Merge pull request #129081 from stlaz/fg_remote_uid

featuregate UID in RequestHeader authenticator

pkg/controlplane/controller/clusterauthenticationtrust/cluster_authentication_trust_controller.go

@@ -35,7 +35,9 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apiserver/pkg/authentication/request/headerrequest"
+	"k8s.io/apiserver/pkg/features"
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	corev1informers "k8s.io/client-go/informers/core/v1"
 	"k8s.io/client-go/kubernetes"
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
@@ -262,10 +264,13 @@ func getConfigMapDataFor(authenticationInfo ClusterAuthenticationInfo) (map[stri
 		if err != nil {
 			return nil, err
 		}
-		data["requestheader-uid-headers"], err = jsonSerializeStringSlice(authenticationInfo.RequestHeaderUIDHeaders.Value())
+		if utilfeature.DefaultFeatureGate.Enabled(features.RemoteRequestHeaderUID) && len(authenticationInfo.RequestHeaderUIDHeaders.Value()) > 0 {
-		if err != nil {
+			data["requestheader-uid-headers"], err = jsonSerializeStringSlice(authenticationInfo.RequestHeaderUIDHeaders.Value())
-			return nil, err
+			if err != nil {
+				return nil, err
+			}
 		}
+
 		data["requestheader-group-headers"], err = jsonSerializeStringSlice(authenticationInfo.RequestHeaderGroupHeaders.Value())
 		if err != nil {
 			return nil, err
@@ -305,9 +310,12 @@ func getClusterAuthenticationInfoFor(data map[string]string) (ClusterAuthenticat
 	if err != nil {
 		return ClusterAuthenticationInfo{}, err
 	}
-	ret.RequestHeaderUIDHeaders, err = jsonDeserializeStringSlice(data["requestheader-uid-headers"])
+
-	if err != nil {
+	if utilfeature.DefaultFeatureGate.Enabled(features.RemoteRequestHeaderUID) {
-		return ClusterAuthenticationInfo{}, err
+		ret.RequestHeaderUIDHeaders, err = jsonDeserializeStringSlice(data["requestheader-uid-headers"])
+		if err != nil {
+			return ClusterAuthenticationInfo{}, err
+		}
 	}
 
 	if caBundle := data["requestheader-client-ca-file"]; len(caBundle) > 0 {

pkg/controlplane/controller/clusterauthenticationtrust/cluster_authentication_trust_controller_test.go

@@ -30,11 +30,14 @@ import (
 	"k8s.io/apimachinery/pkg/util/dump"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	"k8s.io/apiserver/pkg/authentication/request/headerrequest"
+	"k8s.io/apiserver/pkg/features"
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/kubernetes/fake"
 	corev1listers "k8s.io/client-go/listers/core/v1"
 	clienttesting "k8s.io/client-go/testing"
 	"k8s.io/client-go/tools/cache"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 )
 
