build source

vendor/k8s.io/client-go/discovery/aggregated_discovery.go

@@ -0,0 +1,278 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package discovery
+
+import (
+	"fmt"
+
+	apidiscovery "k8s.io/api/apidiscovery/v2"
+	apidiscoveryv2beta1 "k8s.io/api/apidiscovery/v2beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// StaleGroupVersionError encasulates failed GroupVersion marked "stale"
+// in the returned AggregatedDiscovery format.
+type StaleGroupVersionError struct {
+	gv schema.GroupVersion
+}
+
+func (s StaleGroupVersionError) Error() string {
+	return fmt.Sprintf("stale GroupVersion discovery: %v", s.gv)
+}
+
+// SplitGroupsAndResources transforms "aggregated" discovery top-level structure into
+// the previous "unaggregated" discovery groups and resources.
+func SplitGroupsAndResources(aggregatedGroups apidiscovery.APIGroupDiscoveryList) (
+	*metav1.APIGroupList,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error) {
+	// Aggregated group list will contain the entirety of discovery, including
+	// groups, versions, and resources. GroupVersions marked "stale" are failed.
+	groups := []*metav1.APIGroup{}
+	failedGVs := map[schema.GroupVersion]error{}
+	resourcesByGV := map[schema.GroupVersion]*metav1.APIResourceList{}
+	for _, aggGroup := range aggregatedGroups.Items {
+		group, resources, failed := convertAPIGroup(aggGroup)
+		groups = append(groups, group)
+		for gv, resourceList := range resources {
+			resourcesByGV[gv] = resourceList
+		}
+		for gv, err := range failed {
+			failedGVs[gv] = err
+		}
+	}
+	// Transform slice of groups to group list before returning.
+	groupList := &metav1.APIGroupList{}
+	groupList.Groups = make([]metav1.APIGroup, 0, len(groups))
+	for _, group := range groups {
+		groupList.Groups = append(groupList.Groups, *group)
+	}
+	return groupList, resourcesByGV, failedGVs
+}
+
+// convertAPIGroup tranforms an "aggregated" APIGroupDiscovery to an "legacy" APIGroup,
+// also returning the map of APIResourceList for resources within GroupVersions.
+func convertAPIGroup(g apidiscovery.APIGroupDiscovery) (
+	*metav1.APIGroup,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error) {
+	// Iterate through versions to convert to group and resources.
+	group := &metav1.APIGroup{}
+	gvResources := map[schema.GroupVersion]*metav1.APIResourceList{}
+	failedGVs := map[schema.GroupVersion]error{}
+	group.Name = g.ObjectMeta.Name
+	for _, v := range g.Versions {
+		gv := schema.GroupVersion{Group: g.Name, Version: v.Version}
+		if v.Freshness == apidiscovery.DiscoveryFreshnessStale {
+			failedGVs[gv] = StaleGroupVersionError{gv: gv}
+			continue
+		}
+		version := metav1.GroupVersionForDiscovery{}
+		version.GroupVersion = gv.String()
+		version.Version = v.Version
+		group.Versions = append(group.Versions, version)
+		// PreferredVersion is first non-stale Version
+		if group.PreferredVersion == (metav1.GroupVersionForDiscovery{}) {
+			group.PreferredVersion = version
+		}
+		resourceList := &metav1.APIResourceList{}
+		resourceList.GroupVersion = gv.String()
+		for _, r := range v.Resources {
+			resource, err := convertAPIResource(r)
+			if err == nil {
+				resourceList.APIResources = append(resourceList.APIResources, resource)
+			}
+			// Subresources field in new format get transformed into full APIResources.
+			// It is possible a partial result with an error was returned to be used
+			// as the parent resource for the subresource.
+			for _, subresource := range r.Subresources {
+				sr, err := convertAPISubresource(resource, subresource)
+				if err == nil {
+					resourceList.APIResources = append(resourceList.APIResources, sr)
+				}
+			}
+		}
+		gvResources[gv] = resourceList
+	}
+	return group, gvResources, failedGVs
+}
+
+var emptyKind = metav1.GroupVersionKind{}
+
+// convertAPIResource tranforms a APIResourceDiscovery to an APIResource. We are
+// resilient to missing GVK, since this resource might be the parent resource
+// for a subresource. If the parent is missing a GVK, it is not returned in
+// discovery, and the subresource MUST have the GVK.
+func convertAPIResource(in apidiscovery.APIResourceDiscovery) (metav1.APIResource, error) {
+	result := metav1.APIResource{
+		Name:         in.Resource,
+		SingularName: in.SingularResource,
+		Namespaced:   in.Scope == apidiscovery.ScopeNamespace,
+		Verbs:        in.Verbs,
+		ShortNames:   in.ShortNames,
+		Categories:   in.Categories,
+	}
+	var err error
+	if in.ResponseKind != nil && (*in.ResponseKind) != emptyKind {
+		result.Group = in.ResponseKind.Group
+		result.Version = in.ResponseKind.Version
+		result.Kind = in.ResponseKind.Kind
+	} else {
+		err = fmt.Errorf("discovery resource %s missing GVK", in.Resource)
+	}
+	// Can return partial result with error, which can be the parent for a
+	// subresource. Do not add this result to the returned discovery resources.
+	return result, err
+}
+
+// convertAPISubresource tranforms a APISubresourceDiscovery to an APIResource.
+func convertAPISubresource(parent metav1.APIResource, in apidiscovery.APISubresourceDiscovery) (metav1.APIResource, error) {
+	result := metav1.APIResource{}
+	if in.ResponseKind == nil || (*in.ResponseKind) == emptyKind {
+		return result, fmt.Errorf("subresource %s/%s missing GVK", parent.Name, in.Subresource)
+	}
+	result.Name = fmt.Sprintf("%s/%s", parent.Name, in.Subresource)
+	result.SingularName = parent.SingularName
+	result.Namespaced = parent.Namespaced
+	result.Group = in.ResponseKind.Group
+	result.Version = in.ResponseKind.Version
+	result.Kind = in.ResponseKind.Kind
+	result.Verbs = in.Verbs
+	return result, nil
+}
+
+// Please note the functions below will be removed in v1.35. They facilitate conversion
+// between the deprecated type apidiscoveryv2beta1.APIGroupDiscoveryList.
+
+// SplitGroupsAndResourcesV2Beta1 transforms "aggregated" discovery top-level structure into
+// the previous "unaggregated" discovery groups and resources.
+// Deprecated: Please use SplitGroupsAndResources
+func SplitGroupsAndResourcesV2Beta1(aggregatedGroups apidiscoveryv2beta1.APIGroupDiscoveryList) (
+	*metav1.APIGroupList,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error) {
+	// Aggregated group list will contain the entirety of discovery, including
+	// groups, versions, and resources. GroupVersions marked "stale" are failed.
