+ kamon-examples: updated play example to the latest version

3 files changed, 94 insertions, 0 deletions

diff --git a/kamon-examples/kamon-play-example/app/Global.scala b/kamon-examples/kamon-play-example/app/Global.scala
new file mode 100644
index 00000000..b7907560
--- /dev/null
+++ b/kamon-examples/kamon-play-example/app/Global.scala
@@ -0,0 +1,9 @@
+import filters.TraceLocalFilter
+import play.api.mvc.WithFilters
+
+object Global extends WithFilters(TraceLocalFilter){
+
+}
+
+
+
diff --git a/kamon-examples/kamon-play-example/app/controllers/KamonPlayExample.scala b/kamon-examples/kamon-play-example/app/controllers/KamonPlayExample.scala
new file mode 100644
index 00000000..e5fd78b0
--- /dev/null
+++ b/kamon-examples/kamon-play-example/app/controllers/KamonPlayExample.scala
@@ -0,0 +1,49 @@
+/* ===================================================
+ * 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 controllers
+
+import play.api.Logger
+import play.api.libs.concurrent.Execution.Implicits.defaultContext
+import play.api.mvc.{Action, Controller}
+
+import scala.concurrent._
+
+/*
+
+curl -i -H 'X-Trace-Token:kamon-test' -H 'MyTraceLocalStorageKey:extra-header' -X GET "http://localhost:9000/helloKamon"
+
+we should get:
+
+HTTP/1.1 200 OK
+Content-Type: text/plain; charset=utf-8
+MyTraceLocalStorageKey: extra-header -> Extra Information
+X-Trace-Token: kamon-test -> default Trace-Token
+Content-Length: 18
+
+Say hello to Kamon
+
+ */
+object KamonPlayExample extends Controller {
+
+  val logger = Logger(this.getClass)
+
+  def sayHelloKamon() = Action.async {
+    Future {
+      logger.info("Say hello to Kamon")
+      Ok("Say hello to Kamon")
+    }
+  }
+}
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..c9600fad
--- /dev/null
+++ b/kamon-examples/kamon-play-example/app/filters/TraceLocalFilter.scala
@@ -0,0 +1,36 @@
+package filters
+
+import kamon.trace.{TraceRecorder, TraceLocal}
+import play.api.Logger
+import play.api.mvc.{Result, RequestHeader, Filter}
+import play.api.libs.concurrent.Execution.Implicits.defaultContext
+import scala.concurrent.Future
+
+object TraceLocalKey extends TraceLocal.TraceLocalKey {
+  type ValueType = String
+}
+
+/*
+ By default Kamon spreads the trace-token-header-name but sometimes is necessary pass through the application requests with some infomation like
+ extra headers, with kamon it's possible using 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 used 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"
+
+  override def apply(next: (RequestHeader) ⇒ Future[Result])(header: RequestHeader): Future[Result] = {
+    TraceRecorder.withTraceContext(TraceRecorder.currentContext) {
+
+      TraceLocal.store(TraceLocalKey)(header.headers.get(TraceLocalStorageKey).getOrElse("unknown"))
+
+      next(header).map {
+        val traceTokenValue = TraceLocal.retrieve(TraceLocalKey).getOrElse("unknown")
+        logger.info(s"traceTokenValue: $traceTokenValue")
+        result ⇒ result.withHeaders((TraceLocalStorageKey -> traceTokenValue))
+      }
+    }
+  }
+}