/* ===================================================
* Copyright © 2013 the kamon project <http://kamon.io/>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ========================================================== */
package spray.can.server
import org.aspectj.lang.annotation._
import kamon.trace.{ TraceContext, TraceRecorder, TraceContextAware }
import akka.actor.ActorSystem
import spray.http.{ HttpResponse, HttpMessagePartWrapper, HttpRequest }
import akka.event.Logging.Warning
import scala.Some
import kamon.Kamon
import kamon.spray.Spray
import org.aspectj.lang.ProceedingJoinPoint
import spray.http.HttpHeaders.RawHeader
@Aspect
class ServerRequestInstrumentation {
@DeclareMixin("spray.can.server.OpenRequestComponent.DefaultOpenRequest")
def mixinContextAwareToOpenRequest: TraceContextAware = TraceContextAware.default
@Pointcut("execution(spray.can.server.OpenRequestComponent$DefaultOpenRequest.new(..)) && this(openRequest) && args(*, request, *, *)")
def openRequestInit(openRequest: TraceContextAware, request: HttpRequest): Unit = {}
@After("openRequestInit(openRequest, request)")
def afterInit(openRequest: TraceContextAware, request: HttpRequest): Unit = {
val system: ActorSystem = openRequest.asInstanceOf[OpenRequest].context.actorContext.system
val sprayExtension = Kamon(Spray)(system)
val defaultTraceName: String = request.method.value + ": " + request.uri.path
val token = if (sprayExtension.includeTraceToken) {
request.headers.find(_.name == sprayExtension.traceTokenHeaderName).map(_.value)
} else None
TraceRecorder.start(defaultTraceName, token)(system)
// Necessary to force initialization of traceContext when initiating the request.
openRequest.traceContext
}
@Pointcut("execution(* spray.can.server.ServerFrontend$$anon$2$$anon$1.spray$can$server$ServerFrontend$$anon$$anon$$openNewRequest(..))")
def openNewRequest(): Unit = {}
@After("openNewRequest()")
def afterOpenNewRequest(): Unit = {
TraceRecorder.clearContext
}
@Pointcut("execution(* spray.can.server.OpenRequestComponent$DefaultOpenRequest.handleResponseEndAndReturnNextOpenRequest(..)) && target(openRequest) && args(response)")
def openRequestCreation(openRequest: TraceContextAware, response: HttpMessagePartWrapper): Unit = {}
@Around("openRequestCreation(openRequest, response)")
def afterFinishingRequest(pjp: ProceedingJoinPoint, openRequest: TraceContextAware, response: HttpMessagePartWrapper): Any = {
val incomingContext = TraceRecorder.currentContext
val storedContext = openRequest.traceContext
verifyTraceContextConsistency(incomingContext, storedContext)
val proceedResult = incomingContext match {
case None ⇒ pjp.proceed()
case Some(traceContext) ⇒
val sprayExtension = Kamon(Spray)(traceContext.system)
if (sprayExtension.includeTraceToken) {
val responseWithHeader = includeTraceTokenIfPossible(response, sprayExtension.traceTokenHeaderName, traceContext.token)
pjp.proceed(Array(openRequest, responseWithHeader))
} else pjp.proceed
}
TraceRecorder.finish()
proceedResult
}
def verifyTraceContextConsistency(incomingTraceContext: Option[TraceContext], storedTraceContext: Option[TraceContext]): Unit = {
for (original ← storedTraceContext) {
incomingTraceContext match {
case Some(incoming) if original.token != incoming.token ⇒
publishWarning(s"Different ids when trying to close a Trace, original: [$original] - incoming: [$incoming]", incoming.system)
case Some(_) ⇒ // nothing to do here.
case None ⇒
publishWarning(s"Trace context not present while closing the Trace: [$original]", original.system)
}
}
def publishWarning(text: String, system: ActorSystem): Unit =
system.eventStream.publish(Warning("", classOf[ServerRequestInstrumentation], text))
}
def includeTraceTokenIfPossible(response: HttpMessagePartWrapper, traceTokenHeaderName: String, token: String): HttpMessagePartWrapper =
response match {
case response: HttpResponse ⇒ response.withHeaders(RawHeader(traceTokenHeaderName, token))
case other ⇒ other
}
}