Add aws log group name in Trace details if key is present in annotati…

…on object (#5)

README.md

@@ -9,3 +9,6 @@ Natchez is distributed tracing library for Scala.
 
 Please proceed to the [microsite](https://typelevel.org/natchez/) for more information.
 
+## AWS Log Group Name Configuration
+
+In our Scala application, we use the `aws_group_name` key from the annotations to set the AWS Log group name. 

modules/xray/src/main/scala/natchez/xray/XRaySpan.scala

@@ -115,7 +115,25 @@ private[xray] final case class XRaySpan[F[_]: Concurrent: Clock: Random](
  (goodKeys + ("malformed_keys" -> badKeys.keys
  .mkString(",")
  .asJson)) ++ fixedAnnotations
-
+ /*
+ * `aws_group_name` key in the annotations, when present, sets the AWS CloudWatch log group name.
+ * It is used to add log details to each trace.
+ * This is required when the log receiver container uses the X-Ray daemon image, which doesn't provide an option to set the group name.
+ */
+ val logGroupValue = allAnnotations.get("aws_group_name")
+ val awsObject = logGroupValue
+ .map(lgValue =>
+ JsonObject(
+ "aws" -> JsonObject(
+ "cloudwatch_logs" -> Json.arr(
+ JsonObject(
+ "log_group" -> lgValue
+ ).asJson
+ )
+ ).asJson
+ )
+ )
+ .getOrElse(JsonObject.empty)
  JsonObject(
  "name" -> name.asJson,
  "id" -> segmentId.asJson,
@@ -131,11 +149,12 @@ private[xray] final case class XRaySpan[F[_]: Concurrent: Clock: Random](
  "links" -> options.links.asJson,
  "span.kind" -> options.spanKind.asJson
  ).asJson
- ).deepMerge(exitCase match {
- case Canceled => JsonObject.singleton("fault", true.asJson)
- case Errored(e) => XRayException(id, e).asJsonObject
- case Succeeded => JsonObject.empty
- })
+ ).deepMerge(awsObject)
+ .deepMerge(exitCase match {
+ case Canceled => JsonObject.singleton("fault", true.asJson)
+ case Errored(e) => XRayException(id, e).asJsonObject
+ case Succeeded => JsonObject.empty
+ })
  }
 
  private def header: String =