Merge pull request #116770 from alexzielenski/agg-discovery-err-sources

Fix aggregated discovery race when using CRD and Aggregated APIService under same group

Kubernetes-commit: 8dd3807f4df05abae4a440e0b21750e30bcdd1d3

pkg/endpoints/discovery/aggregated/fake.go

@@ -169,3 +169,7 @@ func (f *recorderResourceManager) WebService() *restful.WebService {
 func (f *recorderResourceManager) ServeHTTP(http.ResponseWriter, *http.Request) {
 	panic("unimplemented")
 }
+
+func (f *recorderResourceManager) WithSource(source Source) ResourceManager {
+	panic("unimplemented")
+}

pkg/endpoints/discovery/aggregated/handler.go

@@ -36,6 +36,15 @@ import (
 	"k8s.io/klog/v2"
 )
 
+type Source uint
+
+// The GroupVersion from the lowest Source takes precedence
+const (
+	AggregatorSource Source = 0
+	BuiltinSource    Source = 100
+	CRDSource        Source = 200
+)
+
 // This handler serves the /apis endpoint for an aggregated list of
 // api resources indexed by their group version.
 type ResourceManager interface {
@@ -65,9 +74,55 @@ type ResourceManager interface {
 	// Thread-Safe
 	SetGroups([]apidiscoveryv2beta1.APIGroupDiscovery)
 
+	// Returns the same resource manager using a different source
+	// The source is used to decide how to de-duplicate groups.
+	// The group from the least-numbered source is used
+	WithSource(source Source) ResourceManager
+
 	http.Handler
 }
 
+type resourceManager struct {
+	source Source
+	*resourceDiscoveryManager
+}
+
+func (rm resourceManager) AddGroupVersion(groupName string, value apidiscoveryv2beta1.APIVersionDiscovery) {
+	rm.resourceDiscoveryManager.AddGroupVersion(rm.source, groupName, value)
+}
+func (rm resourceManager) SetGroupVersionPriority(gv metav1.GroupVersion, grouppriority, versionpriority int) {
+	rm.resourceDiscoveryManager.SetGroupVersionPriority(rm.source, gv, grouppriority, versionpriority)
+}
+func (rm resourceManager) RemoveGroup(groupName string) {
+	rm.resourceDiscoveryManager.RemoveGroup(rm.source, groupName)
+}
+func (rm resourceManager) RemoveGroupVersion(gv metav1.GroupVersion) {
+	rm.resourceDiscoveryManager.RemoveGroupVersion(rm.source, gv)
+}
+func (rm resourceManager) SetGroups(groups []apidiscoveryv2beta1.APIGroupDiscovery) {
+	rm.resourceDiscoveryManager.SetGroups(rm.source, groups)
+}
+
+func (rm resourceManager) WithSource(source Source) ResourceManager {
+	return resourceManager{
+		source:                   source,
+		resourceDiscoveryManager: rm.resourceDiscoveryManager,
+	}
+}
+
+type groupKey struct {
+	name string
+
+	// Source identifies where this group came from and dictates which group
+	// among duplicates is chosen to be used for discovery.
+	source Source
+}
+
+type groupVersionKey struct {
+	metav1.GroupVersion
+	source Source
+}
+
 type resourceDiscoveryManager struct {
 	serializer runtime.NegotiatedSerializer
 	// cache is an atomic pointer to avoid the use of locks
@@ -78,8 +133,8 @@ type resourceDiscoveryManager struct {
 	// Writes protected by the lock.
 	// List of all apigroups & resources indexed by the resource manager
 	lock              sync.RWMutex
-	apiGroups         map[string]*apidiscoveryv2beta1.APIGroupDiscovery
+	apiGroups         map[groupKey]*apidiscoveryv2beta1.APIGroupDiscovery
-	versionPriorities map[metav1.GroupVersion]priorityInfo
+	versionPriorities map[groupVersionKey]priorityInfo
 }
 
