feat: Add tower tracing

opentelemetry-instrumentation-tower/CHANGELOG.md

@@ -0,0 +1,7 @@
+# Changelog
+
+## vNext
+
+### Changed
+
+* Added OpenTelemetry trace support

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"
@@ -21,12 +21,17 @@ 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-semantic-conventions = { workspace = true, features = ["semconv_experimental"] }
 pin-project-lite = { version = "0.2", default-features = false }
 tower-service = { version = "0.3", default-features = false }
 tower-layer = { version = "0.3", default-features = false }
 
 [dev-dependencies]
+tokio = { version = "1" }
+tower = { version = "0.3" }
+tower-test = { version = "0.3" }
+opentelemetry_sdk = { workspace = true, features = ["testing"] }
 
 [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