Fix admission metrics to track mutating/validating correctly

plugin/pkg/admission/namespace/autoprovision/admission_test.go

@@ -129,7 +129,6 @@ func TestAdmissionNamespaceExists(t *testing.T) {
 
 // TestIgnoreAdmission validates that a request is ignored if its not a create
 func TestIgnoreAdmission(t *testing.T) {
-	namespace := "test"
 	mockClient := newMockClientForTest([]string{})
 	handler, informerFactory, err := newHandlerForTest(mockClient)
 	if err != nil {

plugin/pkg/admission/persistentvolume/label/admission_test.go

@@ -77,7 +77,8 @@ func mockVolumeLabels(labels map[string]string) *mockVolumes {
 
 // TestAdmission
 func TestAdmission(t *testing.T) {
-	handler := NewPersistentVolumeLabel()
+	pvHandler := NewPersistentVolumeLabel()
+	handler := admission.NewChainHandler(admission.NewNamedHandler("pv", pvHandler))
 	ignoredPV := api.PersistentVolume{
 		ObjectMeta: metav1.ObjectMeta{Name: "noncloud", Namespace: "myns"},
 		Spec: api.PersistentVolumeSpec{
@@ -100,8 +101,9 @@ func TestAdmission(t *testing.T) {
 	}
 
 	// Non-cloud PVs are ignored
-	if handler.Handles(admission.Delete) {
-		t.Errorf("Expected to only handle create")
+	err := handler.Admit(admission.NewAttributesRecord(&ignoredPV, nil, api.Kind("PersistentVolume").WithVersion("version"), ignoredPV.Namespace, ignoredPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
+	if err != nil {
+		t.Errorf("Unexpected error returned from admission handler (on ignored pv): %v", err)
 	}
 
 	// We only add labels on creation
@@ -111,7 +113,7 @@ func TestAdmission(t *testing.T) {
 	}
 
 	// Errors from the cloudprovider block creation of the volume
-	handler.ebsVolumes = mockVolumeFailure(fmt.Errorf("invalid volume"))
+	pvHandler.ebsVolumes = mockVolumeFailure(fmt.Errorf("invalid volume"))
 	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
 	if err == nil {
 		t.Errorf("Expected error when aws pv info fails")
@@ -119,7 +121,7 @@ func TestAdmission(t *testing.T) {
 
 	// Don't add labels if the cloudprovider doesn't return any
 	labels := make(map[string]string)
-	handler.ebsVolumes = mockVolumeLabels(labels)
+	pvHandler.ebsVolumes = mockVolumeLabels(labels)
 	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
 	if err != nil {
 		t.Errorf("Expected no error when creating aws pv")
@@ -129,7 +131,7 @@ func TestAdmission(t *testing.T) {
 	}
 
 	// Don't panic if the cloudprovider returns nil, nil
-	handler.ebsVolumes = mockVolumeFailure(nil)
+	pvHandler.ebsVolumes = mockVolumeFailure(nil)
 	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
 	if err != nil {
 		t.Errorf("Expected no error when cloud provider returns empty labels")
@@ -139,7 +141,7 @@ func TestAdmission(t *testing.T) {
 	labels = make(map[string]string)
 	labels["a"] = "1"
 	labels["b"] = "2"
-	handler.ebsVolumes = mockVolumeLabels(labels)
+	pvHandler.ebsVolumes = mockVolumeLabels(labels)
 	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
 	if err != nil {
 		t.Errorf("Expected no error when creating aws pv")

staging/src/k8s.io/apiserver/pkg/admission/BUILD

@@ -21,9 +21,8 @@ go_test(
     deps = [
         "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
         "//vendor/github.com/prometheus/client_model/go:go_default_library",
-        "//vendor/github.com/stretchr/testify/assert:go_default_library",
-        "//vendor/github.com/stretchr/testify/require:go_default_library",
         "//vendor/k8s.io/api/admissionregistration/v1alpha1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/apis/apiserver:go_default_library",

staging/src/k8s.io/apiserver/pkg/admission/chain.go

@@ -27,6 +27,13 @@ func NewChainHandler(handlers ...NamedHandler) chainAdmissionHandler {
 	return chainAdmissionHandler(handlers)
 }
 
+func NewNamedHandler(name string, i Interface) NamedHandler {
+	return &pluginHandler{
+		i:    i,
+		name: name,
+	}
+}
+
 const (
 	stepValidating = "validating"
 	stepMutating   = "mutating"
@@ -34,20 +41,21 @@ const (
 
 // Admit performs an admission control check using a chain of handlers, and returns immediately on first error
 func (admissionHandler chainAdmissionHandler) Admit(a Attributes) error {
-	var err error
 	start := time.Now()
-	defer func() {
-		Metrics.ObserveAdmissionStep(time.Since(start), err != nil, a, stepMutating)
-	}()
+	err := admissionHandler.admit(a)
+	Metrics.ObserveAdmissionStep(time.Since(start), err != nil, a, stepMutating)
+	return err
+}
 
