feat(otlp): add reqwest-native-tls feature flag for HTTP transport

opentelemetry-http/CHANGELOG.md

@@ -3,6 +3,8 @@
 ## vNext
 
 - `reqwest`'s crypto backend has changed from `ring` to `aws-lc-sys`.
+- Add `reqwest-native-tls` feature flag to enable system native TLS (OpenSSL on Linux, Schannel on Windows, Secure Transport on macOS).
+- Update `reqwest-rustls` and `reqwest-rustls-webpki-roots` features to use explicit `rustls-tls` instead of `default-tls` for clarity.
 
 ## 0.31.0
 

opentelemetry-http/Cargo.toml

@@ -17,6 +17,7 @@ reqwest = ["dep:reqwest"]
 reqwest-blocking = ["dep:reqwest", "reqwest/blocking"]
 reqwest-rustls = ["dep:reqwest", "reqwest/default-tls"]
 reqwest-rustls-webpki-roots = ["dep:reqwest", "reqwest/default-tls", "reqwest/webpki-roots"]
+reqwest-native-tls = ["dep:reqwest", "reqwest/native-tls"]
 internal-logs = ["opentelemetry/internal-logs"]
 
 [dependencies]

opentelemetry-otlp/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## vNext
 
+- Add `reqwest-native-tls` feature flag to enable system native TLS (OpenSSL on Linux, Schannel on Windows, Secure Transport on macOS).
 - Fix `NoHttpClient` error when multiple HTTP client features are enabled by using priority-based selection (`reqwest-client` > `hyper-client` > `reqwest-blocking-client`). [#2994](https://github.com/open-telemetry/opentelemetry-rust/issues/2994)
 - Add partial success response handling for OTLP exporters (traces, metrics, logs) per OTLP spec. Exporters now log warnings when the server returns partial success responses with rejected items and error messages. [#865](https://github.com/open-telemetry/opentelemetry-rust/issues/865)
 - Refactor `internal-logs` feature in `opentelemetry-otlp` to reduce unnecessary dependencies[3191](https://github.com/open-telemetry/opentelemetry-rust/pull/3192)

opentelemetry-otlp/Cargo.toml

@@ -95,6 +95,7 @@ reqwest-blocking-client = ["reqwest/blocking", "opentelemetry-http/reqwest-block
 reqwest-client = ["reqwest", "opentelemetry-http/reqwest"]
 reqwest-rustls = ["reqwest", "opentelemetry-http/reqwest-rustls"]
 reqwest-rustls-webpki-roots = ["reqwest", "opentelemetry-http/reqwest-rustls-webpki-roots"]
+reqwest-native-tls = ["reqwest", "opentelemetry-http/reqwest-native-tls"]
 hyper-client = ["opentelemetry-http/hyper"]
 
 # test

opentelemetry-otlp/src/lib.rs

@@ -233,6 +233,7 @@
 //! * `reqwest-client`: Use reqwest http client.
 //! * `reqwest-rustls`: Use reqwest with TLS with system trust roots via `rustls-native-certs` crate.
 //! * `reqwest-rustls-webpki-roots`: Use reqwest with TLS with Mozilla's trust roots via `webpki-roots` crate.
+//! * `reqwest-native-tls`: Use reqwest with system native TLS (OpenSSL on Linux, Schannel on Windows, Secure Transport on macOS).
 //!
 //! # Kitchen Sink Full Configuration
 //!