handle global registry version loading more than once (with different versions)

Author: Han Kang

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

@@ -74,7 +74,7 @@ func TestCounter(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			registry := NewKubeRegistry(&apimachineryversion.Info{
+			registry := NewKubeRegistry(apimachineryversion.Info{
 				Major:      "1",
 				Minor:      "15",
 				GitVersion: "v1.15.0-alpha-1.12345",
@@ -175,7 +175,7 @@ func TestCounterVec(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			registry := NewKubeRegistry(&apimachineryversion.Info{
+			registry := NewKubeRegistry(apimachineryversion.Info{
 				Major:      "1",
 				Minor:      "15",
 				GitVersion: "v1.15.0-alpha-1.12345",

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

@@ -17,6 +17,7 @@ limitations under the License.
 package legacyregistry
 
 import (
+	"fmt"
 	apimachineryversion "k8s.io/apimachinery/pkg/version"
 	"k8s.io/component-base/metrics"
 	"sync"
@@ -38,15 +39,20 @@ type metricsRegistryFactory struct {
 // SetRegistryFactoryVersion sets the kubernetes version information for all
 // subsequent metrics registry initializations. Only the first call has an effect.
 // If a version is not set, then metrics registry creation will no-opt
-func SetRegistryFactoryVersion(ver *apimachineryversion.Info) []error {
+func SetRegistryFactoryVersion(ver apimachineryversion.Info) []error {
 	globalRegistryFactory.registrationLock.Lock()
 	defer globalRegistryFactory.registrationLock.Unlock()
 	if globalRegistryFactory.kubeVersion != nil {
+		if globalRegistryFactory.kubeVersion.String() != ver.String() {
+			panic(fmt.Sprintf("Cannot load a global registry more than once, had %s tried to load %s",
+				globalRegistryFactory.kubeVersion.String(),
+				ver.String()))
+		}
 		return nil
 	}
 	registrationErrs := make([]error, 0)
 	globalRegistryFactory.globalRegistry = metrics.NewKubeRegistry(ver)
-	globalRegistryFactory.kubeVersion = ver
+	globalRegistryFactory.kubeVersion = &ver
 	for _, c := range globalRegistryFactory.registerQueue {
 		err := globalRegistryFactory.globalRegistry.Register(c)
 		if err != nil {

staging/src/k8s.io/component-base/metrics/legacyregistry/registry_test.go

@@ -27,7 +27,7 @@ import (
 )
 
 func init() {
-	SetRegistryFactoryVersion(&apimachineryversion.Info{
+	SetRegistryFactoryVersion(apimachineryversion.Info{
 		Major:      "1",
 		Minor:      "15",
 		GitVersion: "v1.15.0-alpha-1.12345",
@@ -161,7 +161,7 @@ func TestDeferredRegister(t *testing.T) {
 		t.Errorf("Got err == %v, expected no error", err)
 	}
 	// set the global registry version
-	errs := SetRegistryFactoryVersion(&apimachineryversion.Info{
+	errs := SetRegistryFactoryVersion(apimachineryversion.Info{
 		Major:      "1",
 		Minor:      "15",
 		GitVersion: "v1.15.0-alpha-1.12345",
@@ -185,7 +185,7 @@ func TestDeferredMustRegister(t *testing.T) {
 	MustRegister(alphaDeprecatedCounter)
 	assert.Panics(t,
 		func() {
-			SetRegistryFactoryVersion(&apimachineryversion.Info{
+			SetRegistryFactoryVersion(apimachineryversion.Info{
 				Major:      "1",
 				Minor:      "15",
 				GitVersion: "v1.15.0-alpha-1.12345",

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

@@ -88,9 +88,9 @@ func (kr *kubeRegistry) Gather() ([]*dto.MetricFamily, error) {
 
 // NewKubeRegistry creates a new vanilla Registry without any Collectors
 // pre-registered.
-func NewKubeRegistry(v *apimachineryversion.Info) KubeRegistry {
+func NewKubeRegistry(v apimachineryversion.Info) KubeRegistry {
 	return &kubeRegistry{
 		PromRegistry: prometheus.NewRegistry(),
-		version:      parseVersion(*v),
+		version:      parseVersion(v),
 	}
 }

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

@@ -108,7 +108,7 @@ func TestRegister(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			registry := NewKubeRegistry(&apimachineryversion.Info{
+			registry := NewKubeRegistry(apimachineryversion.Info{
 				Major:      "1",
 				Minor:      "15",
 				GitVersion: "v1.15.0-alpha-1.12345",
@@ -179,7 +179,7 @@ func TestMustRegister(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.desc, func(t *testing.T) {
-			registry := NewKubeRegistry(&apimachineryversion.Info{
+			registry := NewKubeRegistry(apimachineryversion.Info{
 				Major:      "1",
 				Minor:      "15",
 				GitVersion: "v1.15.0-alpha-1.12345",