K8s: Set priority for aggregated discovery (#101427)

pkg/services/apiserver/builder/helper.go

@@ -245,6 +245,18 @@ func SetupConfig(
 
 	serverConfig.EffectiveVersion = v
 
+	// set priority for aggregated discovery
+	for i, b := range builders {
+		gvs := GetGroupVersions(b)
+		if len(gvs) == 0 {
+			return fmt.Errorf("builder did not return any API group versions: %T", b)
+		}
+		pvs := scheme.PrioritizedVersionsForGroup(gvs[0].Group)
+		for j, gv := range pvs {
+			serverConfig.AggregatedDiscoveryGroupManager.SetGroupVersionPriority(metav1.GroupVersion(gv), 15000+i, len(pvs)-j)
+		}
+	}
+
 	if err := AddPostStartHooks(serverConfig, builders); err != nil {
 		return err
 	}

pkg/services/apiserver/service.go

@@ -278,18 +278,21 @@ func (s *service) start(ctx context.Context) error {
 	groupVersions := make([]schema.GroupVersion, 0, len(builders))
 
 	// Install schemas
-	initialSize := len(kubeaggregator.APIVersionPriorities)
 	for i, b := range builders {
 		gvs := builder.GetGroupVersions(b)
 		groupVersions = append(groupVersions, gvs...)
+		if len(gvs) == 0 {
+			return fmt.Errorf("no group versions found for builder %T", b)
+		}
 		if err := b.InstallSchema(Scheme); err != nil {
 			return err
 		}
+		pvs := Scheme.PrioritizedVersionsForGroup(gvs[0].Group)
 
-		for _, gv := range gvs {
+		for j, gv := range pvs {
 			if s.features.IsEnabledGlobally(featuremgmt.FlagKubernetesAggregator) {
 				// set the priority for the group+version
-				kubeaggregator.APIVersionPriorities[gv] = kubeaggregator.Priority{Group: 15000, Version: int32(i + initialSize)}
+				kubeaggregator.APIVersionPriorities[gv] = kubeaggregator.Priority{Group: int32(15000 + i), Version: int32(len(pvs) - j)}
 			}
 
 			if a, ok := b.(builder.APIGroupAuthorizer); ok {