expose prometheus.Registerer so that we can hook into this from exter…

…nal sources

Change-Id: I0b4aa2218e309722a85143a50200e9e105020866

staging/src/k8s.io/component-base/metrics/registry.go

@@ -157,6 +157,10 @@ type KubeRegistry interface {
 	Reset()
 	// RegisterMetaMetrics registers metrics about the number of registered metrics.
 	RegisterMetaMetrics()
+	// Registerer exposes the underlying prometheus registerer
+	Registerer() prometheus.Registerer
+	// Gatherer exposes the underlying prometheus gatherer
+	Gatherer() prometheus.Gatherer
 }
 
 // kubeRegistry is a wrapper around a prometheus registry-type object. Upon initialization
@@ -188,6 +192,16 @@ func (kr *kubeRegistry) Register(c Registerable) error {
 	return nil
 }
 
+// Registerer exposes the underlying prometheus.Registerer
+func (kr *kubeRegistry) Registerer() prometheus.Registerer {
+	return kr.PromRegistry
+}
+
+// Gatherer exposes the underlying prometheus.Gatherer
+func (kr *kubeRegistry) Gatherer() prometheus.Gatherer {
+	return kr.PromRegistry
+}
+
 // MustRegister works like Register but registers any number of
 // Collectors and panics upon the first registration that causes an
 // error.