+func (admissionHandler chainAdmissionHandler) admit(a Attributes) error {
 	for _, handler := range admissionHandler {
-		if !handler.Handles(a.GetOperation()) {
+		if !handler.Interface().Handles(a.GetOperation()) {
 			continue
 		}
-		if mutator, ok := handler.(MutationInterface); ok {
+		if mutator, ok := handler.Interface().(MutationInterface); ok {
 			t := time.Now()
-			err = mutator.Admit(a)
-			Metrics.ObserveAdmissionController(time.Since(t), err != nil, handler, a)
+			err := mutator.Admit(a)
+			Metrics.ObserveAdmissionController(time.Since(t), err != nil, handler, a, stepMutating)
 			if err != nil {
 				return err
 			}
@@ -58,20 +66,21 @@ func (admissionHandler chainAdmissionHandler) Admit(a Attributes) error {
 
 // Validate performs an admission control check using a chain of handlers, and returns immediately on first error
 func (admissionHandler chainAdmissionHandler) Validate(a Attributes) error {
-	var err error
 	start := time.Now()
-	defer func() {
-		Metrics.ObserveAdmissionStep(time.Since(start), err != nil, a, stepValidating)
-	}()
+	err := admissionHandler.validate(a)
+	Metrics.ObserveAdmissionStep(time.Since(start), err != nil, a, stepValidating)
+	return err
+}
 
+func (admissionHandler chainAdmissionHandler) validate(a Attributes) (err error) {
 	for _, handler := range admissionHandler {
-		if !handler.Handles(a.GetOperation()) {
+		if !handler.Interface().Handles(a.GetOperation()) {
 			continue
 		}
-		if validator, ok := handler.(ValidationInterface); ok {
+		if validator, ok := handler.Interface().(ValidationInterface); ok {
 			t := time.Now()
-			err = validator.Validate(a)
-			Metrics.ObserveAdmissionController(time.Since(t), err != nil, handler, a)
+			err := validator.Validate(a)
+			Metrics.ObserveAdmissionController(time.Since(t), err != nil, handler, a, stepValidating)
 			if err != nil {
 				return err
 			}
@@ -83,7 +92,7 @@ func (admissionHandler chainAdmissionHandler) Validate(a Attributes) error {
 // Handles will return true if any of the handlers handles the given operation
 func (admissionHandler chainAdmissionHandler) Handles(operation Operation) bool {
 	for _, handler := range admissionHandler {
-		if handler.Handles(operation) {
+		if handler.Interface().Handles(operation) {
 			return true
 		}
 	}

