feat(trace): add TelemetryResourceDetector (#899)

Author: TommyCpp

opentelemetry-sdk/src/resource/mod.rs

@@ -18,14 +18,17 @@
 //! - [`EnvResourceDetector`] - detect resource from environmental variables.
 //! - [`OsResourceDetector`] - detect OS from runtime.
 //! - [`ProcessResourceDetector`] - detect process information.
+//! - [`TelemetryResourceDetector`] - detect telemetry SDK's information.
 mod env;
 mod os;
 mod process;
+mod telemetry;
 
 pub use env::EnvResourceDetector;
 pub use env::SdkProvidedResourceDetector;
 pub use os::OsResourceDetector;
 pub use process::ProcessResourceDetector;
+pub use telemetry::TelemetryResourceDetector;
 
 #[cfg(feature = "metrics")]
 use opentelemetry_api::attributes;
@@ -242,7 +245,7 @@ impl<'a> IntoIterator for &'a Resource {
 /// ResourceDetector detects OpenTelemetry resource information
 ///
 /// Implementations of this trait can be passed to
-/// the `Resource::from_detectors` function to generate a Resource from the merged information.
+/// the [`Resource::from_detectors`] function to generate a Resource from the merged information.
 pub trait ResourceDetector {
     /// detect returns an initialized Resource based on gathered information.
     ///

opentelemetry-sdk/src/resource/telemetry.rs

@@ -0,0 +1,27 @@
+use crate::resource::ResourceDetector;
+use crate::Resource;
+use opentelemetry_api::KeyValue;
+use std::time::Duration;
+
+/// Detect the telemetry SDK information used to capture data recorded by the instrumentation libraries.
+///
+/// It provides:
+/// - The name of the telemetry SDK(`telemetry.sdk.name`). It will be `opentelemetry` for SDK provided by opentelemetry project.
+/// - The language of the telemetry SDK(`telemetry.sdk.language`). It will be `rust` for this SDK.
+/// - The version of the telemetry SDK(`telemetry.sdk.version`). It will be current `opentelemetry_sdk` crate version.
+///
+/// Note that the `telemetry.auto.version` is not provided as of now.
+///
+/// See [semantic conventions](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/resource/semantic_conventions/README.md#telemetry-sdk) for details.
+#[derive(Debug)]
+pub struct TelemetryResourceDetector;
+
+impl ResourceDetector for TelemetryResourceDetector {
+    fn detect(&self, _timeout: Duration) -> Resource {
+        Resource::new(vec![
+            KeyValue::new("telemetry.sdk.name", "opentelemetry"),
+            KeyValue::new("telemetry.sdk.language", "rust"),
+            KeyValue::new("telemetry.sdk.version", env!("CARGO_PKG_VERSION")),
+        ])
+    }
+}