 type priorityInfo struct {
@@ -93,7 +148,7 @@ func NewResourceManager(path string) ResourceManager {
 	utilruntime.Must(apidiscoveryv2beta1.AddToScheme(scheme))
 	rdm := &resourceDiscoveryManager{
 		serializer:        codecs,
-		versionPriorities: make(map[metav1.GroupVersion]priorityInfo),
+		versionPriorities: make(map[groupVersionKey]priorityInfo),
 	}
 	rdm.serveHTTPFunc = metrics.InstrumentHandlerFunc("GET",
 		/* group = */ "",
@@ -105,20 +160,28 @@ func NewResourceManager(path string) ResourceManager {
 		/* deprecated */ false,
 		/* removedRelease */ "",
 		rdm.serveHTTP)
-	return rdm
+	return resourceManager{
+		source:                   BuiltinSource,
+		resourceDiscoveryManager: rdm,
+	}
 }
-func (rdm *resourceDiscoveryManager) SetGroupVersionPriority(gv metav1.GroupVersion, groupPriorityMinimum, versionPriority int) {
+
+func (rdm *resourceDiscoveryManager) SetGroupVersionPriority(source Source, gv metav1.GroupVersion, groupPriorityMinimum, versionPriority int) {
 	rdm.lock.Lock()
 	defer rdm.lock.Unlock()
 
-	rdm.versionPriorities[gv] = priorityInfo{
+	key := groupVersionKey{
+		GroupVersion: gv,
+		source:       source,
+	}
+	rdm.versionPriorities[key] = priorityInfo{
 		GroupPriorityMinimum: groupPriorityMinimum,
 		VersionPriority:      versionPriority,
 	}
 	rdm.cache.Store(nil)
 }
 
-func (rdm *resourceDiscoveryManager) SetGroups(groups []apidiscoveryv2beta1.APIGroupDiscovery) {
+func (rdm *resourceDiscoveryManager) SetGroups(source Source, groups []apidiscoveryv2beta1.APIGroupDiscovery) {
 	rdm.lock.Lock()
 	defer rdm.lock.Unlock()
 
@@ -127,13 +190,17 @@ func (rdm *resourceDiscoveryManager) SetGroups(groups []apidiscoveryv2beta1.APIG
 
 	for _, group := range groups {
 		for _, version := range group.Versions {
-			rdm.addGroupVersionLocked(group.Name, version)
+			rdm.addGroupVersionLocked(source, group.Name, version)
 		}
 	}
 
 	// Filter unused out priority entries
 	for gv := range rdm.versionPriorities {
-		entry, exists := rdm.apiGroups[gv.Group]
+		key := groupKey{
+			source: source,
+			name:   gv.Group,
+		}
+		entry, exists := rdm.apiGroups[key]
 		if !exists {
 			delete(rdm.versionPriorities, gv)
 			continue
@@ -154,21 +221,26 @@ func (rdm *resourceDiscoveryManager) SetGroups(groups []apidiscoveryv2beta1.APIG
 	}
 }
 
-func (rdm *resourceDiscoveryManager) AddGroupVersion(groupName string, value apidiscoveryv2beta1.APIVersionDiscovery) {
+func (rdm *resourceDiscoveryManager) AddGroupVersion(source Source, groupName string, value apidiscoveryv2beta1.APIVersionDiscovery) {
 	rdm.lock.Lock()
 	defer rdm.lock.Unlock()
 
-	rdm.addGroupVersionLocked(groupName, value)
+	rdm.addGroupVersionLocked(source, groupName, value)
 }
 
-func (rdm *resourceDiscoveryManager) addGroupVersionLocked(groupName string, value apidiscoveryv2beta1.APIVersionDiscovery) {
+func (rdm *resourceDiscoveryManager) addGroupVersionLocked(source Source, groupName string, value apidiscoveryv2beta1.APIVersionDiscovery) {
 	klog.Infof("Adding GroupVersion %s %s to ResourceManager", groupName, value.Version)
 
 	if rdm.apiGroups == nil {
-		rdm.apiGroups = make(map[string]*apidiscoveryv2beta1.APIGroupDiscovery)
+		rdm.apiGroups = make(map[groupKey]*apidiscoveryv2beta1.APIGroupDiscovery)
 	}
 
-	if existing, groupExists := rdm.apiGroups[groupName]; groupExists {
+	key := groupKey{
+		source: source,
+		name:   groupName,
+	}
+
+	if existing, groupExists := rdm.apiGroups[key]; groupExists {
 		// If this version already exists, replace it
 		versionExists := false
 