staging/src/k8s.io/apiserver/pkg/admission/chain_test.go

@@ -17,46 +17,15 @@ limitations under the License.
 package admission
 
 import (
-	"fmt"
+	"strconv"
 	"testing"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
-type FakeHandler struct {
-	*Handler
-	name                     string
-	admit, admitCalled       bool
-	validate, validateCalled bool
-}
-
-func (h *FakeHandler) Admit(a Attributes) (err error) {
-	h.admitCalled = true
-	if h.admit {
-		return nil
-	}
-	return fmt.Errorf("Don't admit")
-}
-
-func (h *FakeHandler) Validate(a Attributes) (err error) {
-	h.validateCalled = true
-	if h.validate {
-		return nil
-	}
-	return fmt.Errorf("Don't validate")
-}
-
-func makeHandler(name string, accept bool, ops ...Operation) Interface {
-	return &FakeHandler{
-		name:     name,
-		admit:    accept,
-		validate: accept,
-		Handler:  NewHandler(ops...),
-	}
-}
-
 func TestAdmitAndValidate(t *testing.T) {
-	sysns := "kube-system"
+	sysns := metav1.NamespaceSystem
 	otherns := "default"
 	tests := []struct {
 		name      string
@@ -64,7 +33,6 @@ func TestAdmitAndValidate(t *testing.T) {
 		operation Operation
 		chain     chainAdmissionHandler
 		accept    bool
-		reject    bool
 		calls     map[string]bool
 	}{
 		{
@@ -72,9 +40,9 @@ func TestAdmitAndValidate(t *testing.T) {
 			ns:        sysns,
 			operation: Create,
 			chain: []NamedHandler{
-				makeHandler("a", true, Update, Delete, Create),
-				makeHandler("b", true, Delete, Create),
-				makeHandler("c", true, Create),
+				makeNamedHandler("a", true, Update, Delete, Create),
+				makeNamedHandler("b", true, Delete, Create),
+				makeNamedHandler("c", true, Create),
 			},
 			calls:  map[string]bool{"a": true, "b": true, "c": true},
 			accept: true,
@@ -84,9 +52,9 @@ func TestAdmitAndValidate(t *testing.T) {
 			ns:        otherns,
 			operation: Create,
 			chain: []NamedHandler{
-				makeHandler("a", true, Update, Delete, Create),
-				makeHandler("b", false, Delete),
-				makeHandler("c", true, Create),
+				makeNamedHandler("a", true, Update, Delete, Create),
+				makeNamedHandler("b", false, Delete),
+				makeNamedHandler("c", true, Create),
 			},
 			calls:  map[string]bool{"a": true, "c": true},
 			accept: true,
@@ -96,9 +64,9 @@ func TestAdmitAndValidate(t *testing.T) {
 			ns:        sysns,
 			operation: Connect,
 			chain: []NamedHandler{
-				makeHandler("a", true, Update, Delete, Create),
-				makeHandler("b", false, Delete),
-				makeHandler("c", true, Create),
+				makeNamedHandler("a", true, Update, Delete, Create),
+				makeNamedHandler("b", false, Delete),
+				makeNamedHandler("c", true, Create),
 			},
 			calls:  map[string]bool{},
 			accept: true,
@@ -108,77 +76,112 @@ func TestAdmitAndValidate(t *testing.T) {
 			ns:        otherns,
 			operation: Delete,
 			chain: []NamedHandler{
-				makeHandler("a", true, Update, Delete, Create),
-				makeHandler("b", false, Delete),
-				makeHandler("c", true, Create),
+				makeNamedHandler("a", true, Update, Delete, Create),
+				makeNamedHandler("b", false, Delete),
+				makeNamedHandler("c", true, Create),
 			},
 			calls:  map[string]bool{"a": true, "b": true},
 			accept: false,
-			reject: true,
 		},
 	}
 	for _, test := range tests {
 		Metrics.reset()
 		t.Logf("testcase = %s", test.name)
 		// call admit and check that validate was not called at all
-		err = test.chain.Admit(NewAttributesRecord(nil, nil, schema.GroupVersionKind{}, "", "", schema.GroupVersionResource{}, "", test.operation, nil))
+		err := test.chain.Admit(NewAttributesRecord(nil, nil, schema.GroupVersionKind{}, test.ns, "", schema.GroupVersionResource{}, "", test.operation, nil))
 		accepted := (err == nil)
 		if accepted != test.accept {
 			t.Errorf("unexpected result of admit call: %v", accepted)
 		}
 		for _, h := range test.chain {
-			fake := h.(*FakeHandler)
-			_, shouldBeCalled := test.calls[fake.name]
+			fake := h.Interface().(*FakeHandler)
+			_, shouldBeCalled := test.calls[h.Name()]
 			if shouldBeCalled != fake.admitCalled {
-				t.Errorf("%s: admit handler %s not called as expected: %v", test.name, fake.name, fake.admitCalled)
+				t.Errorf("admit handler %s not called as expected: %v", h.Name(), fake.admitCalled)
 				continue
 			}
 			if fake.validateCalled {
-				t.Errorf("%s: validate handler %s called during admit", test.name, fake.name)
+				t.Errorf("validate handler %s called during admit", h.Name())
 			}
 
-			// reset value for validation test
+			//  reset value for validation test
 			fake.admitCalled = false
 		}
 
+		labelFilter := map[string]string{
+			"is_system_ns": strconv.FormatBool(test.ns == sysns),
+			"type":         "mutating",
+		}
+
+		checkAdmitAndValidateMetrics(t, labelFilter, test.accept, test.calls)
+		Metrics.reset()
 		// call validate and check that admit was not called at all
-		err = test.chain.Validate(NewAttributesRecord(nil, nil, schema.GroupVersionKind{}, "", "", schema.GroupVersionResource{}, "", test.operation, nil))
+		err = test.chain.Validate(NewAttributesRecord(nil, nil, schema.GroupVersionKind{}, test.ns, "", schema.GroupVersionResource{}, "", test.operation, nil))
 		accepted = (err == nil)
 		if accepted != test.accept {
-			t.Errorf("%s: unexpected result of validate call: %v\n", test.name, accepted)
+			t.Errorf("unexpected result of validate call: %v\n", accepted)
 		}
 		for _, h := range test.chain {
-			fake := h.(*FakeHandler)
-			_, shouldBeCalled := test.calls[fake.name]
+			fake := h.Interface().(*FakeHandler)
+
+			_, shouldBeCalled := test.calls[h.Name()]
 			if shouldBeCalled != fake.validateCalled {
-				t.Errorf("%s: validate handler %s not called as expected: %v", test.name, fake.name, fake.validateCalled)
+				t.Errorf("validate handler %s not called as expected: %v", h.Name(), fake.validateCalled)
 				continue
 			}
 
 			if fake.admitCalled {
-				t.Errorf("%s: admit handler %s called during admit", test.name, fake.name)
+				t.Errorf("mutating handler unexpectedly called: %s", h.Name())
 			}
 		}
 
