Add feature flag for deprecated fields (#167)

* Add feature flag for deprecated fields

* revert editor format

* rename flag

* remove unnecessary cfg not

* add comment and publish old and new attributes on request_span macro

* add comment

* update changelog

* Update reqwest-tracing/CHANGELOG.md

Co-authored-by: Ethan Brierley <ethanboxx@gmail.com>

* bump version

---------

Co-authored-by: Ethan Brierley <ethanboxx@gmail.com>

reqwest-tracing/CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.5.2] - 2024-07-15
+
+### Added
+- Added feature flag, `deprecated_attributes`, for emitting [deprecated opentelemetry HTTP attributes](https://opentelemetry.io/docs/specs/semconv/http/migration-guide/) alongside the stable ones used by default
+
 ## [0.5.1] - 2024-06-28
 
 ### Added

reqwest-tracing/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "reqwest-tracing"
-version = "0.5.1"
+version = "0.5.2"
 authors = ["Rodrigo Gryzinski <rodrigo.gryzinski@truelayer.com>"]
 edition = "2018"
 description = "Opentracing middleware for reqwest."
@@ -14,7 +14,10 @@ opentelemetry_0_20 = ["opentelemetry_0_20_pkg", "tracing-opentelemetry_0_21_pkg"
 opentelemetry_0_21 = ["opentelemetry_0_21_pkg", "tracing-opentelemetry_0_22_pkg"]
 opentelemetry_0_22 = ["opentelemetry_0_22_pkg", "tracing-opentelemetry_0_23_pkg"]
 opentelemetry_0_23 = ["opentelemetry_0_23_pkg", "tracing-opentelemetry_0_24_pkg"]
-
+# This feature ensures that both the old (deprecated) and new attributes are published simultaneously.
+# By doing so, we maintain backward compatibility, allowing existing code that relies on the old attributes
+# to continue functioning while encouraging the transition to the new attributes.
+deprecated_attributes = []
 
 [dependencies]
 reqwest-middleware = { version = "0.3.0", path = "../reqwest-middleware" }
@@ -51,3 +54,4 @@ opentelemetry_stdout_0_1 = { package = "opentelemetry-stdout", version = "0.1.0"
 opentelemetry_stdout_0_2 = { package = "opentelemetry-stdout", version = "0.2.0", features = ["trace"] }
 opentelemetry_stdout_0_3 = { package = "opentelemetry-stdout", version = "0.3.0", features = ["trace"] }
 opentelemetry_stdout_0_4 = { package = "opentelemetry-stdout", version = "0.4.0", features = ["trace"] }
+

reqwest-tracing/src/lib.rs

@@ -100,5 +100,10 @@ pub use reqwest_otel_span_builder::{
     SERVER_ADDRESS, SERVER_PORT, URL_FULL, URL_SCHEME, USER_AGENT_ORIGINAL,
 };
 
+#[cfg(feature = "deprecated_attributes")]
+pub use reqwest_otel_span_builder::{
+    HTTP_HOST, HTTP_METHOD, HTTP_SCHEME, HTTP_STATUS_CODE, HTTP_URL, HTTP_USER_AGENT, NET_HOST_PORT,
+};
+
 #[doc(hidden)]
 pub mod reqwest_otel_span_macro;

reqwest-tracing/src/reqwest_otel_span_builder.rs

@@ -33,6 +33,28 @@ pub const ERROR_MESSAGE: &str = "error.message";
 /// The `error.cause_chain` field added to the span by [`reqwest_otel_span`]
 pub const ERROR_CAUSE_CHAIN: &str = "error.cause_chain";
 
+/// The `http.method` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_METHOD: &str = "http.method";
+/// The `http.scheme` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_SCHEME: &str = "http.scheme";
+/// The `http.host` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_HOST: &str = "http.host";
+/// The `http.url` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_URL: &str = "http.url";
+/// The `host.port` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const NET_HOST_PORT: &str = "net.host.port";
+/// The `http.status_code` field added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_STATUS_CODE: &str = "http.status_code";
+/// The `http.user_agent` added to the span by [`reqwest_otel_span`]
+#[cfg(feature = "deprecated_attributes")]
+pub const HTTP_USER_AGENT: &str = "http.user_agent";
+
 /// [`ReqwestOtelSpanBackend`] allows you to customise the span attached by
 /// [`TracingMiddleware`] to incoming requests.
 ///
@@ -64,6 +86,11 @@ pub fn default_on_request_success(span: &Span, response: &Response) {
         span.record(OTEL_STATUS_CODE, span_status);
     }
     span.record(HTTP_RESPONSE_STATUS_CODE, response.status().as_u16());
+    #[cfg(feature = "deprecated_attributes")]
+    {
+        span.record(HTTP_STATUS_CODE, response.status().as_u16());
+        span.record(HTTP_USER_AGENT, user_agent.as_str());
+    }
 }
 
 /// Populates default failure fields for a given [`reqwest_otel_span!`] span.
@@ -77,6 +104,10 @@ pub fn default_on_request_failure(span: &Span, e: &Error) {
     if let Error::Reqwest(e) = e {
         if let Some(status) = e.status() {
             span.record(HTTP_RESPONSE_STATUS_CODE, status.as_u16());
+            #[cfg(feature = "deprecated_attributes")]
+            {
+                span.record(HTTP_STATUS_CODE, status.as_u16());
+            }
         }
     }
 }

reqwest-tracing/src/reqwest_otel_span_macro.rs

@@ -127,6 +127,7 @@ macro_rules! reqwest_otel_span {
             let header_default = &::http::HeaderValue::from_static("");
             let user_agent = format!("{:?}", $request.headers().get("user-agent").unwrap_or(header_default)).replace('"', "");
 
+            #[cfg(not(feature = "deprecated_attributes"))]
             macro_rules! request_span {
                 ($lvl:expr) => {
                     $crate::reqwest_otel_span_macro::private::span!(
@@ -148,6 +149,36 @@ macro_rules! reqwest_otel_span {
                 }
             }
 
+            // With the deprecated attributes flag enabled, we publish both the old and new attributes.
+            #[cfg(feature = "deprecated_attributes")]
+            macro_rules! request_span {
+                ($lvl:expr) => {
+                    $crate::reqwest_otel_span_macro::private::span!(
+                        $lvl,
+                        "HTTP request",
+                        http.request.method = %method,
+                        url.scheme = %scheme,
+                        server.address = %host,
+                        server.port = %host_port,
+                        user_agent.original = %user_agent,
+                        otel.kind = "client",
+                        otel.name = %otel_name,
+                        otel.status_code = tracing::field::Empty,
+                        http.response.status_code = tracing::field::Empty,
+                        error.message = tracing::field::Empty,
+                        error.cause_chain = tracing::field::Empty,
+                        // old attributes
+                        http.method = %method,
+                        http.scheme = %scheme,
+                        http.host = %host,
+                        net.host.port = %host_port,
+                        http.user_agent = tracing::field::Empty,
+                        http.status_code = tracing::field::Empty,
+                        $($field)*
+                    )
+                }
+            }
+
             let span = match $level {
                 $crate::reqwest_otel_span_macro::private::Level::TRACE => {
                     request_span!($crate::reqwest_otel_span_macro::private::Level::TRACE)