1 files changed, 88 insertions, 2 deletions

diff --git a/kamon-core/src/main/scala/kamon/status/Status.scala b/kamon-core/src/main/scala/kamon/status/Status.scala
index dc059277..2a52b95f 100644
--- a/kamon-core/src/main/scala/kamon/status/Status.scala
+++ b/kamon-core/src/main/scala/kamon/status/Status.scala
@@ -6,23 +6,50 @@ import kamon.metric.MetricRegistry
 import kamon.{Configuration, Environment, Kamon}
 import kamon.module.ModuleRegistry
 import kamon.module.Module.{Kind => ModuleKind}
+import java.util.{Collections, Map => JavaMap, List => JavaList}
 
 /**
-  * Allows accessing of component's status APIs without exposing any other internal API from those components.
+  * Exposes Kamon components' status information. This is meant to be used for informational and debugging purposes.
   */
 class Status(_moduleRegistry: ModuleRegistry, _metricRegistry: MetricRegistry, configuration: Configuration) {
 
+  /**
+    * Settings currently used by Kamon.
+    */
   def settings(): Status.Settings =
     Status.Settings(BuildInfo.version, Kamon.environment, configuration.config())
 
   /**
-    * Information about what modules have been detected in the classpath and their current status.
+    * Status of the module registry. Describes what modules have been detected in the classpath and their current
+    * statuses.
     */
   def moduleRegistry(): Status.ModuleRegistry =
     _moduleRegistry.status()
 
+  /**
+    * Status of the metric registry. Describes all metrics currently tracked by Kamon.
+    */
   def metricRegistry(): Status.MetricRegistry =
     _metricRegistry.status()
+
+
+  /**
+    * PRIVATE API.
+    *
+    * Status of instrumentation modules that have been detected and/or loaded into the current JVM. This
+    * API is not meant to be used by the general public.
+    *
+    * Read the [[Status.Instrumentation]] companion object's docs for more information.
+    */
+  private[kamon] def instrumentation(): Status.Instrumentation = {
+    import Status.Instrumentation._
+
+    Status.Instrumentation(
+      isActive(),
+      modules(),
+      errors()
+    )
+  }
 }
 
 
@@ -57,4 +84,63 @@ object Status {
     tags: Map[String, String],
     instrumentType: InstrumentType
   )
+
+
+  /**
+    * Status of the instrumentation modules. This data is completely untyped and not expected to be used anywhere
+    * outside Kamon.
+    */
+  private[kamon] case class Instrumentation(
+    isIActive: Boolean,
+    modules: JavaMap[String, String],
+    errors: JavaMap[String, JavaList[Throwable]]
+  )
+
+
+  /**
+    * This object works as a bridge between Kamon and Kanela to gather information about instrumentation modules. When
+    * instrumentation is enabled, it should replace the implementation of the members of this object and return proper
+    * information.
+    *
+    * This data is only exposed directly to the status page API because it lacks any sort of type safety. We might
+    * change this in the future and provide proper types for all instrumentation modules' info.
+    */
+  private[kamon] object Instrumentation {
+
+    /**
+      * Whether instrumentation is active or not. When Kanela is present it will replace this method to return true.
+      */
+    def isActive(): Boolean =
+      false
+
+    /**
+      * List all instrumentation modules known and their current status. The result map contains the module name as keys
+      * and a JSON representation of the module status as values. The expected structure in the JSON representations is
+      * as follows:
+      *
+      *   {
+      *     'description': 'A explicative module description',
+      *     'isEnabled': true | false,
+      *     'isActive': true | false
+      *   }
+      *
+      *  The "isEnabled" flag tells whether the module is able to instrument classes or not. By default, all modules are
+      *  able to instrument classes but some modules might be shipped in a disabled state or forced to be disabled via
+      *  configuration.
+      *
+      *  The "isActive" flag tells whether the modules has already applied instrumentation to any of its target classes.
+      *
+      */
+    def modules(): JavaMap[String, String] =
+      Collections.emptyMap()
+
+
+    /**
+      * List all errors that might have happened during the instrumentation initialization. The resulting map contains
+      * a list of modules and any exceptions thrown by them during initialization. If not exceptions are thrown the map
+      * will always be empty.
+      */
+    def errors(): JavaMap[String, JavaList[Throwable]] =
+      Collections.emptyMap()
+  }
 }