add aws xray id generator (#33)

opentelemetry-aws/CHANGELOG.md

@@ -29,6 +29,7 @@
 
 - reduce `tokio` feature requirements #750
 - Update to opentelemetry v0.18.0
+- Move Xray IdGenerator from `opentelemetry-rust` to `opentelemetry-aws` [#33](https://github.com/open-telemetry/opentelemetry-rust-contrib/pull/33)
 
 ### Fixed
 

opentelemetry-aws/Cargo.toml

@@ -20,11 +20,12 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
 default = ["trace"]
-trace = ["opentelemetry/trace"]
+trace = ["opentelemetry/trace", "opentelemetry_sdk"]
 
 [dependencies]
 once_cell = "1.12"
 opentelemetry = { version = "0.21" }
+opentelemetry_sdk = { version = "0.21", optional = true }
 
 [dev-dependencies]
 opentelemetry_sdk = { version = "0.21", features = ["trace", "testing"] }

opentelemetry-aws/README.md

@@ -22,6 +22,6 @@ to AWS's telemetry platform.
 
 ## Supported component
 
-Currently, this crate only supports `XRay` propagator. Contributions are welcome.
+Currently, this crate only supports `XRay` propagator and `Xray` ID Generator. Contributions are welcome.
 
 [`OpenTelemetry`]: https://crates.io/crates/opentelemetry

opentelemetry-aws/src/trace/id_generator.rs

@@ -0,0 +1,95 @@
+use opentelemetry::trace::{SpanId, TraceId};
+use opentelemetry_sdk::trace::{IdGenerator, RandomIdGenerator};
+use std::time::{Duration, UNIX_EPOCH};
+
+/// Generates AWS X-Ray compliant Trace and Span ids.
+///
+/// Generates OpenTelemetry formatted `TraceId`'s and `SpanId`'s. The `TraceId`'s are generated so
+/// they can be backed out into X-Ray format by the [AWS X-Ray Exporter][xray-exporter] in the
+/// [OpenTelemetry Collector][otel-collector].
+///
+/// ## Trace ID Format
+///
+/// A `trace_id` consists of three numbers separated by hyphens. For example, `1-58406520-a006649127e371903a2de979`.
+/// This includes:
+///
+/// * The version number, that is, 1.
+/// * The time of the original request, in Unix epoch time, in 8 hexadecimal digits.
+/// * For example, 10:00AM December 1st, 2016 PST in epoch time is 1480615200 seconds, or 58406520 in hexadecimal digits.
+/// * A 96-bit identifier for the trace, globally unique, in 24 hexadecimal digits.
+///
+/// See the [AWS X-Ray Documentation][xray-trace-id] for more details.
+///
+/// ## Example
+///
+/// ```
+/// use opentelemetry::trace::{TraceId};
+/// use opentelemetry_sdk::trace::{self, IdGenerator, TracerProvider};
+/// use opentelemetry_aws::trace::XrayIdGenerator;
+/// let _provider: TracerProvider = TracerProvider::builder()
+///      .with_config(trace::config().with_id_generator(XrayIdGenerator::default()))
+///      .build();
+/// ```
+///
+/// [otel-collector]: https://github.com/open-telemetry/opentelemetry-collector-contrib#opentelemetry-collector-contrib
+/// [xray-exporter]: https://godoc.org/github.com/open-telemetry/opentelemetry-collector-contrib/exporter/awsxrayexporter
+/// [xray-trace-id]: https://docs.aws.amazon.com/xray/latest/devguide/xray-api-sendingdata.html#xray-api-traceids
+#[derive(Debug, Default)]
+pub struct XrayIdGenerator {
+    sdk_default_generator: RandomIdGenerator,
+}
+
+impl IdGenerator for XrayIdGenerator {
+    /// Generates a new `TraceId` that can be converted to an X-Ray Trace ID
+    fn new_trace_id(&self) -> TraceId {
+        let mut default_trace_id: String =
+            format!("{:024x}", self.sdk_default_generator.new_trace_id());
+
+        default_trace_id.truncate(24);
+
+        let epoch_time_seconds: u64 = opentelemetry::time::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or_else(|_| Duration::from_secs(0))
+            .as_secs();
+
+        TraceId::from_hex(format!("{:08x}{}", epoch_time_seconds, default_trace_id).as_str())
+            .unwrap_or(TraceId::INVALID)
+    }
+
+    /// Generates a new `SpanId` that can be converted to an X-Ray Segment ID
+    fn new_span_id(&self) -> SpanId {
+        self.sdk_default_generator.new_span_id()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::thread::sleep;
+
+    #[test]
+    fn test_trace_id_generation() {
+        let before: u64 = opentelemetry::time::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_secs();
+        sleep(Duration::from_secs(1));
+
+        let generator: XrayIdGenerator = XrayIdGenerator::default();
+        let trace_id: TraceId = generator.new_trace_id();
+
+        sleep(Duration::from_secs(1));
+        let after: u64 = opentelemetry::time::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_secs();
+
+        let trace_as_hex = trace_id.to_string();
+        let (timestamp, _xray_id) = trace_as_hex.split_at(8_usize);
+
+        let trace_time: u64 = u64::from_str_radix(timestamp, 16).unwrap();
+
+        assert!(before <= trace_time);
+        assert!(after >= trace_time);
+    }
+}

opentelemetry-aws/src/trace/mod.rs

@@ -0,0 +1,8 @@
+pub mod id_generator;
+pub mod xray_propagator;
+
+#[cfg(feature = "trace")]
+pub use xray_propagator::XrayPropagator;
+
+#[cfg(feature = "trace")]
+pub use id_generator::XrayIdGenerator;