apply PR comments

Author: Yaroslav Derman

instrumentation/kamon-play/src/main/resources/reference.conf

@@ -107,6 +107,12 @@ kamon.instrumentation.play.http {
       # Custom mappings between routes and operation names.
       operations {
 
+        # Default configuration for HttpOperationNameGenerator implementation, but it has never been used
+        #   - default: Uses the set default operation name
+        #   - method: Uses the request HTTP method as the operation name.
+        #
+        name-generator = "default"
+
         # The default operation name to be used when creating Spans to handle the HTTP server requests. In most
         # cases it is not possible to define an operation name right at the moment of starting the HTTP server Span
         # and in those cases, this operation name will be initially assigned to the Span. Instrumentation authors
@@ -140,9 +146,29 @@ kamon.instrumentation.play.http {
       }
     }
 
-    name-generator = "kamon.instrumentation.play.DefaultRouterOperationNameGenerator"
+    #
+    # Configure specefic tracing/monitoring elements which depends on `play-framework` internal APIs that might change in the future
+    #
+    extra {
+      # Framework-specific way to generate operations names instead of using `kamon.instrumentation.play.http.server.tracing.operations.name-generator`
+      # Used by default with implementations that converts paths of form `/foo/bar/$paramname<regexp>/blah` to `/foo/bar/paramname/blah`
+      #
+      # FQCN for a kamon.instrumentation.play.RouterOperationNameGenerator implementation, or ony of the following shorthand forms:
+      #   - default: Uses the set default operation name
+      #   - method: Uses the request HTTP method as the operation name.
+      #
+      name-generator = "kamon.instrumentation.play.DefaultRouterOperationNameGenerator"
+
+      # Framework-specific way to generate operations names instead of using `kamon.instrumentation.play.http.server.tracing.operations.name-generator`
+      # Used by default with setting operation name to `request.uri.toRelative`
+      #
+      # FQCN for a kamon.instrumentation.play.GrpcRouterNameGenerator implementation, or ony of the following shorthand forms:
+      #   - default: Uses the set default operation name
+      #   - method: Uses the request HTTP method as the operation name.
+      #
+      grpc-name-generator = "kamon.instrumentation.play.DefaultGrpcRouterNameGenerator"
+    }
 
-    grpc-name-generator = "kamon.instrumentation.play.DefaultGrpcRouterNameGenerator"
   }
 
   client {

instrumentation/kamon-play/src/main/scala/kamon/instrumentation/play/PlayServerInstrumentation.scala

@@ -253,7 +253,7 @@ object GenerateOperationNameOnFilterHandler {
   Kamon.onReconfigure(newConfig => _routerNameGenerator = rebuildRouterNameGenerator(newConfig))
 
   private def rebuildRouterNameGenerator(config: Config): RouterOperationNameGenerator = {
-    val nameGeneratorClazz = config.getString("kamon.instrumentation.play.http.server.name-generator")
+    val nameGeneratorClazz = config.getString("kamon.instrumentation.play.http.server.extra.name-generator")
     Try(ClassLoading.createInstance[RouterOperationNameGenerator](nameGeneratorClazz)) match {
       case Failure(exception) =>
         _logger.error(s"Exception occurred on $nameGeneratorClazz instance creation, used default", exception)
@@ -284,7 +284,7 @@ object GenerateGRPCOperationName {
   Kamon.onReconfigure(newConfig => _grpcRouterNameGenerator = rebuildRouterNameGenerator(newConfig))
 
   private def rebuildRouterNameGenerator(config: Config): GrpcRouterNameGenerator = {
-    val nameGeneratorClazz = config.getString("kamon.instrumentation.play.http.server.grpc-name-generator")
+    val nameGeneratorClazz = config.getString("kamon.instrumentation.play.http.server.extra.grpc-name-generator")
     Try(ClassLoading.createInstance[GrpcRouterNameGenerator](nameGeneratorClazz)) match {
       case Failure(exception) =>
         _logger.error(s"Exception occurred on $nameGeneratorClazz instance creation, used default", exception)