add the EnvironmentTagBuilder utility class

1 files changed, 43 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/util/EnvironmentTagBuilder.scala b/kamon-core/src/main/scala/kamon/util/EnvironmentTagBuilder.scala
new file mode 100644
index 00000000..09e643e9
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/util/EnvironmentTagBuilder.scala
@@ -0,0 +1,43 @@
+package kamon.util
+
+import com.typesafe.config.Config
+import kamon.{Environment, Kamon}
+
+import scala.collection.JavaConverters._
+
+
+/**
+  *   Utility class to create a Map[String, String] encoding all the Environment information based on the provided
+  *   Config. The Config instance is expected to have the following members:
+  *
+  *     - service:          Boolean. If true a service tag is included.
+  *     - host:             Boolean. If true a host tag is included.
+  *     - instance:         Boolean. If true a instance tag is included.
+  *     - blacklisted-tags: List[String]. List of Environment tags that should not be included in the result.
+  *
+  *   This utility is meant to be used mostly by reporter modules.
+  *
+  */
+object EnvironmentTagBuilder {
+
+  def create(config: Config): Map[String, String] =
+    create(Kamon.environment, config)
+
+  def create(env: Environment, config: Config): Map[String, String] = {
+    val envTags = Map.newBuilder[String, String]
+
+    if(config.getBoolean("service"))
+      envTags += ("service" -> env.service)
+
+    if(config.getBoolean("host"))
+      envTags += ("host" -> env.host)
+
+    if(config.getBoolean("instance"))
+      envTags += ("instance" -> env.instance)
+
+    val blacklistedTags = config.getStringList("blacklisted-tags").asScala
+    env.tags.filterKeys(k => !blacklistedTags.contains(k)).foreach(p => envTags += p)
+
+    envTags.result()
+  }
+}