From 12a4ee235ff5e6528acd50274ae7facc276174ed Mon Sep 17 00:00:00 2001
From: Han Kang <hankang@google.com>
Date: Thu, 8 Aug 2019 13:39:29 -0700
Subject: [PATCH] expose ability to register native prometheus collectors

---
 .../metrics/legacyregistry/registry.go        | 13 ++++---
 .../k8s.io/component-base/metrics/registry.go | 37 +++++++++++--------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/staging/src/k8s.io/component-base/metrics/legacyregistry/registry.go b/staging/src/k8s.io/component-base/metrics/legacyregistry/registry.go
index 521ded64e9e..32595ed31a9 100644
--- a/staging/src/k8s.io/component-base/metrics/legacyregistry/registry.go
+++ b/staging/src/k8s.io/component-base/metrics/legacyregistry/registry.go
@@ -40,10 +40,12 @@ var (
 
 type noopRegistry struct{}
 
-func (noopRegistry) Register(metrics.Registerable) error  { return nil }
-func (noopRegistry) MustRegister(...metrics.Registerable) {}
-func (noopRegistry) Unregister(metrics.Registerable) bool { return true }
-func (noopRegistry) Gather() ([]*dto.MetricFamily, error) { return nil, nil }
+func (noopRegistry) Register(metrics.Registerable) error     { return nil }
+func (noopRegistry) MustRegister(...metrics.Registerable)    {}
+func (noopRegistry) RawRegister(prometheus.Collector) error  { return nil }
+func (noopRegistry) RawMustRegister(...prometheus.Collector) {}
+func (noopRegistry) Unregister(metrics.Registerable) bool    { return true }
+func (noopRegistry) Gather() ([]*dto.MetricFamily, error)    { return nil, nil }
 
 type metricsRegistryFactory struct {
 	globalRegistry    metrics.KubeRegistry
@@ -79,7 +81,8 @@ func SetRegistryFactoryVersion(ver apimachineryversion.Info) []error {
 		prometheus.NewGoCollector(),
 		prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}),
 	}
-	globalRegistryFactory.globalRegistry = metrics.NewPreloadedKubeRegistry(ver, preloadedMetrics...)
+	globalRegistryFactory.globalRegistry = metrics.NewKubeRegistry(ver)
+	globalRegistryFactory.globalRegistry.RawMustRegister(preloadedMetrics...)
 	globalRegistryFactory.kubeVersion = &ver
 	for _, c := range globalRegistryFactory.registerQueue {
 		err := globalRegistryFactory.globalRegistry.Register(c)
diff --git a/staging/src/k8s.io/component-base/metrics/registry.go b/staging/src/k8s.io/component-base/metrics/registry.go
index 237ef69c92f..b9c7eabbbee 100644
--- a/staging/src/k8s.io/component-base/metrics/registry.go
+++ b/staging/src/k8s.io/component-base/metrics/registry.go
@@ -57,6 +57,10 @@ type Registerable interface {
 // KubeRegistry is an interface which implements a subset of prometheus.Registerer and
 // prometheus.Gatherer interfaces
 type KubeRegistry interface {
+	// Deprecated
+	RawRegister(prometheus.Collector) error
+	// Deprecated
+	RawMustRegister(...prometheus.Collector)
 	Register(Registerable) error
 	MustRegister(...Registerable)
 	Unregister(Registerable) bool
@@ -96,6 +100,24 @@ func (kr *kubeRegistry) MustRegister(cs ...Registerable) {
 	kr.PromRegistry.MustRegister(metrics...)
 }
 
+// RawRegister takes a native prometheus.Collector and registers the collector
+// to the registry. This bypasses metrics safety checks, so should only be used
+// to register custom prometheus collectors.
+//
+// Deprecated
+func (kr *kubeRegistry) RawRegister(c prometheus.Collector) error {
+	return kr.PromRegistry.Register(c)
+}
+
+// RawMustRegister takes a native prometheus.Collector and registers the collector
+// to the registry. This bypasses metrics safety checks, so should only be used
+// to register custom prometheus collectors.
+//
+// Deprecated
+func (kr *kubeRegistry) RawMustRegister(cs ...prometheus.Collector) {
+	kr.PromRegistry.MustRegister(cs...)
+}
+
 // Unregister unregisters the Collector that equals the Collector passed
 // in as an argument.  (Two Collectors are considered equal if their
 // Describe method yields the same set of descriptors.) The function
@@ -125,18 +147,3 @@ func NewKubeRegistry(v apimachineryversion.Info) KubeRegistry {
 		version:      parseVersion(v),
 	}
 }
-
-// NewPreloadedKubeRegistry creates a new Registry with preloaded prometheus collectors
-// already registered. This is exposed specifically to maintain backwards
-// compatibility with the global prometheus registry.
-//
-// Deprecated
-func NewPreloadedKubeRegistry(v apimachineryversion.Info, cs ...prometheus.Collector) KubeRegistry {
-	registry := &kubeRegistry{
-		PromRegistry: prometheus.NewRegistry(),
-		version:      parseVersion(v),
-	}
-
-	registry.PromRegistry.MustRegister(cs...)
-	return registry
-}