@@ -181,6 +253,7 @@ func (rdm *resourceDiscoveryManager) addGroupVersionLocked(groupName string, val
 				if reflect.DeepEqual(existing.Versions[i], value) {
 					return
 				}
+
 				existing.Versions[i] = value
 				versionExists = true
 				break
@@ -198,12 +271,16 @@ func (rdm *resourceDiscoveryManager) addGroupVersionLocked(groupName string, val
 			},
 			Versions: []apidiscoveryv2beta1.APIVersionDiscovery{value},
 		}
-		rdm.apiGroups[groupName] = group
+		rdm.apiGroups[key] = group
 	}
 
 	gv := metav1.GroupVersion{Group: groupName, Version: value.Version}
-	if _, ok := rdm.versionPriorities[gv]; !ok {
+	gvKey := groupVersionKey{
-		rdm.versionPriorities[gv] = priorityInfo{
+		GroupVersion: gv,
+		source:       source,
+	}
+	if _, ok := rdm.versionPriorities[gvKey]; !ok {
+		rdm.versionPriorities[gvKey] = priorityInfo{
 			GroupPriorityMinimum: 1000,
 			VersionPriority:      15,
 		}
@@ -213,10 +290,16 @@ func (rdm *resourceDiscoveryManager) addGroupVersionLocked(groupName string, val
 	rdm.cache.Store(nil)
 }
 
-func (rdm *resourceDiscoveryManager) RemoveGroupVersion(apiGroup metav1.GroupVersion) {
+func (rdm *resourceDiscoveryManager) RemoveGroupVersion(source Source, apiGroup metav1.GroupVersion) {
 	rdm.lock.Lock()
 	defer rdm.lock.Unlock()
-	group, exists := rdm.apiGroups[apiGroup.Group]
+
+	key := groupKey{
+		source: source,
+		name:   apiGroup.Group,
+	}
+
+	group, exists := rdm.apiGroups[key]
 	if !exists {
 		return
 	}
@@ -234,23 +317,33 @@ func (rdm *resourceDiscoveryManager) RemoveGroupVersion(apiGroup metav1.GroupVer
 		return
 	}
 
-	delete(rdm.versionPriorities, apiGroup)
+	gvKey := groupVersionKey{
+		GroupVersion: apiGroup,
+		source:       source,
+	}
+
+	delete(rdm.versionPriorities, gvKey)
 	if len(group.Versions) == 0 {
-		delete(rdm.apiGroups, group.Name)
+		delete(rdm.apiGroups, key)
 	}
 
 	// Reset response document so it is recreated lazily
 	rdm.cache.Store(nil)
 }
 
-func (rdm *resourceDiscoveryManager) RemoveGroup(groupName string) {
+func (rdm *resourceDiscoveryManager) RemoveGroup(source Source, groupName string) {
 	rdm.lock.Lock()
 	defer rdm.lock.Unlock()
 
-	delete(rdm.apiGroups, groupName)
+	key := groupKey{
+		source: source,
+		name:   groupName,
+	}
+
+	delete(rdm.apiGroups, key)
 