+	groups := []*metav1.APIGroup{}
+	failedGVs := map[schema.GroupVersion]error{}
+	resourcesByGV := map[schema.GroupVersion]*metav1.APIResourceList{}
+	for _, aggGroup := range aggregatedGroups.Items {
+		group, resources, failed := convertAPIGroupv2beta1(aggGroup)
+		groups = append(groups, group)
+		for gv, resourceList := range resources {
+			resourcesByGV[gv] = resourceList
+		}
+		for gv, err := range failed {
+			failedGVs[gv] = err
+		}
+	}
+	// Transform slice of groups to group list before returning.
+	groupList := &metav1.APIGroupList{}
+	groupList.Groups = make([]metav1.APIGroup, 0, len(groups))
+	for _, group := range groups {
+		groupList.Groups = append(groupList.Groups, *group)
+	}
+	return groupList, resourcesByGV, failedGVs
+}
+
+// convertAPIGroupv2beta1 tranforms an "aggregated" APIGroupDiscovery to an "legacy" APIGroup,
+// also returning the map of APIResourceList for resources within GroupVersions.
+func convertAPIGroupv2beta1(g apidiscoveryv2beta1.APIGroupDiscovery) (
+	*metav1.APIGroup,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error) {
+	// Iterate through versions to convert to group and resources.
+	group := &metav1.APIGroup{}
+	gvResources := map[schema.GroupVersion]*metav1.APIResourceList{}
+	failedGVs := map[schema.GroupVersion]error{}
+	group.Name = g.ObjectMeta.Name
+	for _, v := range g.Versions {
+		gv := schema.GroupVersion{Group: g.Name, Version: v.Version}
+		if v.Freshness == apidiscoveryv2beta1.DiscoveryFreshnessStale {
+			failedGVs[gv] = StaleGroupVersionError{gv: gv}
+			continue
+		}
+		version := metav1.GroupVersionForDiscovery{}
+		version.GroupVersion = gv.String()
+		version.Version = v.Version
+		group.Versions = append(group.Versions, version)
+		// PreferredVersion is first non-stale Version
+		if group.PreferredVersion == (metav1.GroupVersionForDiscovery{}) {
+			group.PreferredVersion = version
+		}
+		resourceList := &metav1.APIResourceList{}
+		resourceList.GroupVersion = gv.String()
+		for _, r := range v.Resources {
+			resource, err := convertAPIResourcev2beta1(r)
+			if err == nil {
+				resourceList.APIResources = append(resourceList.APIResources, resource)
+			}
+			// Subresources field in new format get transformed into full APIResources.
+			// It is possible a partial result with an error was returned to be used
+			// as the parent resource for the subresource.
+			for _, subresource := range r.Subresources {
+				sr, err := convertAPISubresourcev2beta1(resource, subresource)
+				if err == nil {
+					resourceList.APIResources = append(resourceList.APIResources, sr)
+				}
+			}
+		}
+		gvResources[gv] = resourceList
+	}
+	return group, gvResources, failedGVs
+}
+
+// convertAPIResource tranforms a APIResourceDiscovery to an APIResource. We are
+// resilient to missing GVK, since this resource might be the parent resource
+// for a subresource. If the parent is missing a GVK, it is not returned in
+// discovery, and the subresource MUST have the GVK.
+func convertAPIResourcev2beta1(in apidiscoveryv2beta1.APIResourceDiscovery) (metav1.APIResource, error) {
+	result := metav1.APIResource{
+		Name:         in.Resource,
+		SingularName: in.SingularResource,
+		Namespaced:   in.Scope == apidiscoveryv2beta1.ScopeNamespace,
+		Verbs:        in.Verbs,
+		ShortNames:   in.ShortNames,
+		Categories:   in.Categories,
+	}
+	// Can return partial result with error, which can be the parent for a
+	// subresource. Do not add this result to the returned discovery resources.
+	if in.ResponseKind == nil || (*in.ResponseKind) == emptyKind {
+		return result, fmt.Errorf("discovery resource %s missing GVK", in.Resource)
+	}
+	result.Group = in.ResponseKind.Group
+	result.Version = in.ResponseKind.Version
+	result.Kind = in.ResponseKind.Kind
+	return result, nil
+}
+
+// convertAPISubresource tranforms a APISubresourceDiscovery to an APIResource.
+func convertAPISubresourcev2beta1(parent metav1.APIResource, in apidiscoveryv2beta1.APISubresourceDiscovery) (metav1.APIResource, error) {
+	result := metav1.APIResource{}
+	if in.ResponseKind == nil || (*in.ResponseKind) == emptyKind {
+		return result, fmt.Errorf("subresource %s/%s missing GVK", parent.Name, in.Subresource)
+	}
+	result.Name = fmt.Sprintf("%s/%s", parent.Name, in.Subresource)
+	result.SingularName = parent.SingularName
+	result.Namespaced = parent.Namespaced
+	result.Group = in.ResponseKind.Group
+	result.Version = in.ResponseKind.Version
+	result.Kind = in.ResponseKind.Kind
+	result.Verbs = in.Verbs
+	return result, nil
+}

vendor/k8s.io/client-go/discovery/discovery_client.go

@@ -0,0 +1,795 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package discovery
+
+import (
+	"context"
+	"encoding/json"
+	goerrors "errors"
+	"fmt"
+	"mime"
+	"net/http"
+	"net/url"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	openapi_v2 "github.com/google/gnostic-models/openapiv2"
+	"google.golang.org/protobuf/proto"
+
+	apidiscoveryv2 "k8s.io/api/apidiscovery/v2"
+	apidiscoveryv2beta1 "k8s.io/api/apidiscovery/v2beta1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/version"
+	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/client-go/openapi"
+	restclient "k8s.io/client-go/rest"
+)
+
+const (
+	// defaultRetries is the number of times a resource discovery is repeated if an api group disappears on the fly (e.g. CustomResourceDefinitions).
+	defaultRetries = 2
+	// protobuf mime type
+	openAPIV2mimePb = "application/com.github.proto-openapi.spec.v2@v1.0+protobuf"
+
+	// defaultTimeout is the maximum amount of time per request when no timeout has been set on a RESTClient.
+	// Defaults to 32s in order to have a distinguishable length of time, relative to other timeouts that exist.
+	defaultTimeout = 32 * time.Second
+
+	// defaultBurst is the default burst to be used with the discovery client's token bucket rate limiter
+	defaultBurst = 300
+
+	AcceptV1 = runtime.ContentTypeJSON
+	// Aggregated discovery content-type (v2beta1). NOTE: content-type parameters
+	// MUST be ordered (g, v, as) for server in "Accept" header (BUT we are resilient
+	// to ordering when comparing returned values in "Content-Type" header).