-		labels := metricLabels{
-			isSystemNs: test.ns == sysns,
-		}
-		if test.reject {
-			expectCountMetric(t, "apiserver_admission_step_rejected_total", labels, 1)
+		labelFilter = map[string]string{
+			"is_system_ns": strconv.FormatBool(test.ns == sysns),
+			"type":         "validating",
 		}
 
-		if test.accept {
-			expectCountMetric(t, "apiserver_admission_step_total", labels, 1)
-		}
+		checkAdmitAndValidateMetrics(t, labelFilter, test.accept, test.calls)
+	}
+}
 
+func checkAdmitAndValidateMetrics(t *testing.T, labelFilter map[string]string, accept bool, calls map[string]bool) {
+	acceptFilter := map[string]string{"rejected": "false"}
+	for k, v := range labelFilter {
+		acceptFilter[k] = v
+	}
+
+	rejectFilter := map[string]string{"rejected": "true"}
+	for k, v := range labelFilter {
+		rejectFilter[k] = v
+	}
+
+	if accept {
+		// Ensure exactly one admission end-to-end admission accept should have been recorded.
+		expectHistogramCountTotal(t, "apiserver_admission_step_latencies", acceptFilter, 1)
+
+		// Ensure the expected count of admission controllers have been executed.
+		expectHistogramCountTotal(t, "apiserver_admission_controller_latencies", acceptFilter, len(calls))
+	} else {
+		// When not accepted, ensure exactly one end-to-end rejection has been recorded.
+		expectHistogramCountTotal(t, "apiserver_admission_step_latencies", rejectFilter, 1)
+		if len(calls) > 0 {
+			if len(calls) > 1 {
+				// When not accepted, ensure that all but the last controller had been accepted, since
+				// the chain stops execution at the first rejection.
+				expectHistogramCountTotal(t, "apiserver_admission_controller_latencies", acceptFilter, len(calls)-1)
+			}
+
+			// When not accepted, ensure exactly one controller has been rejected.
+			expectHistogramCountTotal(t, "apiserver_admission_controller_latencies", rejectFilter, 1)
+		}
 	}
 }
 
 func TestHandles(t *testing.T) {
 	chain := chainAdmissionHandler{
-		makeHandler("a", true, Update, Delete, Create),
-		makeHandler("b", true, Delete, Create),
-		makeHandler("c", true, Create),
+		makeNamedHandler("a", true, Update, Delete, Create),
+		makeNamedHandler("b", true, Delete, Create),
+		makeNamedHandler("c", true, Create),
 	}
 
 	tests := []struct {

staging/src/k8s.io/apiserver/pkg/admission/metrics.go

@@ -34,33 +34,42 @@ const (
 )
 
 var (
-	latencyBuckets       = prometheus.ExponentialBuckets(10000, 2.0, 8)
+	latencyBuckets       = prometheus.ExponentialBuckets(25000, 2.0, 7)
 	latencySummaryMaxAge = 5 * time.Hour
 
+	// Metrics provides access to all admission metrics.
 	Metrics = newAdmissionMetrics()
 )
 
+// NamedHandler requires each admission.Interface be named, primarly for metrics tracking purposes.
+type NamedHandler interface {
+	Interface() Interface
+	Name() string
+}
+
+// AdmissionMetrics instruments admission with prometheus metrics.
 type AdmissionMetrics struct {
 	step            *metricSet
 	controller      *metricSet
 	externalWebhook *metricSet
 }
 
+// newAdmissionMetrics create a new AdmissionMetrics, configured with default metric names.
 func newAdmissionMetrics() *AdmissionMetrics {
 	// Admission metrics for a step of the admission flow. The entire admission flow is broken down into a series of steps
 	// Each step is identified by a distinct type label value.
-	step := newMetricSet("step_",
-		[]string{"operation", "group", "version", "resource", "subresource", "type", "is_system_ns"},
+	step := newMetricSet("step",
+		[]string{"type", "operation", "group", "version", "resource", "subresource", "is_system_ns", "rejected"},
 		"Admission sub-step %s, broken out for each operation and API resource and step type (validating or mutating).")
 
 	// Built-in admission controller metrics. Each admission controller is identified by name.
-	controller := newMetricSet("controller_",
-		[]string{"name", "type", "operation", "group", "version", "resource", "subresource", "is_system_ns"},
+	controller := newMetricSet("controller",
+		[]string{"name", "type", "operation", "group", "version", "resource", "subresource", "is_system_ns", "rejected"},
 		"Admission controller %s, identified by name and broken out for each operation and API resource and type (validating or mutating).")
 
