add support for environment tags, fixes #510

2 files changed, 16 insertions, 3 deletions

diff --git a/kamon-core/src/main/resources/reference.conf b/kamon-core/src/main/resources/reference.conf
index 659114ca..b3fd3b17 100644
--- a/kamon-core/src/main/resources/reference.conf
+++ b/kamon-core/src/main/resources/reference.conf
@@ -11,6 +11,18 @@ kamon {
 
     # Identifier for a particular instance of this service. If set to `auto` Kamon will use the pattern service@host.
     instance = "auto"
+
+    # Arbitraty key-value pairs that further identify the environment where this service instance is running. Typically
+    # these tags will be used by the reporting modules as additional tags for all metrics or spans. Take a look at each
+    # reporter module's configuration to ensure these tags are supported and included in the reported data. Example:
+    #
+    # kamon.environment.tags {
+    #   env = "staging"
+    #   region = "us-east-1"
+    # }
+    tags {
+
+    }
   }
 
   # FQCN of the reporter instances that should be loaded when calling `Kamon.reporters.loadReportersFromConfig()`. All
diff --git a/kamon-core/src/main/scala/kamon/Environment.scala b/kamon-core/src/main/scala/kamon/Environment.scala
index 80833352..1c00679d 100644
--- a/kamon-core/src/main/scala/kamon/Environment.scala
+++ b/kamon-core/src/main/scala/kamon/Environment.scala
@@ -21,15 +21,16 @@ import java.util.concurrent.ThreadLocalRandom
 import com.typesafe.config.Config
 import kamon.util.HexCodec
 
-case class Environment(host: String, service: String, instance: String, incarnation: String)
+case class Environment(host: String, service: String, instance: String, incarnation: String, tags: Map[String, String])
 
 object Environment {
   private val incarnation = HexCodec.toLowerHex(ThreadLocalRandom.current().nextLong())
 
   def fromConfig(config: Config): Environment = {
     val environmentConfig = config.getConfig("kamon.environment")
-
     val service = environmentConfig.getString("service")
+    val tagsConfig = environmentConfig.getConfig("tags")
+    val tags = tagsConfig.topLevelKeys.map(tag => (tag -> tagsConfig.getString(tag))).toMap
 
     val host = readValueOrGenerate(
       environmentConfig.getString("host"),
@@ -41,7 +42,7 @@ object Environment {
       s"$service@$host"
     )
 
-    Environment(host, service, instance, incarnation)
+    Environment(host, service, instance, incarnation, tags)
   }
 
   private def readValueOrGenerate(configuredValue: String, generator: => String): String =