+ spray: external naming for traces and segments, related to #65

4 files changed, 90 insertions, 56 deletions

diff --git a/kamon-spray/src/main/resources/reference.conf b/kamon-spray/src/main/resources/reference.conf
index d497e681..9fed5a2b 100644
--- a/kamon-spray/src/main/resources/reference.conf
+++ b/kamon-spray/src/main/resources/reference.conf
@@ -16,6 +16,9 @@ kamon {
     #    in the `HttpRequest` headers.
     automatic-trace-token-propagation = true
 
+    # Fully qualified name of the implementation of kamon.spray.SprayNameGenerator that will be used for assigning names
+    # to traces and client http segments.
+    name-generator = kamon.spray.SimpleSprayNameGenerator
 
     client {
       # Strategy used for automatic trace segment generation when issue requests with spray-client. The possible values
diff --git a/kamon-spray/src/main/scala/kamon/spray/Spray.scala b/kamon-spray/src/main/scala/kamon/spray/Spray.scala
index 76adb214..4a0fd74e 100644
--- a/kamon-spray/src/main/scala/kamon/spray/Spray.scala
+++ b/kamon-spray/src/main/scala/kamon/spray/Spray.scala
@@ -43,6 +43,9 @@ class SprayExtension(private val system: ExtendedActorSystem) extends Kamon.Exte
   val httpServerMetrics = Kamon(Metrics)(system).register(HttpServerMetrics, HttpServerMetrics.Factory).get
   // It's safe to assume that HttpServerMetrics will always exist because there is no particular filter for it.
 
+  private val nameGeneratorFQN = config.getString("name-generator")
+  private val nameGenerator: SprayNameGenerator = system.dynamicAccess.createInstanceFor[SprayNameGenerator](nameGeneratorFQN, Nil).get // let's bubble up any problems.
+
   val clientSegmentCollectionStrategy: ClientSegmentCollectionStrategy.Strategy =
     config.getString("client.segment-collection-strategy") match {
       case "pipelining" ⇒ ClientSegmentCollectionStrategy.Pipelining
@@ -51,6 +54,19 @@ class SprayExtension(private val system: ExtendedActorSystem) extends Kamon.Exte
         s"only pipelining and internal are valid options.")
     }
 
-  // Later we should expose a way for the user to customize this.
-  def assignHttpClientRequestName(request: HttpRequest): String = request.uri.authority.host.address
+  def generateTraceName(request: HttpRequest): String = nameGenerator.generateTraceName(request)
+  def generateRequestLevelApiSegmentName(request: HttpRequest): String = nameGenerator.generateRequestLevelApiSegmentName(request)
+  def generateHostLevelApiSegmentName(request: HttpRequest): String = nameGenerator.generateHostLevelApiSegmentName(request)
+}
+
+trait SprayNameGenerator {
+  def generateTraceName(request: HttpRequest): String
+  def generateRequestLevelApiSegmentName(request: HttpRequest): String
+  def generateHostLevelApiSegmentName(request: HttpRequest): String
+}
+
+class SimpleSprayNameGenerator extends SprayNameGenerator {
+  def generateRequestLevelApiSegmentName(request: HttpRequest): String = request.method.value + ": " + request.uri.path
+  def generateTraceName(request: HttpRequest): String = request.method.value + ": " + request.uri.path
+  def generateHostLevelApiSegmentName(request: HttpRequest): String = request.uri.authority.host.address
 }
diff --git a/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala b/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala
index cfd204df..94fc3572 100644
--- a/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala
+++ b/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala
@@ -18,7 +18,7 @@ package spray.can.client
 
 import org.aspectj.lang.annotation._
 import org.aspectj.lang.ProceedingJoinPoint
-import spray.http.{ HttpHeader, HttpResponse, HttpMessageEnd, HttpRequest }
+import spray.http._
 import spray.http.HttpHeaders.RawHeader
 import kamon.trace._
 import kamon.Kamon
@@ -31,60 +31,79 @@ import akka.util.Timeout
 class ClientRequestInstrumentation {
 
   @DeclareMixin("spray.can.client.HttpHostConnector.RequestContext")
-  def mixin: SegmentAware = SegmentAware.default
+  def mixinTraceContextAwareToRequestContext: TraceContextAware = TraceContextAware.default
+
+  @DeclareMixin("spray.can.client.HttpHostConnector.RequestContext")
+  def mixinSegmentAwareToRequestContext: SegmentAware = SegmentAware.default
+
+  @DeclareMixin("spray.http.HttpRequest")
+  def mixinSegmentAwareToHttpRequest: SegmentAware = SegmentAware.default
 
   @Pointcut("execution(spray.can.client.HttpHostConnector.RequestContext.new(..)) && this(requestContext) && args(request, *, *, *)")
-  def requestContextCreation(requestContext: SegmentAware, request: HttpRequest): Unit = {}
+  def requestContextCreation(requestContext: SegmentAware with TraceContextAware, request: HttpRequest): Unit = {}
 