+	AcceptV2Beta1  = runtime.ContentTypeJSON + ";" + "g=apidiscovery.k8s.io;v=v2beta1;as=APIGroupDiscoveryList"
+	AcceptV2       = runtime.ContentTypeJSON + ";" + "g=apidiscovery.k8s.io;v=v2;as=APIGroupDiscoveryList"
+	AcceptV2NoPeer = runtime.ContentTypeJSON + ";" + "g=apidiscovery.k8s.io;v=v2;as=APIGroupDiscoveryList;profile=nopeer"
+	// Prioritize aggregated discovery by placing first in the order of discovery accept types.
+	acceptDiscoveryFormats = AcceptV2 + "," + AcceptV2Beta1 + "," + AcceptV1
+)
+
+// Aggregated discovery content-type GVK.
+var v2Beta1GVK = schema.GroupVersionKind{Group: "apidiscovery.k8s.io", Version: "v2beta1", Kind: "APIGroupDiscoveryList"}
+var v2GVK = schema.GroupVersionKind{Group: "apidiscovery.k8s.io", Version: "v2", Kind: "APIGroupDiscoveryList"}
+
+// DiscoveryInterface holds the methods that discover server-supported API groups,
+// versions and resources.
+type DiscoveryInterface interface {
+	RESTClient() restclient.Interface
+	ServerGroupsInterface
+	ServerResourcesInterface
+	ServerVersionInterface
+	OpenAPISchemaInterface
+	OpenAPIV3SchemaInterface
+	// Returns copy of current discovery client that will only
+	// receive the legacy discovery format, or pointer to current
+	// discovery client if it does not support legacy-only discovery.
+	WithLegacy() DiscoveryInterface
+}
+
+// AggregatedDiscoveryInterface extends DiscoveryInterface to include a method to possibly
+// return discovery resources along with the discovery groups, which is what the newer
+// aggregated discovery format does (APIGroupDiscoveryList).
+type AggregatedDiscoveryInterface interface {
+	DiscoveryInterface
+
+	GroupsAndMaybeResources() (*metav1.APIGroupList, map[schema.GroupVersion]*metav1.APIResourceList, map[schema.GroupVersion]error, error)
+}
+
+// CachedDiscoveryInterface is a DiscoveryInterface with cache invalidation and freshness.
+// Note that If the ServerResourcesForGroupVersion method returns a cache miss
+// error, the user needs to explicitly call Invalidate to clear the cache,
+// otherwise the same cache miss error will be returned next time.
+type CachedDiscoveryInterface interface {
+	DiscoveryInterface
+	// Fresh is supposed to tell the caller whether or not to retry if the cache
+	// fails to find something (false = retry, true = no need to retry).
+	//
+	// TODO: this needs to be revisited, this interface can't be locked properly
+	// and doesn't make a lot of sense.
+	Fresh() bool
+	// Invalidate enforces that no cached data that is older than the current time
+	// is used.
+	Invalidate()
+}
+
+// ServerGroupsInterface has methods for obtaining supported groups on the API server
+type ServerGroupsInterface interface {
+	// ServerGroups returns the supported groups, with information like supported versions and the
+	// preferred version.
+	ServerGroups() (*metav1.APIGroupList, error)
+}
+
+// ServerResourcesInterface has methods for obtaining supported resources on the API server
+type ServerResourcesInterface interface {
+	// ServerResourcesForGroupVersion returns the supported resources for a group and version.
+	ServerResourcesForGroupVersion(groupVersion string) (*metav1.APIResourceList, error)
+	// ServerGroupsAndResources returns the supported groups and resources for all groups and versions.
+	//
+	// The returned group and resource lists might be non-nil with partial results even in the
+	// case of non-nil error.
+	ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error)
+	// ServerPreferredResources returns the supported resources with the version preferred by the
+	// server.
+	//
+	// The returned group and resource lists might be non-nil with partial results even in the
+	// case of non-nil error.
+	ServerPreferredResources() ([]*metav1.APIResourceList, error)
+	// ServerPreferredNamespacedResources returns the supported namespaced resources with the
+	// version preferred by the server.
+	//
+	// The returned resource list might be non-nil with partial results even in the case of
+	// non-nil error.
+	ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error)
+}
+
+// ServerVersionInterface has a method for retrieving the server's version.
+type ServerVersionInterface interface {
+	// ServerVersion retrieves and parses the server's version (git version).
+	ServerVersion() (*version.Info, error)
+}
+
+// OpenAPISchemaInterface has a method to retrieve the open API schema.
+type OpenAPISchemaInterface interface {
+	// OpenAPISchema retrieves and parses the swagger API schema the server supports.
+	OpenAPISchema() (*openapi_v2.Document, error)
+}
+
+type OpenAPIV3SchemaInterface interface {
+	OpenAPIV3() openapi.Client
+}
+
+// DiscoveryClient implements the functions that discover server-supported API groups,
+// versions and resources.
+type DiscoveryClient struct {
+	restClient restclient.Interface
+
+	LegacyPrefix string
+	// Forces the client to request only "unaggregated" (legacy) discovery.
+	UseLegacyDiscovery bool
+	// NoPeerDiscovery will request the "nopeer" profile of aggregated discovery.
+	// This allows a client to get just the discovery documents served by the single apiserver
+	// that it is talking to. This is useful for clients that need to understand the state
+	// of a single apiserver, for example, to validate that the apiserver is ready to serve traffic.
+	NoPeerDiscovery bool
+}
+
+var _ AggregatedDiscoveryInterface = &DiscoveryClient{}
+
+// Convert metav1.APIVersions to metav1.APIGroup. APIVersions is used by legacy v1, so
+// group would be "".
+func apiVersionsToAPIGroup(apiVersions *metav1.APIVersions) (apiGroup metav1.APIGroup) {
+	groupVersions := []metav1.GroupVersionForDiscovery{}
+	for _, version := range apiVersions.Versions {
+		groupVersion := metav1.GroupVersionForDiscovery{
+			GroupVersion: version,
+			Version:      version,
+		}
+		groupVersions = append(groupVersions, groupVersion)
+	}
+	apiGroup.Versions = groupVersions
+	// There should be only one groupVersion returned at /api
+	apiGroup.PreferredVersion = groupVersions[0]
+	return
+}
+
+// GroupsAndMaybeResources returns the discovery groups, and (if new aggregated
+// discovery format) the resources keyed by group/version. Merges discovery groups
+// and resources from /api and /apis (either aggregated or not). Legacy groups
+// must be ordered first. The server will either return both endpoints (/api, /apis)
+// as aggregated discovery format or legacy format. For safety, resources will only
+// be returned if both endpoints returned resources. Returned "failedGVs" can be
+// empty, but will only be nil in the case an error is returned.
+func (d *DiscoveryClient) GroupsAndMaybeResources() (
+	*metav1.APIGroupList,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error,
+	error) {
+	// Legacy group ordered first (there is only one -- core/v1 group). Returned groups must
+	// be non-nil, but it could be empty. Returned resources, apiResources map could be nil.
+	groups, resources, failedGVs, err := d.downloadLegacy()
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	// Discovery groups and (possibly) resources downloaded from /apis.
