aboutsummaryrefslogtreecommitdiff
path: root/kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala
diff options
context:
space:
mode:
Diffstat (limited to 'kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala')
-rw-r--r--kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala60
1 files changed, 60 insertions, 0 deletions
diff --git a/kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala b/kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala
new file mode 100644
index 00000000..c745e7ff
--- /dev/null
+++ b/kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala
@@ -0,0 +1,60 @@
+/* ===================================================
+ * 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 filters
+
+import kamon.trace.TraceLocal
+import kamon.trace.TraceLocal.{AvailableToMdc, TraceLocalKey}
+import play.api.Logger
+import play.api.mvc.{Result, RequestHeader, Filter}
+import play.api.libs.concurrent.Execution.Implicits.defaultContext
+import scala.concurrent.Future
+
+case class TraceLocalContainer(traceToken:String, importantHeader:String)
+
+object TraceLocalKey extends TraceLocal.TraceLocalKey[TraceLocalContainer]
+
+/*
+ By default kamon spreads the trace-token-header-name, but sometimes is necessary pass through the application requests with some information like
+ extra headers, with kamon it's possible using the TraceLocalStorage, in Play applications we can do an Action Filter or using Action Composition,
+ in this example we are using a simple filter where given a Header store the value and then put the value in the result headers..
+
+ More detailed usage of TraceLocalStorage: https://github.com/kamon-io/Kamon/blob/b17539d231da923ea854c01d2c69eb02ef1e85b1/kamon-core/src/test/scala/kamon/trace/TraceLocalSpec.scala
+ */
+object TraceLocalFilter extends Filter {
+ val logger = Logger(this.getClass)
+ val TraceLocalStorageKey = "MyTraceLocalStorageKey"
+
+ val userAgentHeader = "User-Agent"
+
+ //this value will be available in the MDC at the moment to call to Logger.*()s
+ val UserAgentHeaderAvailableToMDC = AvailableToMdc(userAgentHeader)
+
+ override def apply(next: (RequestHeader) ⇒ Future[Result])(header: RequestHeader): Future[Result] = {
+
+ def onResult(result:Result) = {
+ val traceLocalContainer = TraceLocal.retrieve(TraceLocalKey).getOrElse(TraceLocalContainer("unknown","unknown"))
+ result.withHeaders((TraceLocalStorageKey -> traceLocalContainer.traceToken))
+ }
+
+ //update the TraceLocalStorage
+ TraceLocal.store(TraceLocalKey)(TraceLocalContainer(header.headers.get(TraceLocalStorageKey).getOrElse("unknown"), "unknown"))
+ TraceLocal.store(UserAgentHeaderAvailableToMDC)(header.headers.get(userAgentHeader).getOrElse("unknown"))
+
+ //call the action
+ next(header).map(onResult)
+ }
+}