   @After("requestContextCreation(requestContext, request)")
-  def afterRequestContextCreation(requestContext: SegmentAware, request: HttpRequest): Unit = {
-    // The RequestContext will be copied when a request needs to be retried but we are only interested in creating the
-    // segment the first time we create one.
+  def afterRequestContextCreation(requestContext: SegmentAware with TraceContextAware, request: HttpRequest): Unit = {
+    // This read to requestContext.traceContext takes care of initializing the aspect timely.
+    requestContext.traceContext
 
-    // The read to ctx.segmentCompletionHandle should take care of initializing the aspect timely.
-    if (requestContext.segment.isEmpty) {
-      TraceRecorder.currentContext match {
-        case ctx: DefaultTraceContext ⇒
-          val sprayExtension = Kamon(Spray)(ctx.system)
+    TraceRecorder.withTraceContextAndSystem { (ctx, system) ⇒
+      val sprayExtension = Kamon(Spray)(system)
 
-          if (sprayExtension.clientSegmentCollectionStrategy == ClientSegmentCollectionStrategy.Internal) {
-            val clientRequestName = sprayExtension.assignHttpClientRequestName(request)
-            val segment = ctx.startSegment(clientRequestName, SegmentMetricIdentityLabel.HttpClient)
+      if (sprayExtension.clientSegmentCollectionStrategy == ClientSegmentCollectionStrategy.Internal) {
+        if (requestContext.segment.isEmpty) {
+          val clientRequestName = sprayExtension.generateHostLevelApiSegmentName(request)
+          val segment = ctx.startSegment(clientRequestName, SegmentMetricIdentityLabel.HttpClient)
+          requestContext.segment = segment
+        }
 
-            requestContext.segment = segment
-          }
+      } else {
 
-        case EmptyTraceContext ⇒ // Nothing to do here.
+        // We have a Request Level API, let's just make sure that we rename it accordingly. The reason for assigning a
+        // name again here is that when the request was initially sent it might not have the Host information available
+        // and it might be important to decide a proper segment name.
+
+        val clientRequestName = sprayExtension.generateHostLevelApiSegmentName(request)
+        request.asInstanceOf[SegmentAware].segment.rename(clientRequestName)
       }
     }
   }
 
   @Pointcut("execution(* spray.can.client.HttpHostConnector.RequestContext.copy(..)) && this(old)")
-  def copyingRequestContext(old: SegmentAware): Unit = {}
+  def copyingRequestContext(old: TraceContextAware): Unit = {}
 
   @Around("copyingRequestContext(old)")
-  def aroundCopyingRequestContext(pjp: ProceedingJoinPoint, old: SegmentAware): Any = {
+  def aroundCopyingRequestContext(pjp: ProceedingJoinPoint, old: TraceContextAware): Any = {
     TraceRecorder.withInlineTraceContextReplacement(old.traceContext) {
       pjp.proceed()
     }
   }
 
   @Pointcut("execution(* spray.can.client.HttpHostConnectionSlot.dispatchToCommander(..)) && args(requestContext, message)")
-  def dispatchToCommander(requestContext: SegmentAware, message: Any): Unit = {}
+  def dispatchToCommander(requestContext: TraceContextAware, message: Any): Unit = {}
 
   @Around("dispatchToCommander(requestContext, message)")
-  def aroundDispatchToCommander(pjp: ProceedingJoinPoint, requestContext: SegmentAware, message: Any) = {
+  def aroundDispatchToCommander(pjp: ProceedingJoinPoint, requestContext: TraceContextAware, message: Any): Any = {
     if (requestContext.traceContext.nonEmpty) {
       TraceRecorder.withInlineTraceContextReplacement(requestContext.traceContext) {
         if (message.isInstanceOf[HttpMessageEnd])
-          requestContext.segment.finish()
+          requestContext.asInstanceOf[SegmentAware].segment.finish()
 
         pjp.proceed()
       }
-
     } else pjp.proceed()
   }
 
+  @Pointcut("execution(* spray.http.HttpRequest.copy(..)) && this(old)")
+  def copyingHttpRequest(old: SegmentAware): Unit = {}
+
+  @Around("copyingHttpRequest(old)")
+  def aroundCopyingHttpRequest(pjp: ProceedingJoinPoint, old: SegmentAware): Any = {
+    val copiedHttpRequest = pjp.proceed().asInstanceOf[SegmentAware]
+    copiedHttpRequest.segment = old.segment
+    copiedHttpRequest
+  }
+
   @Pointcut("execution(* spray.client.pipelining$.sendReceive(akka.actor.ActorRef, *, *)) && args(transport, ec, timeout)")
   def requestLevelApiSendReceive(transport: ActorRef, ec: ExecutionContext, timeout: Timeout): Unit = {}
 
