16,26 @@ pub mod hello_world {
     tonic::include_proto!("helloworld"); // The string specified here must match the proto package name.
 }
 
+struct MetadataMap<'a>(&'a tonic::metadata::MetadataMap);
+
+impl<'a> Extractor for MetadataMap<'a> {
+    /// Get a value for a key from the MetadataMap.  If the value can't be converted to &str, returns None
+    fn get(&self, key: &str) -> Option<&str> {
+        self.0.get(key).and_then(|metadata| metadata.to_str().ok())
+    }
+
+    /// Collect all the keys from the MetadataMap.
+    fn keys(&self) -> Vec<&str> {
+        self.0
+            .keys()
+            .map(|key| match key {
+                tonic::metadata::KeyRef::Ascii(v) => v.as_str(),
+                tonic::metadata::KeyRef::Binary(v) => v.as_str(),
+            })
+            .collect::<Vec<_>>()
+    }
+}
+
 #[derive(Debug, Default)]
 pub struct MyGreeter {}
 
@@ -24,7 +45,8 @@ impl Greeter for MyGreeter {
         &self,
         request: Request<HelloRequest>, // Accept request of type HelloRequest
     ) -> Result<Response<HelloReply>, Status> {
-        let parent_cx = global::get_text_map_propagator(|prop| prop.extract(request.metadata()));
+        let parent_cx =
+            global::get_text_map_propagator(|prop| prop.extract(&MetadataMap(request.metadata())));
         let span = global::tracer("greeter").start_with_context("Processing reply", parent_cx);
         span.set_attribute(KeyValue::new("request", format!("{:?}", request)));
 

opentelemetry/Cargo.toml

@@ -34,7 +34,6 @@ serde = { version = "1.0", features = ["derive", "rc"], optional = true }
 http = { version = "0.2", optional = true }
 thiserror = "1"
 tokio = { version = "0.2", default-features = false, features = ["rt-core", "blocking", "time", "stream"], optional = true }
-tonic = { version = "0.3", default-features = false, optional = true }
 reqwest = { version = "0.10", default-features = false, features = ["blocking"], optional = true }
 surf = { version = "2.0", default-features = false, optional = true }
 

opentelemetry/src/propagation/mod.rs

@@ -228,38 +228,6 @@ impl Extractor for http::HeaderMap {
     }
 }
 
-#[cfg(feature = "tonic")]
-#[cfg_attr(docsrs, doc(cfg(feature = "tonic")))]
-impl Injector for tonic::metadata::MetadataMap {
-    /// Set a key and value in the MetadataMap.  Does nothing if the key or value are not valid inputs
-    fn set(&mut self, key: &str, value: String) {
-        if let Ok(key) = tonic::metadata::MetadataKey::from_bytes(key.as_bytes()) {
-            if let Ok(val) = tonic::metadata::MetadataValue::from_str(&value) {
-                self.insert(key, val);
-            }
-        }
-    }
-}
-
-#[cfg(feature = "tonic")]
-#[cfg_attr(docsrs, doc(cfg(feature = "tonic")))]
-impl Extractor for tonic::metadata::MetadataMap {
-    /// Get a value for a key from the MetadataMap.  If the value can't be converted to &str, returns None
-    fn get(&self, key: &str) -> Option<&str> {
-        self.get(key).and_then(|metadata| metadata.to_str().ok())
-    }
-
-    /// Collect all the keys from the MetadataMap.
-    fn keys(&self) -> Vec<&str> {
-        self.keys()
-            .map(|key| match key {
-                tonic::metadata::KeyRef::Ascii(v) => v.as_str(),
-                tonic::metadata::KeyRef::Binary(v) => v.as_str(),
-            })
-            .collect::<Vec<_>>()
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;