+	apiGroups, apiResources, failedApisGVs, aerr := d.downloadAPIs()
+	if aerr != nil {
+		return nil, nil, nil, aerr
+	}
+	// Merge apis groups into the legacy groups.
+	for _, group := range apiGroups.Groups {
+		groups.Groups = append(groups.Groups, group)
+	}
+	// For safety, only return resources if both endpoints returned resources.
+	if resources != nil && apiResources != nil {
+		for gv, resourceList := range apiResources {
+			resources[gv] = resourceList
+		}
+	} else if resources != nil {
+		resources = nil
+	}
+	// Merge failed GroupVersions from /api and /apis
+	for gv, err := range failedApisGVs {
+		failedGVs[gv] = err
+	}
+	return groups, resources, failedGVs, err
+}
+
+// downloadLegacy returns the discovery groups and possibly resources
+// for the legacy v1 GVR at /api, or an error if one occurred. It is
+// possible for the resource map to be nil if the server returned
+// the unaggregated discovery. Returned "failedGVs" can be empty, but
+// will only be nil in the case of a returned error.
+func (d *DiscoveryClient) downloadLegacy() (
+	*metav1.APIGroupList,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error,
+	error) {
+	accept := selectDiscoveryAcceptHeader(d.UseLegacyDiscovery, d.NoPeerDiscovery)
+	var responseContentType string
+	body, err := d.restClient.Get().
+		AbsPath("/api").
+		SetHeader("Accept", accept).
+		Do(context.TODO()).
+		ContentType(&responseContentType).
+		Raw()
+	apiGroupList := &metav1.APIGroupList{}
+	failedGVs := map[schema.GroupVersion]error{}
+	if err != nil {
+		// Tolerate 404, since aggregated api servers can return it.
+		if errors.IsNotFound(err) {
+			// Return empty structures and no error.
+			emptyGVMap := map[schema.GroupVersion]*metav1.APIResourceList{}
+			return apiGroupList, emptyGVMap, failedGVs, nil
+		} else {
+			return nil, nil, nil, err
+		}
+	}
+
+	var resourcesByGV map[schema.GroupVersion]*metav1.APIResourceList
+	// Based on the content-type server responded with: aggregated or unaggregated.
+	if isGVK, _ := ContentTypeIsGVK(responseContentType, v2GVK); isGVK {
+		var aggregatedDiscovery apidiscoveryv2.APIGroupDiscoveryList
+		err = json.Unmarshal(body, &aggregatedDiscovery)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		apiGroupList, resourcesByGV, failedGVs = SplitGroupsAndResources(aggregatedDiscovery)
+	} else if isGVK, _ := ContentTypeIsGVK(responseContentType, v2Beta1GVK); isGVK {
+		var aggregatedDiscovery apidiscoveryv2beta1.APIGroupDiscoveryList
+		err = json.Unmarshal(body, &aggregatedDiscovery)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		apiGroupList, resourcesByGV, failedGVs = SplitGroupsAndResourcesV2Beta1(aggregatedDiscovery)
+	} else {
+		// Default is unaggregated discovery v1.
+		var v metav1.APIVersions
+		err = json.Unmarshal(body, &v)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		apiGroup := metav1.APIGroup{}
+		if len(v.Versions) != 0 {
+			apiGroup = apiVersionsToAPIGroup(&v)
+		}
+		apiGroupList.Groups = []metav1.APIGroup{apiGroup}
+	}
+
+	return apiGroupList, resourcesByGV, failedGVs, nil
+}
+
+// downloadAPIs returns the discovery groups and (if aggregated format) the
+// discovery resources. The returned groups will always exist, but the
+// resources map may be nil. Returned "failedGVs" can be empty, but will
+// only be nil in the case of a returned error.
+func (d *DiscoveryClient) downloadAPIs() (
+	*metav1.APIGroupList,
+	map[schema.GroupVersion]*metav1.APIResourceList,
+	map[schema.GroupVersion]error,
+	error) {
+	accept := selectDiscoveryAcceptHeader(d.UseLegacyDiscovery, d.NoPeerDiscovery)
+	var responseContentType string
+	body, err := d.restClient.Get().
+		AbsPath("/apis").
+		SetHeader("Accept", accept).
+		Do(context.TODO()).
+		ContentType(&responseContentType).
+		Raw()
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	apiGroupList := &metav1.APIGroupList{}
+	failedGVs := map[schema.GroupVersion]error{}
+	var resourcesByGV map[schema.GroupVersion]*metav1.APIResourceList
+	// Based on the content-type server responded with: aggregated or unaggregated.
+	if isGVK, _ := ContentTypeIsGVK(responseContentType, v2GVK); isGVK {
+		var aggregatedDiscovery apidiscoveryv2.APIGroupDiscoveryList
+		err = json.Unmarshal(body, &aggregatedDiscovery)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		apiGroupList, resourcesByGV, failedGVs = SplitGroupsAndResources(aggregatedDiscovery)
+	} else if isGVK, _ := ContentTypeIsGVK(responseContentType, v2Beta1GVK); isGVK {
+		var aggregatedDiscovery apidiscoveryv2beta1.APIGroupDiscoveryList
+		err = json.Unmarshal(body, &aggregatedDiscovery)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		apiGroupList, resourcesByGV, failedGVs = SplitGroupsAndResourcesV2Beta1(aggregatedDiscovery)
+	} else {
+		// Default is unaggregated discovery v1.
+		err = json.Unmarshal(body, apiGroupList)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+	}
+
+	return apiGroupList, resourcesByGV, failedGVs, nil
+}
+
+func selectDiscoveryAcceptHeader(useLegacy, nopeer bool) string {
+	if useLegacy {
+		return AcceptV1
+	}
+	if nopeer {
+		return AcceptV2NoPeer + "," + acceptDiscoveryFormats
+	}
+	return acceptDiscoveryFormats
+}
+
+// ContentTypeIsGVK checks of the content-type string is both
+// "application/json" and matches the provided GVK. An error
+// is returned if the content type string is malformed.
+// NOTE: This function is resilient to the ordering of the
+// content-type parameters, as well as parameters added by
+// intermediaries such as proxies or gateways. Examples:
+//
+//	("application/json; g=apidiscovery.k8s.io;v=v2beta1;as=APIGroupDiscoveryList", {apidiscovery.k8s.io, v2beta1, APIGroupDiscoveryList}) = (true, nil)
+//	("application/json; as=APIGroupDiscoveryList;v=v2beta1;g=apidiscovery.k8s.io", {apidiscovery.k8s.io, v2beta1, APIGroupDiscoveryList}) = (true, nil)
+//	("application/json; as=APIGroupDiscoveryList;v=v2beta1;g=apidiscovery.k8s.io;charset=utf-8", {apidiscovery.k8s.io, v2beta1, APIGroupDiscoveryList}) = (true, nil)
+//	("application/json", any GVK) = (false, nil)
+//	("application/json; charset=UTF-8", any GVK) = (false, nil)
+//	("malformed content type string", any GVK) = (false, error)
+func ContentTypeIsGVK(contentType string, gvk schema.GroupVersionKind) (bool, error) {
+	base, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return false, err
+	}
+	gvkMatch := runtime.ContentTypeJSON == base &&
+		params["g"] == gvk.Group &&
+		params["v"] == gvk.Version &&
+		params["as"] == gvk.Kind
+	return gvkMatch, nil
+}
+
+// ServerGroups returns the supported groups, with information like supported versions and the
+// preferred version.