@@ -93,46 +112,42 @@ class ClientRequestInstrumentation {
     val originalSendReceive = pjp.proceed().asInstanceOf[HttpRequest ⇒ Future[HttpResponse]]
 
     (request: HttpRequest) ⇒ {
-      val responseFuture = originalSendReceive.apply(request)
-
-      TraceRecorder.currentContext match {
-        case ctx: DefaultTraceContext ⇒
-          val sprayExtension = Kamon(Spray)(ctx.system)
+      TraceRecorder.withTraceContextAndSystem { (ctx, system) ⇒
+        val sprayExtension = Kamon(Spray)(system)
+        val segment =
+          if (sprayExtension.clientSegmentCollectionStrategy == ClientSegmentCollectionStrategy.Pipelining)
+            ctx.startSegment(sprayExtension.generateRequestLevelApiSegmentName(request), SegmentMetricIdentityLabel.HttpClient)
+          else
+            EmptyTraceContext.EmptySegment
 
-          if (sprayExtension.clientSegmentCollectionStrategy == ClientSegmentCollectionStrategy.Pipelining) {
-            val clientRequestName = sprayExtension.assignHttpClientRequestName(request)
-            val segment = ctx.startSegment(clientRequestName, SegmentMetricIdentityLabel.HttpClient)
+        request.asInstanceOf[SegmentAware].segment = segment
 
-            responseFuture.onComplete { result ⇒
-              segment.finish()
-            }(ec)
-          }
+        val responseFuture = originalSendReceive.apply(request)
+        responseFuture.onComplete { result ⇒
+          segment.finish()
+        }(ec)
 
-        case EmptyTraceContext ⇒ // Nothing to do here.
-      }
+        responseFuture
 
-      responseFuture
+      } getOrElse (originalSendReceive.apply(request))
     }
-
   }
 
-  @Pointcut("call(* spray.http.HttpMessage.withDefaultHeaders(*)) && within(spray.can.client.HttpHostConnector) && args(defaultHeaders)")
-  def includingDefaultHeadersAtHttpHostConnector(defaultHeaders: List[HttpHeader]): Unit = {}
+  @Pointcut("execution(* spray.http.HttpMessage.withDefaultHeaders(*)) && this(request) && args(defaultHeaders)")
+  def includingDefaultHeadersAtHttpHostConnector(request: HttpMessage, defaultHeaders: List[HttpHeader]): Unit = {}
 
-  @Around("includingDefaultHeadersAtHttpHostConnector(defaultHeaders)")
-  def aroundIncludingDefaultHeadersAtHttpHostConnector(pjp: ProceedingJoinPoint, defaultHeaders: List[HttpHeader]): Any = {
-    val modifiedHeaders = TraceRecorder.currentContext match {
-      case ctx: DefaultTraceContext ⇒
-        val sprayExtension = Kamon(Spray)(ctx.system)
+  @Around("includingDefaultHeadersAtHttpHostConnector(request, defaultHeaders)")
+  def aroundIncludingDefaultHeadersAtHttpHostConnector(pjp: ProceedingJoinPoint, request: HttpMessage, defaultHeaders: List[HttpHeader]): Any = {
 
-        if (sprayExtension.includeTraceToken)
-          RawHeader(sprayExtension.traceTokenHeaderName, ctx.token) :: defaultHeaders
-        else
-          defaultHeaders
+    val modifiedHeaders = TraceRecorder.withTraceContextAndSystem { (ctx, system) ⇒
+      val sprayExtension = Kamon(Spray)(system)
+      if (sprayExtension.includeTraceToken)
+        RawHeader(sprayExtension.traceTokenHeaderName, ctx.token) :: defaultHeaders
+      else
+        defaultHeaders
 
-      case EmptyTraceContext ⇒ defaultHeaders
-    }
+    } getOrElse (defaultHeaders)
 
-    pjp.proceed(Array(modifiedHeaders))
+    pjp.proceed(Array[AnyRef](request, modifiedHeaders))
   }
 }
diff --git a/kamon-spray/src/main/scala/spray/can/server/ServerRequestInstrumentation.scala b/kamon-spray/src/main/scala/spray/can/server/ServerRequestInstrumentation.scala
index 74d98564..eb25412b 100644
--- a/kamon-spray/src/main/scala/spray/can/server/ServerRequestInstrumentation.scala
+++ b/kamon-spray/src/main/scala/spray/can/server/ServerRequestInstrumentation.scala
@@ -39,7 +39,7 @@ class ServerRequestInstrumentation {
     val system: ActorSystem = openRequest.asInstanceOf[OpenRequest].context.actorContext.system
     val sprayExtension = Kamon(Spray)(system)
 
-    val defaultTraceName: String = request.method.value + ": " + request.uri.path
+    val defaultTraceName = sprayExtension.generateTraceName(request)
     val token = if (sprayExtension.includeTraceToken) {
       request.headers.find(_.name == sprayExtension.traceTokenHeaderName).map(_.value)
     } else None