/* =========================================================================================
* Copyright © 2013-2014 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 kamon.play.instrumentation
import kamon.Kamon
import kamon.play.{ Play, PlayExtension }
import kamon.trace.{ TraceContextAware, TraceRecorder }
import org.aspectj.lang.ProceedingJoinPoint
import org.aspectj.lang.annotation._
import play.api.Routes
import play.api.mvc.Results._
import play.api.mvc._
import play.libs.Akka
@Aspect
class RequestInstrumentation {
import kamon.play.instrumentation.RequestInstrumentation._
@DeclareMixin("play.api.mvc.RequestHeader+")
def mixinContextAwareNewRequest: TraceContextAware = TraceContextAware.default
@After("execution(* play.api.GlobalSettings+.onStart(*)) && args(application)")
def afterApplicationStart(application: play.api.Application): Unit = {
Kamon(Play)(Akka.system())
}
@Before("call(* play.api.GlobalSettings+.onRouteRequest(..)) && args(requestHeader)")
def beforeRouteRequest(requestHeader: RequestHeader): Unit = {
val system = Akka.system()
val playExtension = Kamon(Play)(system)
val defaultTraceName = playExtension.generateTraceName(requestHeader)
val token = if (playExtension.includeTraceToken) {
requestHeader.headers.toSimpleMap.find(_._1 == playExtension.traceTokenHeaderName).map(_._2)
} else None
TraceRecorder.start(defaultTraceName, token)(system)
}
@Around("execution(* play.api.GlobalSettings+.doFilter(*)) && args(next)")
def aroundDoFilter(pjp: ProceedingJoinPoint, next: EssentialAction): Any = {
val essentialAction = (requestHeader: RequestHeader) ⇒ {
// TODO: Move to a Kamon-specific dispatcher.
val executor = Kamon(Play)(Akka.system()).defaultDispatcher
def onResult(result: Result): Result = {
TraceRecorder.withTraceContextAndSystem { (ctx, system) ⇒
ctx.finish()
val playExtension = Kamon(Play)(system)
recordHttpServerMetrics(result.header, ctx.name, playExtension)
if (playExtension.includeTraceToken)
result.withHeaders(playExtension.traceTokenHeaderName -> ctx.token)
else
result
} getOrElse (result)
}
//override the current trace name
normaliseTraceName(requestHeader).map(TraceRecorder.rename(_))
// Invoke the action
next(requestHeader).map(onResult)(executor)
}
pjp.proceed(Array(EssentialAction(essentialAction)))
}
@Before("execution(* play.api.GlobalSettings+.onError(..)) && args(request, ex)")
def beforeOnError(request: TraceContextAware, ex: Throwable): Unit = TraceRecorder.withTraceContextAndSystem { (ctx, system) ⇒
recordHttpServerMetrics(InternalServerError.header, ctx.name, Kamon(Play)(system))
}
private def recordHttpServerMetrics(header: ResponseHeader, traceName: String, playExtension: PlayExtension): Unit =
playExtension.httpServerMetrics.recordResponse(traceName, header.status.toString)
}
object RequestInstrumentation {
import java.util.Locale
import scala.collection.concurrent.TrieMap
private val cache = TrieMap.empty[String, String]
def normaliseTraceName(requestHeader: RequestHeader): Option[String] = requestHeader.tags.get(Routes.ROUTE_VERB).map({ verb ⇒
val path = requestHeader.tags(Routes.ROUTE_PATTERN)
cache.getOrElseUpdate(s"$verb$path", {
val traceName = {
// Convert paths of form GET /foo/bar/$paramname<regexp>/blah to foo.bar.paramname.blah.get
val p = path.replaceAll("""\$([^<]+)<[^>]+>""", "$1").replace('/', '.').dropWhile(_ == '.')
val normalisedPath = {
if (p.lastOption.filter(_ != '.').isDefined) s"$p."
else p
}
s"$normalisedPath${verb.toLowerCase(Locale.ENGLISH)}"
}
traceName
})
})
}