 var (
@@ -95,6 +98,7 @@ func TestWriteClientCAs(t *testing.T) {
 		preexistingObjs    []runtime.Object
 		expectedConfigMaps map[string]*corev1.ConfigMap
 		expectCreate       bool
+		uidGate            bool
 	}{
 		{
 			name: "basic",
@@ -107,6 +111,32 @@ func TestWriteClientCAs(t *testing.T) {
 				RequestHeaderCA:                  anotherRandomCAProvider,
 				RequestHeaderAllowedNames:        headerrequest.StaticStringSlice{"first", "second"},
 			},
+			expectedConfigMaps: map[string]*corev1.ConfigMap{
+				"extension-apiserver-authentication": {
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"client-ca-file":                     string(someRandomCA),
+						"requestheader-username-headers":     `["alfa","bravo","charlie"]`,
+						"requestheader-group-headers":        `["delta"]`,
+						"requestheader-extra-headers-prefix": `["echo","foxtrot"]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `["first","second"]`,
+					},
+				},
+			},
+			expectCreate: true,
+		},
+		{
+			name: "basic with feature gate",
+			clusterAuthInfo: ClusterAuthenticationInfo{
+				ClientCA:                         someRandomCAProvider,
+				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{"alfa", "bravo", "charlie"},
+				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{"golf", "hotel", "india"},
+				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{"delta"},
+				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{"echo", "foxtrot"},
+				RequestHeaderCA:                  anotherRandomCAProvider,
+				RequestHeaderAllowedNames:        headerrequest.StaticStringSlice{"first", "second"},
+			},
 			expectedConfigMaps: map[string]*corev1.ConfigMap{
 				"extension-apiserver-authentication": {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
@@ -122,6 +152,7 @@ func TestWriteClientCAs(t *testing.T) {
 				},
 			},
 			expectCreate: true,
+			uidGate:      true,
 		},
 		{
 			name: "skip extension-apiserver-authentication",
@@ -134,7 +165,6 @@ func TestWriteClientCAs(t *testing.T) {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 					Data: map[string]string{
 						"requestheader-username-headers":     `[]`,
-						"requestheader-uid-headers":          `[]`,
 						"requestheader-group-headers":        `[]`,
 						"requestheader-extra-headers-prefix": `[]`,
 						"requestheader-client-ca-file":       string(anotherRandomCA),
@@ -169,7 +199,6 @@ func TestWriteClientCAs(t *testing.T) {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 					Data: map[string]string{
 						"requestheader-username-headers":     `[]`,
-						"requestheader-uid-headers":          `[]`,
 						"requestheader-group-headers":        `[]`,
 						"requestheader-extra-headers-prefix": `[]`,
 						"requestheader-client-ca-file":       string(anotherRandomCA),
@@ -205,7 +234,6 @@ func TestWriteClientCAs(t *testing.T) {
 			name: "overwrite extension-apiserver-authentication requestheader",
 			clusterAuthInfo: ClusterAuthenticationInfo{
 				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{},
-				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{},
 				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{},
 				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{},
 				RequestHeaderCA:                  anotherRandomCAProvider,
@@ -216,7 +244,6 @@ func TestWriteClientCAs(t *testing.T) {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 					Data: map[string]string{
 						"requestheader-username-headers":     `[]`,
-						"requestheader-uid-headers":          `[]`,
 						"requestheader-group-headers":        `[]`,
 						"requestheader-extra-headers-prefix": `[]`,
 						"requestheader-client-ca-file":       string(someRandomCA),
@@ -229,7 +256,6 @@ func TestWriteClientCAs(t *testing.T) {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 					Data: map[string]string{
 						"requestheader-username-headers":     `[]`,
-						"requestheader-uid-headers":          `[]`,
 						"requestheader-group-headers":        `[]`,
 						"requestheader-extra-headers-prefix": `[]`,
 						"requestheader-client-ca-file":       string(someRandomCA) + string(anotherRandomCA),
@@ -260,7 +286,6 @@ func TestWriteClientCAs(t *testing.T) {
 			name: "skip on no change",
 			clusterAuthInfo: ClusterAuthenticationInfo{
 				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{},
-				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{},
 				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{},
 				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{},
 				RequestHeaderCA:                  anotherRandomCAProvider,
@@ -271,7 +296,6 @@ func TestWriteClientCAs(t *testing.T) {
 					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 					Data: map[string]string{
 						"requestheader-username-headers":     `[]`,
-						"requestheader-uid-headers":          `[]`,
 						"requestheader-group-headers":        `[]`,
 						"requestheader-extra-headers-prefix": `[]`,
 						"requestheader-client-ca-file":       string(anotherRandomCA),