 	for k := range rdm.versionPriorities {
-		if k.Group == groupName {
+		if k.Group == groupName && k.source == source {
 			delete(rdm.versionPriorities, k)
 		}
 	}
@@ -265,17 +358,63 @@ func (rdm *resourceDiscoveryManager) calculateAPIGroupsLocked() []apidiscoveryv2
 	regenerationCounter.Inc()
 	// Re-order the apiGroups by their priority.
 	groups := []apidiscoveryv2beta1.APIGroupDiscovery{}
-	for _, group := range rdm.apiGroups {
+
-		copied := *group.DeepCopy()
+	groupsToUse := map[string]apidiscoveryv2beta1.APIGroupDiscovery{}
+	sourcesUsed := map[metav1.GroupVersion]Source{}
+
+	for key, group := range rdm.apiGroups {
+		if existing, ok := groupsToUse[key.name]; ok {
+			for _, v := range group.Versions {
+				gv := metav1.GroupVersion{Group: key.name, Version: v.Version}
+
+				// Skip groupversions we've already seen before. Only DefaultSource
+				// takes precedence
+				if usedSource, seen := sourcesUsed[gv]; seen && key.source >= usedSource {
+					continue
+				} else if seen {
+					// Find the index of the duplicate version and replace
+					for i := 0; i < len(existing.Versions); i++ {
+						if existing.Versions[i].Version == v.Version {
+							existing.Versions[i] = v
+							break
+						}
+					}
+
+				} else {
+					// New group-version, just append
+					existing.Versions = append(existing.Versions, v)
+				}
+
+				sourcesUsed[gv] = key.source
+				groupsToUse[key.name] = existing
+			}
+			// Check to see if we have overlapping versions. If we do, take the one
+			// with highest source precedence
+		} else {
+			groupsToUse[key.name] = *group.DeepCopy()
+			for _, v := range group.Versions {
+				gv := metav1.GroupVersion{Group: key.name, Version: v.Version}
+				sourcesUsed[gv] = key.source
+			}
+		}
+	}
+
+	for _, group := range groupsToUse {
 
 		// Re-order versions based on their priority. Use kube-aware string
 		// comparison as a tie breaker
-		sort.SliceStable(copied.Versions, func(i, j int) bool {
+		sort.SliceStable(group.Versions, func(i, j int) bool {
-			iVersion := copied.Versions[i].Version
+			iVersion := group.Versions[i].Version
-			jVersion := copied.Versions[j].Version
+			jVersion := group.Versions[j].Version
 
-			iPriority := rdm.versionPriorities[metav1.GroupVersion{Group: group.Name, Version: iVersion}].VersionPriority
+			iGV := metav1.GroupVersion{Group: group.Name, Version: iVersion}
-			jPriority := rdm.versionPriorities[metav1.GroupVersion{Group: group.Name, Version: jVersion}].VersionPriority
+			jGV := metav1.GroupVersion{Group: group.Name, Version: jVersion}
+
+			iSource := sourcesUsed[iGV]
+			jSource := sourcesUsed[jGV]
+
+			iPriority := rdm.versionPriorities[groupVersionKey{iGV, iSource}].VersionPriority
+			jPriority := rdm.versionPriorities[groupVersionKey{jGV, jSource}].VersionPriority
 
 			// Sort by version string comparator if priority is equal
 			if iPriority == jPriority {
@@ -286,13 +425,16 @@ func (rdm *resourceDiscoveryManager) calculateAPIGroupsLocked() []apidiscoveryv2
 			return iPriority > jPriority
 		})
 
-		groups = append(groups, *copied.DeepCopy())
+		groups = append(groups, group)
-
 	}
 
 	// For each group, determine the highest minimum group priority and use that
 	priorities := map[string]int{}
 	for gv, info := range rdm.versionPriorities {
+		if source := sourcesUsed[gv.GroupVersion]; source != gv.source {
+			continue
+		}
+
 		if existing, exists := priorities[gv.Group]; exists {
 			if existing < info.GroupPriorityMinimum {
 				priorities[gv.Group] = info.GroupPriorityMinimum

pkg/endpoints/discovery/aggregated/handler_test.go

@@ -18,6 +18,7 @@ package aggregated_test
 
 import (
 	"encoding/json"
+	"fmt"
 	"math/rand"
 	"net/http"
 	"net/http/httptest"
@@ -365,6 +366,91 @@ func TestUpdateService(t *testing.T) {
 	assert.NotEqual(t, secondDocument, initialDocument, "should have returned expected document")
 }
 