+func (d *DiscoveryClient) ServerGroups() (*metav1.APIGroupList, error) {
+	groups, _, _, err := d.GroupsAndMaybeResources()
+	if err != nil {
+		return nil, err
+	}
+	return groups, nil
+}
+
+// ServerResourcesForGroupVersion returns the supported resources for a group and version.
+func (d *DiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (resources *metav1.APIResourceList, err error) {
+	url := url.URL{}
+	if len(groupVersion) == 0 {
+		return nil, fmt.Errorf("groupVersion shouldn't be empty")
+	}
+	if len(d.LegacyPrefix) > 0 && groupVersion == "v1" {
+		url.Path = d.LegacyPrefix + "/" + groupVersion
+	} else {
+		url.Path = "/apis/" + groupVersion
+	}
+	resources = &metav1.APIResourceList{
+		GroupVersion: groupVersion,
+	}
+	err = d.restClient.Get().AbsPath(url.String()).Do(context.TODO()).Into(resources)
+	if err != nil {
+		// Tolerate core/v1 not found response by returning empty resource list;
+		// this probably should not happen. But we should verify all callers are
+		// not depending on this toleration before removal.
+		if groupVersion == "v1" && errors.IsNotFound(err) {
+			return resources, nil
+		}
+		return nil, err
+	}
+	return resources, nil
+}
+
+// ServerGroupsAndResources returns the supported resources for all groups and versions.
+func (d *DiscoveryClient) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	return withRetries(defaultRetries, func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+		return ServerGroupsAndResources(d)
+	})
+}
+
+// ErrGroupDiscoveryFailed is returned if one or more API groups fail to load.
+type ErrGroupDiscoveryFailed struct {
+	// Groups is a list of the groups that failed to load and the error cause
+	Groups map[schema.GroupVersion]error
+}
+
+// Error implements the error interface
+func (e *ErrGroupDiscoveryFailed) Error() string {
+	var groups []string
+	for k, v := range e.Groups {
+		groups = append(groups, fmt.Sprintf("%s: %v", k, v))
+	}
+	sort.Strings(groups)
+	return fmt.Sprintf("unable to retrieve the complete list of server APIs: %s", strings.Join(groups, ", "))
+}
+
+// Is makes it possible for the callers to use `errors.Is(` helper on errors wrapped with ErrGroupDiscoveryFailed error.
+func (e *ErrGroupDiscoveryFailed) Is(target error) bool {
+	_, ok := target.(*ErrGroupDiscoveryFailed)
+	return ok
+}
+
+// IsGroupDiscoveryFailedError returns true if the provided error indicates the server was unable to discover
+// a complete list of APIs for the client to use.
+func IsGroupDiscoveryFailedError(err error) bool {
+	_, ok := err.(*ErrGroupDiscoveryFailed)
+	return err != nil && ok
+}
+
+// GroupDiscoveryFailedErrorGroups returns true if the error is an ErrGroupDiscoveryFailed error,
+// along with the map of group versions that failed discovery.
+func GroupDiscoveryFailedErrorGroups(err error) (map[schema.GroupVersion]error, bool) {
+	var groupDiscoveryError *ErrGroupDiscoveryFailed
+	if err != nil && goerrors.As(err, &groupDiscoveryError) {
+		return groupDiscoveryError.Groups, true
+	}
+	return nil, false
+}
+
+func ServerGroupsAndResources(d DiscoveryInterface) ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	var sgs *metav1.APIGroupList
+	var resources []*metav1.APIResourceList
+	var failedGVs map[schema.GroupVersion]error
+	var err error
+
+	// If the passed discovery object implements the wider AggregatedDiscoveryInterface,
+	// then attempt to retrieve aggregated discovery with both groups and the resources.
+	if ad, ok := d.(AggregatedDiscoveryInterface); ok {
+		var resourcesByGV map[schema.GroupVersion]*metav1.APIResourceList
+		sgs, resourcesByGV, failedGVs, err = ad.GroupsAndMaybeResources()
+		for _, resourceList := range resourcesByGV {
+			resources = append(resources, resourceList)
+		}
+	} else {
+		sgs, err = d.ServerGroups()
+	}
+
+	if sgs == nil {
+		return nil, nil, err
+	}
+	resultGroups := []*metav1.APIGroup{}
+	for i := range sgs.Groups {
+		resultGroups = append(resultGroups, &sgs.Groups[i])
+	}
+	// resources is non-nil if aggregated discovery succeeded.
+	if resources != nil {
+		// Any stale Group/Versions returned by aggregated discovery
+		// must be surfaced to the caller as failed Group/Versions.
+		var ferr error
+		if len(failedGVs) > 0 {
+			ferr = &ErrGroupDiscoveryFailed{Groups: failedGVs}
+		}
+		return resultGroups, resources, ferr
+	}
+
+	groupVersionResources, failedGroups := fetchGroupVersionResources(d, sgs)
+
+	// order results by group/version discovery order
+	result := []*metav1.APIResourceList{}
+	for _, apiGroup := range sgs.Groups {
+		for _, version := range apiGroup.Versions {
+			gv := schema.GroupVersion{Group: apiGroup.Name, Version: version.Version}
+			if resources, ok := groupVersionResources[gv]; ok {
+				result = append(result, resources)
+			}
+		}
+	}
+
+	if len(failedGroups) == 0 {
+		return resultGroups, result, nil
+	}
+
+	return resultGroups, result, &ErrGroupDiscoveryFailed{Groups: failedGroups}
+}
+
+// ServerPreferredResources uses the provided discovery interface to look up preferred resources
+func ServerPreferredResources(d DiscoveryInterface) ([]*metav1.APIResourceList, error) {
+	var serverGroupList *metav1.APIGroupList
+	var failedGroups map[schema.GroupVersion]error
+	var groupVersionResources map[schema.GroupVersion]*metav1.APIResourceList
+	var err error
+
+	// If the passed discovery object implements the wider AggregatedDiscoveryInterface,
+	// then it is attempt to retrieve both the groups and the resources. "failedGroups"
+	// are Group/Versions returned as stale in AggregatedDiscovery format.
+	ad, ok := d.(AggregatedDiscoveryInterface)
+	if ok {
+		serverGroupList, groupVersionResources, failedGroups, err = ad.GroupsAndMaybeResources()
+	} else {
+		serverGroupList, err = d.ServerGroups()
+	}
+	if err != nil {
+		return nil, err
+	}
+	// Non-aggregated discovery must fetch resources from Groups.
