! newrelic: major refactor of the newrelic reporter

Most notable changes:
  - The agent connection setup is separated from the actual metrics reporting,
    this will be important in the near future when we start sending errors too.
  - The metrics subscriptions are delayed until the connection to the agent is
    established.
  - The Tick metrics buffer is only created if necessary.
  - Introduced the kamon.newrelic.max-initialize-retries and initialize-retry-delay
    settings.
  - External service calls via HTTP clients are reported as external services.

1 files changed, 33 insertions, 0 deletions

diff --git a/kamon-newrelic/src/main/scala/kamon/newrelic/CustomMetricExtractor.scala b/kamon-newrelic/src/main/scala/kamon/newrelic/CustomMetricExtractor.scala
new file mode 100644
index 00000000..84472593
--- /dev/null
+++ b/kamon-newrelic/src/main/scala/kamon/newrelic/CustomMetricExtractor.scala
@@ -0,0 +1,33 @@
+/*
+ * =========================================================================================
+ * 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 kamon.newrelic
+
+import kamon.metric.UserMetrics.UserMetricGroup
+import kamon.metric._
+import kamon.newrelic.Agent.Settings
+
+object CustomMetricExtractor extends MetricExtractor {
+
+  def extract(settings: Settings, collectionContext: CollectionContext, metrics: Map[MetricGroupIdentity, MetricGroupSnapshot]): Map[MetricID, MetricData] = {
+    metrics.collect {
+      case (mg: UserMetricGroup, groupSnapshot) ⇒
+        groupSnapshot.metrics collect {
+          case (name, snapshot) ⇒ Metric.fromKamonMetricSnapshot(snapshot, s"Custom/${mg.name}", None, Scale.Unit)
+        }
+    }.flatten.toMap
+  }
+}