 	// External admission webhook metrics. Each webhook is identified by name.
-	externalWebhook := newMetricSet("external_webhook_",
-		[]string{"name", "type", "operation", "group", "version", "resource", "subresource", "is_system_ns"},
+	externalWebhook := newMetricSet("external_webhook",
+		[]string{"name", "type", "operation", "group", "version", "resource", "subresource", "is_system_ns", "rejected"},
 		"External admission webhook %s, identified by name and broken out for each operation and API resource and type (validating or mutating).")
 
 	step.mustRegister()
@@ -75,30 +84,23 @@ func (m *AdmissionMetrics) reset() {
 	m.externalWebhook.reset()
 }
 
-// namedHandler requires each admission.Interface be named, primarly for metrics tracking purposes.
-type NamedHandler interface {
-	Interface
-	GetName() string
-}
-
 // ObserveAdmissionStep records admission related metrics for a admission step, identified by step type.
 func (m *AdmissionMetrics) ObserveAdmissionStep(elapsed time.Duration, rejected bool, attr Attributes, stepType string) {
 	gvr := attr.GetResource()
-	m.step.observe(elapsed, rejected, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), stepType, isSystemNsLabel(attr))
+	m.step.observe(elapsed, stepType, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), isSystemNsLabel(attr), strconv.FormatBool(rejected))
 }
 
 // ObserveAdmissionController records admission related metrics for a built-in admission controller, identified by it's plugin handler name.
-func (m *AdmissionMetrics) ObserveAdmissionController(elapsed time.Duration, rejected bool, handler NamedHandler, attr Attributes) {
-	t := typeToLabel(handler)
+func (m *AdmissionMetrics) ObserveAdmissionController(elapsed time.Duration, rejected bool, handler NamedHandler, attr Attributes, stepType string) {
 	gvr := attr.GetResource()
-	m.controller.observe(elapsed, rejected, handler.GetName(), t, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), isSystemNsLabel(attr))
+	m.controller.observe(elapsed, handler.Name(), stepType, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), isSystemNsLabel(attr), strconv.FormatBool(rejected))
 }
 
 // ObserveExternalWebhook records admission related metrics for a external admission webhook.
 func (m *AdmissionMetrics) ObserveExternalWebhook(elapsed time.Duration, rejected bool, hook *v1alpha1.ExternalAdmissionHook, attr Attributes) {
 	t := "validating" // TODO: pass in type (validating|mutating) once mutating webhook functionality has been implemented
 	gvr := attr.GetResource()
-	m.externalWebhook.observe(elapsed, rejected, hook.Name, t, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), isSystemNsLabel(attr))
+	m.externalWebhook.observe(elapsed, hook.Name, t, string(attr.GetOperation()), gvr.Group, gvr.Version, gvr.Resource, attr.GetSubresource(), isSystemNsLabel(attr), strconv.FormatBool(rejected))
 }
 
 // isSystemNsLabel returns the value to use for the `is_system_ns` metric label.
@@ -106,73 +108,18 @@ func isSystemNsLabel(a Attributes) string {
 	return strconv.FormatBool(a.GetNamespace() == metav1.NamespaceSystem)
 }
 
-func typeToLabel(i Interface) string {
-	switch i.(type) {
-	case MutationInterface:
-		return "mutating"
-	case ValidationInterface:
-		return "validating"
-	default:
-		return "UNRECOGNIZED_ADMISSION_TYPE"
-	}
-}
-
 type metricSet struct {
-	total            *prometheus.CounterVec
-	rejectedTotal    *prometheus.CounterVec
 	latencies        *prometheus.HistogramVec
 	latenciesSummary *prometheus.SummaryVec
 }
 