+	if groupVersionResources == nil {
+		groupVersionResources, failedGroups = fetchGroupVersionResources(d, serverGroupList)
+	}
+
+	result := []*metav1.APIResourceList{}
+	grVersions := map[schema.GroupResource]string{}                         // selected version of a GroupResource
+	grAPIResources := map[schema.GroupResource]*metav1.APIResource{}        // selected APIResource for a GroupResource
+	gvAPIResourceLists := map[schema.GroupVersion]*metav1.APIResourceList{} // blueprint for a APIResourceList for later grouping
+
+	for _, apiGroup := range serverGroupList.Groups {
+		for _, version := range apiGroup.Versions {
+			groupVersion := schema.GroupVersion{Group: apiGroup.Name, Version: version.Version}
+
+			apiResourceList, ok := groupVersionResources[groupVersion]
+			if !ok {
+				continue
+			}
+
+			// create empty list which is filled later in another loop
+			emptyAPIResourceList := metav1.APIResourceList{
+				GroupVersion: version.GroupVersion,
+			}
+			gvAPIResourceLists[groupVersion] = &emptyAPIResourceList
+			result = append(result, &emptyAPIResourceList)
+
+			for i := range apiResourceList.APIResources {
+				apiResource := &apiResourceList.APIResources[i]
+				if strings.Contains(apiResource.Name, "/") {
+					continue
+				}
+				gv := schema.GroupResource{Group: apiGroup.Name, Resource: apiResource.Name}
+				if _, ok := grAPIResources[gv]; ok && version.Version != apiGroup.PreferredVersion.Version {
+					// only override with preferred version
+					continue
+				}
+				grVersions[gv] = version.Version
+				grAPIResources[gv] = apiResource
+			}
+		}
+	}
+
+	// group selected APIResources according to GroupVersion into APIResourceLists
+	for groupResource, apiResource := range grAPIResources {
+		version := grVersions[groupResource]
+		groupVersion := schema.GroupVersion{Group: groupResource.Group, Version: version}
+		apiResourceList := gvAPIResourceLists[groupVersion]
+		apiResourceList.APIResources = append(apiResourceList.APIResources, *apiResource)
+	}
+
+	if len(failedGroups) == 0 {
+		return result, nil
+	}
+
+	return result, &ErrGroupDiscoveryFailed{Groups: failedGroups}
+}
+
+// fetchServerResourcesForGroupVersions uses the discovery client to fetch the resources for the specified groups in parallel.
+func fetchGroupVersionResources(d DiscoveryInterface, apiGroups *metav1.APIGroupList) (map[schema.GroupVersion]*metav1.APIResourceList, map[schema.GroupVersion]error) {
+	groupVersionResources := make(map[schema.GroupVersion]*metav1.APIResourceList)
+	failedGroups := make(map[schema.GroupVersion]error)
+
+	wg := &sync.WaitGroup{}
+	resultLock := &sync.Mutex{}
+	for _, apiGroup := range apiGroups.Groups {
+		for _, version := range apiGroup.Versions {
+			groupVersion := schema.GroupVersion{Group: apiGroup.Name, Version: version.Version}
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				defer utilruntime.HandleCrash()
+
+				apiResourceList, err := d.ServerResourcesForGroupVersion(groupVersion.String())
+
+				// lock to record results
+				resultLock.Lock()
+				defer resultLock.Unlock()
+
+				if err != nil {
+					// TODO: maybe restrict this to NotFound errors
+					failedGroups[groupVersion] = err
+				}
+				if apiResourceList != nil {
+					// even in case of error, some fallback might have been returned
+					groupVersionResources[groupVersion] = apiResourceList
+				}
+			}()
+		}
+	}
+	wg.Wait()
+
+	return groupVersionResources, failedGroups
+}
+
+// ServerPreferredResources returns the supported resources with the version preferred by the
+// server.
+func (d *DiscoveryClient) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
+	_, rs, err := withRetries(defaultRetries, func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+		rs, err := ServerPreferredResources(d)
+		return nil, rs, err
+	})
+	return rs, err
+}
+
+// ServerPreferredNamespacedResources returns the supported namespaced resources with the
+// version preferred by the server.
+func (d *DiscoveryClient) ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error) {
+	return ServerPreferredNamespacedResources(d)
+}
+
+// ServerPreferredNamespacedResources uses the provided discovery interface to look up preferred namespaced resources
+func ServerPreferredNamespacedResources(d DiscoveryInterface) ([]*metav1.APIResourceList, error) {
+	all, err := ServerPreferredResources(d)
+	return FilteredBy(ResourcePredicateFunc(func(groupVersion string, r *metav1.APIResource) bool {
+		return r.Namespaced
+	}), all), err
+}
+
+// ServerVersion retrieves and parses the server's version (git version).
+func (d *DiscoveryClient) ServerVersion() (*version.Info, error) {
+	body, err := d.restClient.Get().AbsPath("/version").Do(context.TODO()).Raw()
+	if err != nil {
+		return nil, err
+	}
+	var info version.Info
+	err = json.Unmarshal(body, &info)
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse the server version: %v", err)
+	}
+	return &info, nil
+}
+
+// OpenAPISchema fetches the open api v2 schema using a rest client and parses the proto.
+func (d *DiscoveryClient) OpenAPISchema() (*openapi_v2.Document, error) {
+	data, err := d.restClient.Get().AbsPath("/openapi/v2").SetHeader("Accept", openAPIV2mimePb).Do(context.TODO()).Raw()
+	if err != nil {
+		return nil, err
+	}
+	document := &openapi_v2.Document{}
+	err = proto.Unmarshal(data, document)
+	if err != nil {
+		return nil, err
+	}
+	return document, nil
+}
+
+func (d *DiscoveryClient) OpenAPIV3() openapi.Client {
+	return openapi.NewClient(d.restClient)
+}
+
+// WithLegacy returns copy of current discovery client that will only
+// receive the legacy discovery format.
+func (d *DiscoveryClient) WithLegacy() DiscoveryInterface {
+	client := *d
+	client.UseLegacyDiscovery = true
+	return &client
+}
+
+// withRetries retries the given recovery function in case the groups supported by the server change after ServerGroup() returns.
+func withRetries(maxRetries int, f func() ([]*metav1.APIGroup, []*metav1.APIResourceList, error)) ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	var result []*metav1.APIResourceList
+	var resultGroups []*metav1.APIGroup
+	var err error
+	for i := 0; i < maxRetries; i++ {
+		resultGroups, result, err = f()
+		if err == nil {
+			return resultGroups, result, nil
+		}
+		if _, ok := err.(*ErrGroupDiscoveryFailed); !ok {
+			return nil, nil, err
+		}
+	}
+	return resultGroups, result, err
+}
+
+func setDiscoveryDefaults(config *restclient.Config) error {
+	config.APIPath = ""
+	config.GroupVersion = nil
+	if config.Timeout == 0 {
+		config.Timeout = defaultTimeout
+	}
+	// if a burst limit is not already configured
+	if config.Burst == 0 {
+		// discovery is expected to be bursty, increase the default burst
+		// to accommodate looking up resource info for many API groups.