+func TestMultipleSources(t *testing.T) {
+	type pair struct {
+		manager discoveryendpoint.ResourceManager
+		apis    apidiscoveryv2beta1.APIGroupDiscoveryList
+	}
+
+	pairs := []pair{}
+
+	defaultManager := discoveryendpoint.NewResourceManager("apis")
+	for i := 0; i < 10; i++ {
+		name := discoveryendpoint.Source(100 * i)
+		manager := defaultManager.WithSource(name)
+		apis := fuzzAPIGroups(1, 3, int64(15+i))
+
+		// Give the groups deterministic names
+		for i := range apis.Items {
+			apis.Items[i].Name = fmt.Sprintf("%v.%v.com", i, name)
+		}
+
+		pairs = append(pairs, pair{manager, apis})
+	}
+
+	expectedResult := []apidiscoveryv2beta1.APIGroupDiscovery{}
+
+	groupCounter := 0
+	for _, p := range pairs {
+		for gi, g := range p.apis.Items {
+			for vi, v := range g.Versions {
+				p.manager.AddGroupVersion(g.Name, v)
+
+				// Use index for priority so we dont have to do any sorting
+				// Use negative index since it is sorted descending
+				p.manager.SetGroupVersionPriority(metav1.GroupVersion{Group: g.Name, Version: v.Version}, -gi-groupCounter, -vi)
+			}
+
+			expectedResult = append(expectedResult, g)
+		}
+
+		groupCounter += len(p.apis.Items)
+	}
+
+	// Show discovery document is what we expect
+	_, _, initialDocument := fetchPath(defaultManager, "application/json", discoveryPath, "")
+
+	require.Len(t, initialDocument.Items, len(expectedResult))
+	require.Equal(t, initialDocument.Items, expectedResult)
+}
+
+// Shows that if you have multiple sources including Default source using
+// with the same group name the groups added by the "Default" source are used
+func TestSourcePrecedence(t *testing.T) {
+	defaultManager := discoveryendpoint.NewResourceManager("apis")
+	otherManager := defaultManager.WithSource(500)
+	apis := fuzzAPIGroups(1, 3, int64(15))
+	for _, g := range apis.Items {
+		for i, v := range g.Versions {
+			v.Freshness = apidiscoveryv2beta1.DiscoveryFreshnessCurrent
+			g.Versions[i] = v
+			otherManager.AddGroupVersion(g.Name, v)
+		}
+	}
+
+	_, _, initialDocument := fetchPath(defaultManager, "application/json", discoveryPath, "")
+	require.Equal(t, apis.Items, initialDocument.Items)
+
+	// Add the first groupversion under default.
+	// No versions should appear in discovery document except this one
+	overrideVersion := initialDocument.Items[0].Versions[0]
+	overrideVersion.Freshness = apidiscoveryv2beta1.DiscoveryFreshnessStale
+	defaultManager.AddGroupVersion(initialDocument.Items[0].Name, overrideVersion)
+
+	_, _, maskedDocument := fetchPath(defaultManager, "application/json", discoveryPath, "")
+	masked := initialDocument.DeepCopy()
+	masked.Items[0].Versions[0].Freshness = apidiscoveryv2beta1.DiscoveryFreshnessStale
+
+	require.Equal(t, masked.Items, maskedDocument.Items)
+
+	// Wipe out default group. The other versions from the other group should now
+	// appear since the group is not being overridden by defaults ource
+	defaultManager.RemoveGroup(apis.Items[0].Name)
+
+	_, _, resetDocument := fetchPath(defaultManager, "application/json", discoveryPath, "")
+	require.Equal(t, resetDocument.Items, initialDocument.Items)
+}
+
 // Show the discovery manager is capable of serving requests to multiple users
 // with unchanging data
 func TestConcurrentRequests(t *testing.T) {

pkg/server/genericapiserver.go

@@ -776,6 +776,7 @@ func (s *GenericAPIServer) installAPIResources(apiPrefix string, apiGroupInfo *A
 				s.AggregatedDiscoveryGroupManager.AddGroupVersion(
 					groupVersion.Group,
 					apidiscoveryv2beta1.APIVersionDiscovery{
+						Freshness: apidiscoveryv2beta1.DiscoveryFreshnessCurrent,
 						Version:   groupVersion.Version,
 						Resources: discoveryAPIResources,
 					},
@@ -785,6 +786,7 @@ func (s *GenericAPIServer) installAPIResources(apiPrefix string, apiGroupInfo *A
 				s.AggregatedLegacyDiscoveryGroupManager.AddGroupVersion(
 					groupVersion.Group,
 					apidiscoveryv2beta1.APIVersionDiscovery{
+						Freshness: apidiscoveryv2beta1.DiscoveryFreshnessCurrent,
 						Version:   groupVersion.Version,
 						Resources: discoveryAPIResources,
 					},