feat: Add tower tracing

opentelemetry-instrumentation-tower/CHANGELOG.md

@@ -4,6 +4,13 @@
 
 ### Changed
 
+* **BREAKING**: Removed `with_meter()` method. The middleware now uses global meter and tracer providers by default via `opentelemetry::global::meter()` and `opentelemetry::global::tracer()`, with optional overrides via `with_tracer_provider()` and `with_meter_provider()` methods.
+* **BREAKING**: Renamed types. Use the new names:
+  - `HTTPMetricsLayer` → `HTTPLayer`
+  - `HTTPMetricsService` → `HTTPService`
+  - `HTTPMetricsResponseFuture` → `HTTPResponseFuture`
+  - `HTTPMetricsLayerBuilder` → `HTTPLayerBuilder`
+* Added OpenTelemetry trace support
 * Migrate to use `opentelemetry-semantic-conventions` package for metric names and attribute keys instead of hardcoded strings
 * Add dependency on otel semantic conventions crate and use constants from it instead of hardcoded attribute names. The values are unchanged
   - `HTTP_SERVER_ACTIVE_REQUESTS_METRIC` now uses `semconv::metric::HTTP_SERVER_ACTIVE_REQUESTS`
@@ -20,6 +27,37 @@
 
 * Add comprehensive test coverage for all HTTP server metrics with attribute validation
 
+### Migration Guide
+
+#### API Changes
+Before:
+```rust
+use opentelemetry_instrumentation_tower::HTTPMetricsLayerBuilder;
+
+let layer = HTTPMetricsLayerBuilder::builder()
+    .with_meter(meter)
+    .build()
+    .unwrap();
+```
+
+After:
+```rust
+use opentelemetry_instrumentation_tower::HTTPLayer;
+
+// Set global providers first
+global::set_meter_provider(meter_provider);
+global::set_tracer_provider(tracer_provider); // for tracing support
+
+// Then create the layer - simple API using global providers
+let layer = HTTPLayer::new();
+```
+
+#### Type Name Changes
+- Replace `HTTPMetricsLayerBuilder` with `HTTPLayerBuilder`
+- Replace `HTTPMetricsLayer` with `HTTPLayer`
+- Replace `HTTPMetricsService` with `HTTPService`
+- Replace `HTTPMetricsResponseFuture` with `HTTPResponseFuture`
+
 ## v0.16.0
 
 Initial release of OpenTelemetry Tower instrumentation middleware for HTTP metrics collection.

opentelemetry-instrumentation-tower/Cargo.toml

@@ -5,7 +5,7 @@ rust-version = "1.75.0"
 
 version = "0.16.0"
 license = "Apache-2.0"
-description = "OpenTelemetry Metrics Middleware for Tower-compatible Rust HTTP servers"
+description = "OpenTelemetry Metrics and Tracing Middleware for Tower-compatible Rust HTTP servers"
 homepage = "https://github.com/open-telemetry/opentelemetry-rust-contrib"
 repository = "https://github.com/open-telemetry/opentelemetry-rust-contrib"
 documentation = "https://docs.rs/tower-otel-http-metrics"
@@ -21,7 +21,8 @@ axum = { features = ["matched-path", "macros"], version = "0.8", default-feature
 futures-util = { version = "0.3", default-features = false }
 http = { version = "1", features = ["std"], default-features = false }
 http-body = { version = "1", default-features = false }
-opentelemetry = { workspace = true, features = ["futures", "metrics"]}
+opentelemetry = { workspace = true, features = ["futures", "metrics", "trace"] }
+opentelemetry_sdk = { workspace = true, features = ["trace"] }
 opentelemetry-semantic-conventions = { workspace = true, features = ["semconv_experimental"] }
 pin-project-lite = { version = "0.2", default-features = false }
 tower-service = { version = "0.3", default-features = false }
@@ -31,6 +32,7 @@ tower-layer = { version = "0.3", default-features = false }
 opentelemetry_sdk = { workspace = true, features = ["metrics", "testing"] }
 tokio = { version = "1.0", features = ["macros", "rt"] }
 tower = { version = "0.5", features = ["util"] }
+tower-test = { version = "0.4" }
 
 [lints]
 workspace = true

opentelemetry-instrumentation-tower/README.md

@@ -1,6 +1,38 @@
-# Tower OTEL Metrics Middleware
+# Tower OTEL HTTP Instrumentation Middleware
 