-func (m *metricSet) mustRegister() {
-	prometheus.MustRegister(m.total)
-	prometheus.MustRegister(m.rejectedTotal)
-	prometheus.MustRegister(m.latencies)
-	prometheus.MustRegister(m.latenciesSummary)
-}
-
-func (m *metricSet) reset() {
-	m.total.Reset()
-	m.rejectedTotal.Reset()
-	m.latencies.Reset()
-	m.latenciesSummary.Reset()
-}
-
-func (m *metricSet) observe(elapsed time.Duration, rejected bool, labels ...string) {
-	elapsedMicroseconds := float64(elapsed / time.Microsecond)
-	m.total.WithLabelValues(labels...).Inc()
-	if rejected {
-		m.rejectedTotal.WithLabelValues(labels...).Inc()
-	}
-	m.latencies.WithLabelValues(labels...).Observe(elapsedMicroseconds)
-	m.latenciesSummary.WithLabelValues(labels...).Observe(elapsedMicroseconds)
-}
-
 func newMetricSet(name string, labels []string, helpTemplate string) *metricSet {
 	return &metricSet{
-		total: prometheus.NewCounterVec(
-			prometheus.CounterOpts{
-				Namespace: namespace,
-				Subsystem: subsystem,
-				Name:      fmt.Sprintf("%stotal", name),
-				Help:      fmt.Sprintf(helpTemplate, "count"),
-			},
-			labels,
-		),
-		rejectedTotal: prometheus.NewCounterVec(
-			prometheus.CounterOpts{
-				Namespace: namespace,
-				Subsystem: subsystem,
-				Name:      fmt.Sprintf("%srejected_total", name),
-				Help:      fmt.Sprintf(helpTemplate, "rejected count"),
-			},
-			labels,
-		),
 		latencies: prometheus.NewHistogramVec(
 			prometheus.HistogramOpts{
 				Namespace: namespace,
 				Subsystem: subsystem,
-				Name:      fmt.Sprintf("%slatencies", name),
+				Name:      fmt.Sprintf("%s_latencies", name),
 				Help:      fmt.Sprintf(helpTemplate, "latency histogram"),
 				Buckets:   latencyBuckets,
 			},
@@ -182,7 +129,7 @@ func newMetricSet(name string, labels []string, helpTemplate string) *metricSet
 			prometheus.SummaryOpts{
 				Namespace: namespace,
 				Subsystem: subsystem,
-				Name:      fmt.Sprintf("%slatencies_summary", name),
+				Name:      fmt.Sprintf("%s_latencies_summary", name),
 				Help:      fmt.Sprintf(helpTemplate, "latency summary"),
 				MaxAge:    latencySummaryMaxAge,
 			},
@@ -190,3 +137,22 @@ func newMetricSet(name string, labels []string, helpTemplate string) *metricSet
 		),
 	}
 }
+
+// MustRegister registers all the prometheus metrics in the metricSet.
+func (m *metricSet) mustRegister() {
+	prometheus.MustRegister(m.latencies)
+	prometheus.MustRegister(m.latenciesSummary)
+}
+
+// Reset resets all the prometheus metrics in the metricSet.
+func (m *metricSet) reset() {
+	m.latencies.Reset()
+	m.latenciesSummary.Reset()
+}
+
+// Observe records an observed admission event to all metrics in the metricSet.
+func (m *metricSet) observe(elapsed time.Duration, labels ...string) {
+	elapsedMicroseconds := float64(elapsed / time.Microsecond)
+	m.latencies.WithLabelValues(labels...).Observe(elapsedMicroseconds)
+	m.latenciesSummary.WithLabelValues(labels...).Observe(elapsedMicroseconds)
+}

staging/src/k8s.io/apiserver/pkg/admission/metrics_test.go

@@ -34,48 +34,54 @@ var (
 func TestObserveAdmissionStep(t *testing.T) {
 	Metrics.reset()
 	Metrics.ObserveAdmissionStep(2*time.Second, false, attr, "mutating")
-	wantLabels := metricLabels{
-		operation:   string(Create),
-		group:       resource.Group,
-		version:     resource.Version,
-		resource:    resource.Resource,
-		subresource: "subresource",
-		tpe:         "mutating",
-		isSystemNs:  false,
+	wantLabels := map[string]string{
+		"operation":   string(Create),
+		"group":       resource.Group,
+		"version":     resource.Version,
+		"resource":    resource.Resource,
+		"subresource": "subresource",
+		"type":        "mutating",
+		"isSystemNs":  "false",
+		"rejected":    "false",
 	}
-	expectCountMetric(t, "apiserver_admission_step_total", wantLabels, 1)
+	expectHistogramCountTotal(t, "apiserver_admission_step_latencies", wantLabels, 1)
+	expectFindMetric(t, "apiserver_admission_step_latencies_summary", wantLabels)
 }
 
 func TestObserveAdmissionController(t *testing.T) {
 	Metrics.reset()
-	handler := makeHandler("a", true, Create)
-	Metrics.ObserveAdmissionController(2*time.Second, false, handler, attr)
-	wantLabels := metricLabels{
-		name:        "a",
-		operation:   string(Create),
-		group:       resource.Group,
-		version:     resource.Version,
-		resource:    resource.Resource,
-		subresource: "subresource",
-		tpe:         "mutating",
-		isSystemNs:  false,
+	handler := makeValidatingNamedHandler("a", true, Create)
+	Metrics.ObserveAdmissionController(2*time.Second, false, handler, attr, "validating")
+	wantLabels := map[string]string{
+		"name":        "a",
+		"operation":   string(Create),
+		"group":       resource.Group,
+		"version":     resource.Version,
+		"resource":    resource.Resource,
+		"subresource": "subresource",
+		"type":        "validating",
+		"isSystemNs":  "false",
+		"rejected":    "false",
 	}
-	expectCountMetric(t, "apiserver_admission_controller_total", wantLabels, 1)
+	expectHistogramCountTotal(t, "apiserver_admission_controller_latencies", wantLabels, 1)
+	expectFindMetric(t, "apiserver_admission_controller_latencies_summary", wantLabels)
 }
 