+		// matches burst set by ConfigFlags#ToDiscoveryClient().
+		// see https://issue.k8s.io/86149
+		config.Burst = defaultBurst
+	}
+	codec := runtime.NoopEncoder{Decoder: scheme.Codecs.UniversalDecoder()}
+	config.NegotiatedSerializer = serializer.NegotiatedSerializerWrapper(runtime.SerializerInfo{Serializer: codec})
+	if len(config.UserAgent) == 0 {
+		config.UserAgent = restclient.DefaultKubernetesUserAgent()
+	}
+	return nil
+}
+
+// NewDiscoveryClientForConfig creates a new DiscoveryClient for the given config. This client
+// can be used to discover supported resources in the API server.
+// NewDiscoveryClientForConfig is equivalent to NewDiscoveryClientForConfigAndClient(c, httpClient),
+// where httpClient was generated with rest.HTTPClientFor(c).
+func NewDiscoveryClientForConfig(c *restclient.Config) (*DiscoveryClient, error) {
+	config := *c
+	if err := setDiscoveryDefaults(&config); err != nil {
+		return nil, err
+	}
+	httpClient, err := restclient.HTTPClientFor(&config)
+	if err != nil {
+		return nil, err
+	}
+	return NewDiscoveryClientForConfigAndClient(&config, httpClient)
+}
+
+// NewDiscoveryClientForConfigAndClient creates a new DiscoveryClient for the given config. This client
+// can be used to discover supported resources in the API server.
+// Note the http client provided takes precedence over the configured transport values.
+func NewDiscoveryClientForConfigAndClient(c *restclient.Config, httpClient *http.Client) (*DiscoveryClient, error) {
+	config := *c
+	if err := setDiscoveryDefaults(&config); err != nil {
+		return nil, err
+	}
+	client, err := restclient.UnversionedRESTClientForConfigAndClient(&config, httpClient)
+	return &DiscoveryClient{restClient: client, LegacyPrefix: "/api", UseLegacyDiscovery: false}, err
+}
+
+// NewDiscoveryClientForConfigOrDie creates a new DiscoveryClient for the given config. If
+// there is an error, it panics.
+func NewDiscoveryClientForConfigOrDie(c *restclient.Config) *DiscoveryClient {
+	client, err := NewDiscoveryClientForConfig(c)
+	if err != nil {
+		panic(err)
+	}
+	return client
+
+}
+
+// NewDiscoveryClient returns a new DiscoveryClient for the given RESTClient.
+func NewDiscoveryClient(c restclient.Interface) *DiscoveryClient {
+	return &DiscoveryClient{restClient: c, LegacyPrefix: "/api", UseLegacyDiscovery: false}
+}
+
+// RESTClient returns a RESTClient that is used to communicate
+// with API server by this client implementation.
+func (d *DiscoveryClient) RESTClient() restclient.Interface {
+	if d == nil {
+		return nil
+	}
+	return d.restClient
+}

vendor/k8s.io/client-go/discovery/doc.go

@@ -0,0 +1,19 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package discovery provides ways to discover server-supported
+// API groups, versions and resources.
+package discovery

vendor/k8s.io/client-go/discovery/fake/discovery.go

@@ -0,0 +1,180 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package fake
+
+import (
+	"fmt"
+	"net/http"
+
+	openapi_v2 "github.com/google/gnostic-models/openapiv2"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/version"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/openapi"
+	kubeversion "k8s.io/client-go/pkg/version"
+	restclient "k8s.io/client-go/rest"
+	"k8s.io/client-go/testing"
+)
+
+// FakeDiscovery implements discovery.DiscoveryInterface and sometimes calls testing.Fake.Invoke with an action,
+// but doesn't respect the return value if any. There is a way to fake static values like ServerVersion by using the Faked... fields on the struct.
+type FakeDiscovery struct {
+	*testing.Fake
+	FakedServerVersion *version.Info
+}
+
+// ServerResourcesForGroupVersion returns the supported resources for a group
+// and version.
+func (c *FakeDiscovery) ServerResourcesForGroupVersion(groupVersion string) (*metav1.APIResourceList, error) {
+	action := testing.ActionImpl{
+		Verb:     "get",
+		Resource: schema.GroupVersionResource{Resource: "resource"},
+	}
+	if _, err := c.Invokes(action, nil); err != nil {
+		return nil, err
+	}
+	for _, resourceList := range c.Resources {
+		if resourceList.GroupVersion == groupVersion {
+			return resourceList, nil
+		}
+	}
+	return nil, &errors.StatusError{
+		ErrStatus: metav1.Status{
+			Status:  metav1.StatusFailure,
+			Code:    http.StatusNotFound,
+			Reason:  metav1.StatusReasonNotFound,
+			Message: fmt.Sprintf("the server could not find the requested resource, GroupVersion %q not found", groupVersion),
+		}}
+}
+
+// ServerGroupsAndResources returns the supported groups and resources for all groups and versions.
+func (c *FakeDiscovery) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	sgs, err := c.ServerGroups()
+	if err != nil {
+		return nil, nil, err
+	}
+	resultGroups := []*metav1.APIGroup{}
+	for i := range sgs.Groups {
+		resultGroups = append(resultGroups, &sgs.Groups[i])
+	}
+
+	action := testing.ActionImpl{
+		Verb:     "get",
+		Resource: schema.GroupVersionResource{Resource: "resource"},
+	}
+	if _, err = c.Invokes(action, nil); err != nil {
+		return resultGroups, c.Resources, err
+	}
+	return resultGroups, c.Resources, nil
+}
+
+// ServerPreferredResources returns the supported resources with the version
+// preferred by the server.
+func (c *FakeDiscovery) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
+	return nil, nil
+}
+
+// ServerPreferredNamespacedResources returns the supported namespaced resources
+// with the version preferred by the server.
+func (c *FakeDiscovery) ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error) {
+	return nil, nil
+}
+
+// ServerGroups returns the supported groups, with information like supported
+// versions and the preferred version.