-OpenTelemetry Metrics Middleware for Tower-compatible Rust HTTP servers.
+OpenTelemetry HTTP Metrics and Tracing Middleware for Tower-compatible Rust HTTP servers.
+
+This middleware provides both metrics and distributed tracing for HTTP requests, following OpenTelemetry semantic conventions.
+
+## Features
+
+- **HTTP Metrics**: Request duration, active requests, request/response body sizes
+- **Distributed Tracing**: HTTP spans with semantic attributes
+- **Semantic Conventions**: Uses OpenTelemetry semantic conventions for consistent attribute naming
+- **Flexible Configuration**: Support for custom attribute extractors and tracer configuration
+- **Framework Support**: Works with any Tower-compatible HTTP framework (Axum, Hyper, Tonic etc.)
+
+## Usage
+
+## Metrics
+
+The middleware exports the following metrics:
+
+- `http.server.request.duration` - Duration of HTTP requests
+- `http.server.active_requests` - Number of active HTTP requests  
+- `http.server.request.body.size` - Size of HTTP request bodies
+- `http.server.response.body.size` - Size of HTTP response bodies
+
+## Tracing
+
+HTTP spans are created with the following attributes (following OpenTelemetry semantic conventions):
+
+- `http.request.method` - HTTP method
+- `url.scheme` - URL scheme (http/https)
+- `url.path` - Request path
+- `url.full` - Full URL
+- `user_agent.original` - User agent string
+- `http.response.status_code` - HTTP response status code
 
 ## Examples
 

opentelemetry-instrumentation-tower/examples/axum-http-service/src/main.rs

@@ -1,7 +1,9 @@
 use axum::routing::{get, post, put, Router};
 use bytes::Bytes;
 use opentelemetry::global;
-use opentelemetry_instrumentation_tower as otel_tower_metrics;
+use opentelemetry_instrumentation_tower::HTTPLayer;
+use opentelemetry_otlp::MetricExporter;
+use opentelemetry_sdk::metrics::{PeriodicReader, SdkMeterProvider};
 use std::time::Duration;
 
 const SERVICE_NAME: &str = "example-axum-http-service";
@@ -40,28 +42,24 @@ async fn handle() -> Bytes {
 
 #[tokio::main]
 async fn main() {
-    let exporter = opentelemetry_otlp::MetricExporter::builder()
+    let exporter = MetricExporter::builder()
         .with_tonic()
         // .with_endpoint("http://localhost:4317")  // default; leave out in favor of env var OTEL_EXPORTER_OTLP_ENDPOINT
         .build()
         .unwrap();
 
-    let reader = opentelemetry_sdk::metrics::PeriodicReader::builder(exporter)
+    let reader = PeriodicReader::builder(exporter)
         .with_interval(_OTEL_METRIC_EXPORT_INTERVAL)
         .build();
 
-    let meter_provider = opentelemetry_sdk::metrics::SdkMeterProvider::builder()
+    let meter_provider = SdkMeterProvider::builder()
         .with_reader(reader)
         .with_resource(init_otel_resource())
         .build();
 
     global::set_meter_provider(meter_provider);
-    // init our otel metrics middleware
-    let global_meter = global::meter(SERVICE_NAME);
-    let otel_metrics_service_layer = otel_tower_metrics::HTTPMetricsLayerBuilder::builder()
-        .with_meter(global_meter)
-        .build()
-        .unwrap();
+
+    let otel_metrics_service_layer = HTTPLayer::new();
 
     let app = Router::new()
         .route("/", get(handle))

opentelemetry-instrumentation-tower/examples/hyper-http-service/src/main.rs

@@ -2,7 +2,9 @@ use http_body_util::Full;
 use hyper::body::Bytes;
 use hyper::{Request, Response};
 use opentelemetry::global;
-use opentelemetry_instrumentation_tower as otel_tower_metrics;
+use opentelemetry_instrumentation_tower::HTTPLayer;
+use opentelemetry_otlp::MetricExporter;
+use opentelemetry_sdk::metrics::{PeriodicReader, SdkMeterProvider};
 use std::convert::Infallible;
 use std::net::SocketAddr;
 use std::time::Duration;
@@ -45,28 +47,24 @@ async fn handle(_req: Request<hyper::body::Incoming>) -> Result<Response<Full<By
 
 #[tokio::main]
 async fn main() {
-    let exporter = opentelemetry_otlp::MetricExporter::builder()
+    let exporter = MetricExporter::builder()
         .with_tonic()
         // .with_endpoint("http://localhost:4317")  // default; leave out in favor of env var OTEL_EXPORTER_OTLP_ENDPOINT
         .build()
         .unwrap();
 
-    let reader = opentelemetry_sdk::metrics::PeriodicReader::builder(exporter)
+    let reader = PeriodicReader::builder(exporter)
         .with_interval(_OTEL_METRIC_EXPORT_INTERVAL)
         .build();
 
-    let meter_provider = opentelemetry_sdk::metrics::SdkMeterProvider::builder()
+    let meter_provider = SdkMeterProvider::builder()
         .with_reader(reader)
         .with_resource(init_otel_resource())
         .build();
 
     global::set_meter_provider(meter_provider);
-    // init our otel metrics middleware
-    let global_meter = global::meter(SERVICE_NAME);
-    let otel_metrics_service_layer = otel_tower_metrics::HTTPMetricsLayerBuilder::builder()
-        .with_meter(global_meter)
-        .build()
-        .unwrap();
+
+    let otel_metrics_service_layer = HTTPLayer::new();
 
     let tower_service = ServiceBuilder::new()
         .layer(otel_metrics_service_layer)