 func TestObserveExternalWebhook(t *testing.T) {
 	Metrics.reset()
 	hook := &v1alpha1.ExternalAdmissionHook{Name: "x"}
 	Metrics.ObserveExternalWebhook(2*time.Second, false, hook, attr)
-	wantLabels := metricLabels{
-		name:        "x",
-		operation:   string(Create),
-		group:       resource.Group,
-		version:     resource.Version,
-		resource:    resource.Resource,
-		subresource: "subresource",
-		tpe:         "validating",
-		isSystemNs:  false,
+	wantLabels := map[string]string{
+		"name":        "x",
+		"operation":   string(Create),
+		"group":       resource.Group,
+		"version":     resource.Version,
+		"resource":    resource.Resource,
+		"subresource": "subresource",
+		"type":        "validating",
+		"isSystemNs":  "false",
+		"rejected":    "false",
 	}
-	expectCountMetric(t, "apiserver_admission_external_webhook_total", wantLabels, 1)
+	expectHistogramCountTotal(t, "apiserver_admission_external_webhook_latencies", wantLabels, 1)
+	expectFindMetric(t, "apiserver_admission_external_webhook_latencies_summary", wantLabels)
 }

staging/src/k8s.io/apiserver/pkg/admission/plugins.go

@@ -41,11 +41,15 @@ type Plugins struct {
 
 // pluginHandler associates name with a admission.Interface handler.
 type pluginHandler struct {
-	Interface
+	i    Interface
 	name string
 }
 
-func (h *pluginHandler) GetName() string {
+func (h *pluginHandler) Interface() Interface {
+	return h.i
+}
+
+func (h *pluginHandler) Name() string {
 	return h.name
 }
 
@@ -143,7 +147,7 @@ func (ps *Plugins) NewFromPlugins(pluginNames []string, configProvider ConfigPro
 			return nil, err
 		}
 		if plugin != nil {
-			handler := &pluginHandler{Interface: plugin, name: pluginName}
+			handler := &pluginHandler{i: plugin, name: pluginName}
 			handlers = append(handlers, handler)
 		}
 	}

staging/src/k8s.io/apiserver/pkg/admission/testutil_test.go

@@ -18,24 +18,19 @@ package admission
 
 import (
 	"fmt"
-	"strconv"
 	"testing"
 
 	"github.com/prometheus/client_golang/prometheus"
 	ptype "github.com/prometheus/client_model/go"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
+// FakeHandler provide a mock implement both MutationInterface and ValidationInterface that tracks which
+// methods have been called and always returns an error if admit is false.
 type FakeHandler struct {
 	*Handler
-	name                     string
-	admit, admitCalled       bool
-	validate, validateCalled bool
-}
-
-func (h *FakeHandler) GetName() string {
-	return h.name
+	admit          bool
+	admitCalled    bool
+	validateCalled bool
 }
 
 func (h *FakeHandler) Admit(a Attributes) (err error) {
@@ -47,105 +42,125 @@ func (h *FakeHandler) Admit(a Attributes) (err error) {
 }
 
 func (h *FakeHandler) Validate(a Attributes) (err error) {
-	h.admitCalled = true
+	h.validateCalled = true
 	if h.admit {
 		return nil
 	}
 	return fmt.Errorf("Don't admit")
 }
 
-// makeHandler creates a mock handler for testing purposes.
-func makeHandler(name string, admit bool, ops ...Operation) *FakeHandler {
+func makeHandler(admit bool, ops ...Operation) *FakeHandler {
 	return &FakeHandler{
-		name:    name,
 		admit:   admit,
 		Handler: NewHandler(ops...),
 	}
 }
 
-type metricLabels struct {
-	operation   string
-	group       string
-	version     string
-	resource    string
-	subresource string
-	name        string
-	tpe         string
-	isSystemNs  bool
+func makeNamedHandler(name string, admit bool, ops ...Operation) NamedHandler {
+	return &pluginHandler{
+		i: &FakeHandler{
+			admit:   admit,
+			Handler: NewHandler(ops...),
+		},
+		name: name,
+	}
+}
+
+// FakeValidatingHandler provide a mock of ValidationInterface that tracks which
+// methods have been called and always returns an error if validate is false.
+type FakeValidatingHandler struct {
+	*Handler
+	validate, validateCalled bool
+}
+
+func (h *FakeValidatingHandler) Validate(a Attributes) (err error) {
+	h.validateCalled = true
+	if h.validate {
+		return nil
+	}
+	return fmt.Errorf("Don't validate")
 }
 
-// matches checks if the reciever matches the pattern. Empty strings in the pattern are treated as wildcards.
-func (l metricLabels) matches(pattern metricLabels) bool {
-	return matches(l.operation, pattern.operation) &&
-		matches(l.group, pattern.group) &&
-		matches(l.version, pattern.version) &&
-		matches(l.resource, pattern.resource) &&
-		matches(l.subresource, pattern.subresource) &&
-		matches(l.tpe, pattern.tpe) &&
-		l.isSystemNs == pattern.isSystemNs
+func makeValidatingHandler(validate bool, ops ...Operation) *FakeValidatingHandler {
+	return &FakeValidatingHandler{
+		validate: validate,
+		Handler:  NewHandler(ops...),
+	}
 }
 
