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/* =========================================================================================
* 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
import kamon.trace.TraceLocal.{ HttpContextKey, HttpContext }
import kamon.trace._
import org.aspectj.lang.ProceedingJoinPoint
import org.aspectj.lang.annotation._
import play.api.Routes
import play.api.mvc.Results._
import play.api.mvc._
@Aspect
class RequestInstrumentation {
import RequestInstrumentation._
@DeclareMixin("play.api.mvc.RequestHeader+")
def mixinContextAwareNewRequest: TraceContextAware = TraceContextAware.default
@Before("call(* play.api.GlobalSettings.onRouteRequest(..)) && args(requestHeader)")
def beforeRouteRequest(requestHeader: RequestHeader): Unit = {
import Kamon.tracer
val playExtension = Kamon(Play)
val defaultTraceName = playExtension.generateTraceName(requestHeader)
val token = if (playExtension.includeTraceToken) {
requestHeader.headers.toSimpleMap.find(_._1 == playExtension.traceTokenHeaderName).map(_._2)
} else None
val newContext = token.map(t ⇒ tracer.newContext(defaultTraceName, t)).getOrElse(tracer.newContext(defaultTraceName))
Tracer.setCurrentContext(newContext)
}
@Around("call(* play.api.GlobalSettings.doFilter(*)) && args(next)")
def aroundDoFilter(pjp: ProceedingJoinPoint, next: EssentialAction): Any = {
val essentialAction = (requestHeader: RequestHeader) ⇒ {
val playExtension = Kamon(Play)
val executor = playExtension.defaultDispatcher
def onResult(result: Result): Result = {
Tracer.currentContext.collect { ctx ⇒
ctx.finish()
recordHttpServerMetrics(result.header, ctx.name)
if (playExtension.includeTraceToken) result.withHeaders(playExtension.traceTokenHeaderName -> ctx.token)
else result
} getOrElse result
}
//store in TraceLocal useful data to diagnose errors
storeDiagnosticData(requestHeader)
//override the current trace name
normaliseTraceName(requestHeader).map(Tracer.currentContext.rename)
// Invoke the action
next(requestHeader).map(onResult)(executor)
}
pjp.proceed(Array(EssentialAction(essentialAction)))
}
@Before("call(* play.api.GlobalSettings.onError(..)) && args(request, ex)")
def beforeOnError(request: TraceContextAware, ex: Throwable): Unit = {
Tracer.currentContext.collect { ctx ⇒
recordHttpServerMetrics(InternalServerError.header, ctx.name)
}
}
def recordHttpServerMetrics(header: ResponseHeader, traceName: String): Unit =
Kamon(Play).httpServerMetrics.recordResponse(traceName, header.status.toString)
def storeDiagnosticData(request: RequestHeader): Unit = {
val agent = request.headers.get(UserAgent).getOrElse(Unknown)
val forwarded = request.headers.get(XForwardedFor).getOrElse(Unknown)
TraceLocal.store(HttpContextKey)(HttpContext(agent, request.uri, forwarded))
}
}
object RequestInstrumentation {
import kamon.util.TriemapAtomicGetOrElseUpdate.Syntax
import java.util.Locale
import scala.collection.concurrent.TrieMap
val UserAgent = "User-Agent"
val XForwardedFor = "X-Forwarded-For"
val Unknown = "unknown"
private val cache = TrieMap.empty[String, String]
private val normalizePattern = """\$([^<]+)<[^>]+>""".r
def normaliseTraceName(requestHeader: RequestHeader): Option[String] = requestHeader.tags.get(Routes.ROUTE_VERB).map({ verb ⇒
val path = requestHeader.tags(Routes.ROUTE_PATTERN)
cache.atomicGetOrElseUpdate(s"$verb$path", {
val traceName = {
// Convert paths of form GET /foo/bar/$paramname<regexp>/blah to foo.bar.paramname.blah.get
val p = normalizePattern.replaceAllIn(path, "$1").replace('/', '.').dropWhile(_ == '.')
val normalisedPath = {
if (p.lastOption.filter(_ != '.').isDefined) s"$p."
else p
}
s"$normalisedPath${verb.toLowerCase(Locale.ENGLISH)}"
}
traceName
})
})
}
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