+func (c *FakeDiscovery) ServerGroups() (*metav1.APIGroupList, error) {
+	action := testing.ActionImpl{
+		Verb:     "get",
+		Resource: schema.GroupVersionResource{Resource: "group"},
+	}
+	if _, err := c.Invokes(action, nil); err != nil {
+		return nil, err
+	}
+
+	groups := map[string]*metav1.APIGroup{}
+
+	for _, res := range c.Resources {
+		gv, err := schema.ParseGroupVersion(res.GroupVersion)
+		if err != nil {
+			return nil, err
+		}
+		group := groups[gv.Group]
+		if group == nil {
+			group = &metav1.APIGroup{
+				Name: gv.Group,
+				PreferredVersion: metav1.GroupVersionForDiscovery{
+					GroupVersion: res.GroupVersion,
+					Version:      gv.Version,
+				},
+			}
+			groups[gv.Group] = group
+		}
+
+		group.Versions = append(group.Versions, metav1.GroupVersionForDiscovery{
+			GroupVersion: res.GroupVersion,
+			Version:      gv.Version,
+		})
+	}
+
+	list := &metav1.APIGroupList{}
+	for _, apiGroup := range groups {
+		list.Groups = append(list.Groups, *apiGroup)
+	}
+
+	return list, nil
+
+}
+
+// ServerVersion retrieves and parses the server's version.
+func (c *FakeDiscovery) ServerVersion() (*version.Info, error) {
+	action := testing.ActionImpl{}
+	action.Verb = "get"
+	action.Resource = schema.GroupVersionResource{Resource: "version"}
+	_, err := c.Invokes(action, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if c.FakedServerVersion != nil {
+		return c.FakedServerVersion, nil
+	}
+
+	versionInfo := kubeversion.Get()
+	return &versionInfo, nil
+}
+
+// OpenAPISchema retrieves and parses the swagger API schema the server supports.
+func (c *FakeDiscovery) OpenAPISchema() (*openapi_v2.Document, error) {
+	return &openapi_v2.Document{}, nil
+}
+
+func (c *FakeDiscovery) OpenAPIV3() openapi.Client {
+	panic("unimplemented")
+}
+
+// RESTClient returns a RESTClient that is used to communicate with API server
+// by this client implementation.
+func (c *FakeDiscovery) RESTClient() restclient.Interface {
+	return nil
+}
+
+func (c *FakeDiscovery) WithLegacy() discovery.DiscoveryInterface {
+	panic("unimplemented")
+}

vendor/k8s.io/client-go/discovery/helper.go

@@ -0,0 +1,146 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package discovery
+
+import (
+	"fmt"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/sets"
+	apimachineryversion "k8s.io/apimachinery/pkg/version"
+)
+
+// IsResourceEnabled queries the server to determine if the resource specified is present on the server.
+// This is particularly helpful when writing a controller or an e2e test that requires a particular resource to function.
+func IsResourceEnabled(client DiscoveryInterface, resourceToCheck schema.GroupVersionResource) (bool, error) {
+	// this is a single request.  The ServerResourcesForGroupVersion handles the core v1 group as legacy.
+	resourceList, err := client.ServerResourcesForGroupVersion(resourceToCheck.GroupVersion().String())
+	if apierrors.IsNotFound(err) { // if the discovery endpoint isn't present, then the resource isn't present.
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	for _, actualResource := range resourceList.APIResources {
+		if actualResource.Name == resourceToCheck.Resource {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+// MatchesServerVersion queries the server to compares the build version
+// (git hash) of the client with the server's build version. It returns an error
+// if it failed to contact the server or if the versions are not an exact match.
+func MatchesServerVersion(clientVersion apimachineryversion.Info, client DiscoveryInterface) error {
+	sVer, err := client.ServerVersion()
+	if err != nil {
+		return fmt.Errorf("couldn't read version from server: %v", err)
+	}
+	// GitVersion includes GitCommit and GitTreeState, but best to be safe?
+	if clientVersion.GitVersion != sVer.GitVersion || clientVersion.GitCommit != sVer.GitCommit || clientVersion.GitTreeState != sVer.GitTreeState {
+		return fmt.Errorf("server version (%#v) differs from client version (%#v)", sVer, clientVersion)
+	}
+
+	return nil
+}
+
+// ServerSupportsVersion returns an error if the server doesn't have the required version
+func ServerSupportsVersion(client DiscoveryInterface, requiredGV schema.GroupVersion) error {
+	groups, err := client.ServerGroups()
+	if err != nil {
+		// This is almost always a connection error, and higher level code should treat this as a generic error,
+		// not a negotiation specific error.
+		return err
+	}
+	versions := metav1.ExtractGroupVersions(groups)
+	serverVersions := sets.String{}
+	for _, v := range versions {
+		serverVersions.Insert(v)
+	}
+
+	if serverVersions.Has(requiredGV.String()) {
+		return nil
+	}
+
+	// If the server supports no versions, then we should pretend it has the version because of old servers.
+	// This can happen because discovery fails due to 403 Forbidden errors
+	if len(serverVersions) == 0 {
+		return nil
+	}
+
+	return fmt.Errorf("server does not support API version %q", requiredGV)
+}
+
+// GroupVersionResources converts APIResourceLists to the GroupVersionResources.
+func GroupVersionResources(rls []*metav1.APIResourceList) (map[schema.GroupVersionResource]struct{}, error) {
+	gvrs := map[schema.GroupVersionResource]struct{}{}
+	for _, rl := range rls {
+		gv, err := schema.ParseGroupVersion(rl.GroupVersion)
+		if err != nil {
+			return nil, err
+		}
+		for i := range rl.APIResources {
+			gvrs[schema.GroupVersionResource{Group: gv.Group, Version: gv.Version, Resource: rl.APIResources[i].Name}] = struct{}{}
+		}
+	}
+	return gvrs, nil
+}
+
+// FilteredBy filters by the given predicate. Empty APIResourceLists are dropped.
+func FilteredBy(pred ResourcePredicate, rls []*metav1.APIResourceList) []*metav1.APIResourceList {
+	result := []*metav1.APIResourceList{}
+	for _, rl := range rls {
+		filtered := *rl
+		filtered.APIResources = nil
+		for i := range rl.APIResources {
+			if pred.Match(rl.GroupVersion, &rl.APIResources[i]) {
+				filtered.APIResources = append(filtered.APIResources, rl.APIResources[i])
+			}
+		}
+		if filtered.APIResources != nil {
+			result = append(result, &filtered)
+		}
+	}
+	return result
+}
+
+// ResourcePredicate has a method to check if a resource matches a given condition.
+type ResourcePredicate interface {
+	Match(groupVersion string, r *metav1.APIResource) bool
+}
+
+// ResourcePredicateFunc returns true if it matches a resource based on a custom condition.
+type ResourcePredicateFunc func(groupVersion string, r *metav1.APIResource) bool
+
+// Match is a wrapper around ResourcePredicateFunc.
+func (fn ResourcePredicateFunc) Match(groupVersion string, r *metav1.APIResource) bool {
+	return fn(groupVersion, r)
+}
+
+// SupportsAllVerbs is a predicate matching a resource iff all given verbs are supported.
+type SupportsAllVerbs struct {
+	Verbs []string
+}
+
+// Match checks if a resource contains all the given verbs.
+func (p SupportsAllVerbs) Match(groupVersion string, r *metav1.APIResource) bool {
+	return sets.NewString([]string(r.Verbs)...).HasAll(p.Verbs...)
+}