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/* ===================================================
* 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.instrumentation
import kamon.trace.TraceLocal.{ HttpContext, HttpContextKey }
import org.aspectj.lang.annotation._
import kamon.trace._
import spray.can.server.OpenRequest
import spray.http.{ HttpResponse, HttpMessagePartWrapper, HttpRequest }
import kamon.Kamon
import kamon.spray.{ SprayExtension, Spray }
import org.aspectj.lang.ProceedingJoinPoint
import spray.http.HttpHeaders.RawHeader
@Aspect
class ServerRequestInstrumentation {
import 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 = {
import Kamon.tracer
val sprayExtension = Kamon(Spray)
val defaultTraceName = sprayExtension.generateTraceName(request)
val token = if (sprayExtension.settings.includeTraceTokenHeader) {
request.headers.find(_.name == sprayExtension.settings.traceTokenHeaderName).map(_.value)
} else None
val newContext = tracer.newContext(defaultTraceName, token)
Tracer.setCurrentContext(newContext)
// 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 = {
Tracer.clearCurrentContext
}
@Pointcut("execution(* spray.can.server.OpenRequestComponent$DefaultOpenRequest.handleResponseEndAndReturnNextOpenRequest(..)) && target(openRequest) && args(response)")
def openRequestCreation(openRequest: TraceContextAware, response: HttpMessagePartWrapper): Unit = {}
@Around("openRequestCreation(openRequest, response)")
def afterFinishingRequest(pjp: ProceedingJoinPoint, openRequest: TraceContextAware, response: HttpMessagePartWrapper): Any = {
val incomingContext = Tracer.currentContext
val storedContext = openRequest.traceContext
// The stored context is always a DefaultTraceContext if the instrumentation is running
verifyTraceContextConsistency(incomingContext, storedContext)
if (incomingContext.isEmpty)
pjp.proceed()
else {
val sprayExtension = Kamon(Spray)
val proceedResult = if (sprayExtension.settings.includeTraceTokenHeader) {
val responseWithHeader = includeTraceTokenIfPossible(response, sprayExtension.settings.traceTokenHeaderName, incomingContext.token)
pjp.proceed(Array(openRequest, responseWithHeader))
} else pjp.proceed
Tracer.currentContext.finish()
recordHttpServerMetrics(response, incomingContext.name, sprayExtension)
//store in TraceLocal useful data to diagnose errors
storeDiagnosticData(openRequest)
proceedResult
}
}
def verifyTraceContextConsistency(incomingTraceContext: TraceContext, storedTraceContext: TraceContext): Unit = {
def publishWarning(text: String): Unit =
Kamon(Spray).log.warning(text)
if (incomingTraceContext.nonEmpty) {
if (incomingTraceContext.token != storedTraceContext.token)
publishWarning(s"Different trace token found when trying to close a trace, original: [${storedTraceContext.token}] - incoming: [${incomingTraceContext.token}]")
} else
publishWarning(s"EmptyTraceContext present while closing the trace with token [${storedTraceContext.token}]")
}
def recordHttpServerMetrics(response: HttpMessagePartWrapper, traceName: String, sprayExtension: SprayExtension): Unit =
response match {
case httpResponse: HttpResponse ⇒ sprayExtension.httpServerMetrics.recordResponse(traceName, httpResponse.status.intValue.toString)
case other ⇒ // Nothing to do then.
}
def includeTraceTokenIfPossible(response: HttpMessagePartWrapper, traceTokenHeaderName: String, token: String): HttpMessagePartWrapper =
response match {
case response: HttpResponse ⇒ response.withHeaders(response.headers ::: RawHeader(traceTokenHeaderName, token) :: Nil)
case other ⇒ other
}
def storeDiagnosticData(currentContext: TraceContextAware): Unit = {
val request = currentContext.asInstanceOf[OpenRequest].request
val headers = request.headers.map(header ⇒ header.name -> header.value).toMap
val agent = headers.getOrElse(UserAgent, Unknown)
val forwarded = headers.getOrElse(XForwardedFor, Unknown)
TraceLocal.store(HttpContextKey)(HttpContext(agent, request.uri.toRelative.toString(), forwarded))
}
}
object ServerRequestInstrumentation {
val UserAgent = "User-Agent"
val XForwardedFor = "X-Forwarded-For"
val Unknown = "unknown"
}
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