-// matches checks if a string matches a "pattern" string, where an empty pattern string is treated as a wildcard.
-func matches(s string, pattern string) bool {
-	return pattern == "" || s == pattern
+func makeValidatingNamedHandler(name string, validate bool, ops ...Operation) NamedHandler {
+	return &pluginHandler{
+		i: &FakeValidatingHandler{
+			validate: validate,
+			Handler:  NewHandler(ops...),
+		},
+		name: name,
+	}
 }
 
-// readLabels marshalls the labels from a prometheus metric type to a simple struct, producing test errors if
-// if any unrecognized labels are encountered.
-func readLabels(t *testing.T, metric *ptype.Metric) metricLabels {
-	l := metricLabels{}
+func labelsMatch(metric *ptype.Metric, labelFilter map[string]string) bool {
 	for _, lp := range metric.GetLabel() {
-		val := lp.GetValue()
-		switch lp.GetName() {
-		case "operation":
-			l.operation = val
-		case "group":
-			l.group = val
-		case "version":
-			l.version = val
-		case "resource":
-			l.resource = val
-		case "subresource":
-			l.subresource = val
-		case "name":
-			l.name = val
-		case "type":
-			l.tpe = val
-		case "is_system_ns":
-			ns, err := strconv.ParseBool(lp.GetValue())
-			if err != nil {
-				t.Errorf("Expected boole for is_system_ns label value, got %s", lp.GetValue())
-			} else {
-				l.isSystemNs = ns
+		if value, ok := labelFilter[lp.GetName()]; ok && lp.GetValue() != value {
+			return false
+		}
+	}
+	return true
+}
+
+// expectFindMetric find a metric with the given name nad labels or reports a fatal test error.
+func expectFindMetric(t *testing.T, name string, expectedLabels map[string]string) *ptype.Metric {
+	metrics, err := prometheus.DefaultGatherer.Gather()
+	if err != nil {
+		t.Fatalf("Failed to gather metrics: %s", err)
+	}
+
+	for _, mf := range metrics {
+		if mf.GetName() == name {
+			for _, metric := range mf.GetMetric() {
+				if labelsMatch(metric, expectedLabels) {
+					gotLabelCount := len(metric.GetLabel())
+					wantLabelCount := len(expectedLabels)
+					if wantLabelCount != gotLabelCount {
+						t.Errorf("Got metric with %d labels, but wanted %d labels. Wanted %#+v for %s",
+							gotLabelCount, wantLabelCount, expectedLabels, metric.String())
+					}
+					return metric
+				}
 			}
-		default:
-			t.Errorf("Unexpected metric label %s", lp.GetName())
 		}
 	}
-	return l
+	t.Fatalf("No metric found with name %s and labels %#+v", name, expectedLabels)
+	return nil
 }
 
-// expectCounterMetric ensures that exactly one counter metric with the given name and patternLabels exists and has
-// the provided count.
-func expectCountMetric(t *testing.T, name string, patternLabels metricLabels, wantCount int64) {
+// expectHistogramCountTotal ensures that the sum of counts of metrics matching the labelFilter is as
+// expected.
+func expectHistogramCountTotal(t *testing.T, name string, labelFilter map[string]string, wantCount int) {
 	metrics, err := prometheus.DefaultGatherer.Gather()
-	require.NoError(t, err)
+	if err != nil {
+		t.Fatalf("Failed to gather metrics: %s", err)
+	}
 
-	count := 0
+	counterSum := 0
 	for _, mf := range metrics {
 		if mf.GetName() != name {
 			continue // Ignore other metrics.
 		}
 		for _, metric := range mf.GetMetric() {
-			gotLabels := readLabels(t, metric)
-			if !gotLabels.matches(patternLabels) {
+			if !labelsMatch(metric, labelFilter) {
 				continue
 			}
-			count += 1
-			assert.EqualValues(t, wantCount, metric.GetCounter().GetValue())
+			counterSum += int(metric.GetHistogram().GetSampleCount())
 		}
 	}
-	if count != 1 {
-		t.Errorf("Want 1 metric with name %s, got %d", name, count)
+	if wantCount != counterSum {
+		t.Errorf("Wanted count %d, got %d for metric %s with labels %#+v", wantCount, counterSum, name, labelFilter)
+		for _, mf := range metrics {
+			if mf.GetName() == name {
+				for _, metric := range mf.GetMetric() {
+					t.Logf("\tnear match: %s", metric.String())
+				}
+			}
+		}
 	}
 }