@@ -282,10 +306,126 @@ func TestWriteClientCAs(t *testing.T) {
 			expectedConfigMaps: map[string]*corev1.ConfigMap{},
 			expectCreate:       false,
 		},
+		{
+			name: "drop uid without feature gate",
+			clusterAuthInfo: ClusterAuthenticationInfo{
+				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{},
+				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{"panda"},
+				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{},
+				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{},
+				RequestHeaderCA:                  anotherRandomCAProvider,
+				RequestHeaderAllowedNames:        headerrequest.StaticStringSlice{},
+			},
+			preexistingObjs: []runtime.Object{
+				&corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-uid-headers":          `["snorlax"]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectedConfigMaps: map[string]*corev1.ConfigMap{
+				"extension-apiserver-authentication": {
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectCreate: false,
+		},
+		{
+			name: "add uid with feature gate",
+			clusterAuthInfo: ClusterAuthenticationInfo{
+				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{},
+				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{"panda"},
+				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{},
+				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{},
+				RequestHeaderCA:                  anotherRandomCAProvider,
+				RequestHeaderAllowedNames:        headerrequest.StaticStringSlice{},
+			},
+			preexistingObjs: []runtime.Object{
+				&corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectedConfigMaps: map[string]*corev1.ConfigMap{
+				"extension-apiserver-authentication": {
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-uid-headers":          `["panda"]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectCreate: false,
+			uidGate:      true,
+		},
+		{
+			name: "append uid with feature gate",
+			clusterAuthInfo: ClusterAuthenticationInfo{
+				RequestHeaderUsernameHeaders:     headerrequest.StaticStringSlice{},
+				RequestHeaderUIDHeaders:          headerrequest.StaticStringSlice{"panda"},
+				RequestHeaderGroupHeaders:        headerrequest.StaticStringSlice{},
+				RequestHeaderExtraHeaderPrefixes: headerrequest.StaticStringSlice{},
+				RequestHeaderCA:                  anotherRandomCAProvider,
+				RequestHeaderAllowedNames:        headerrequest.StaticStringSlice{},
+			},
+			preexistingObjs: []runtime.Object{
+				&corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-uid-headers":          `["snorlax"]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectedConfigMaps: map[string]*corev1.ConfigMap{
+				"extension-apiserver-authentication": {
+					ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
+					Data: map[string]string{
+						"requestheader-username-headers":     `[]`,
+						"requestheader-uid-headers":          `["snorlax","panda"]`,
+						"requestheader-group-headers":        `[]`,
+						"requestheader-extra-headers-prefix": `[]`,
+						"requestheader-client-ca-file":       string(anotherRandomCA),
+						"requestheader-allowed-names":        `[]`,
+					},
+				},
+			},
+			expectCreate: false,
+			uidGate:      true,
+		},
 	}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
+			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.RemoteRequestHeaderUID, test.uidGate)
+
 			client := fake.NewSimpleClientset(test.preexistingObjs...)
 			configMapIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
 			for _, obj := range test.preexistingObjs {
@@ -341,7 +481,6 @@ func TestWriteConfigMapDeleted(t *testing.T) {
 		ObjectMeta: metav1.ObjectMeta{Namespace: metav1.NamespaceSystem, Name: "extension-apiserver-authentication"},
 		Data: map[string]string{
 			"requestheader-username-headers":     `[]`,
-			"requestheader-uid-headers":          `[]`,
 			"requestheader-group-headers":        `[]`,
 			"requestheader-extra-headers-prefix": `[]`,
 			"requestheader-client-ca-file":       string(anotherRandomCA),

pkg/features/versioned_kube_features.go

@@ -306,6 +306,10 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 		{Version: version.MustParse("1.29"), Default: true, PreRelease: featuregate.GA, LockToDefault: true},
 	},
 
+	genericfeatures.RemoteRequestHeaderUID: {
+		{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
+	},
+
 	genericfeatures.ResilientWatchCacheInitialization: {
 		{Version: version.MustParse("1.31"), Default: true, PreRelease: featuregate.Beta},
 	},

staging/src/k8s.io/apiserver/pkg/features/kube_features.go

@@ -149,6 +149,13 @@ const (
 	// to a chunking list request.
 	RemainingItemCount featuregate.Feature = "RemainingItemCount"
 
+	// owner: @stlaz
+	//
+	// Enable kube-apiserver to accept UIDs via request header authentication.
+	// This will also make the kube-apiserver's API aggregator add UIDs via standard
+	// headers when forwarding requests to the servers serving the aggregated API.
+	RemoteRequestHeaderUID featuregate.Feature = "RemoteRequestHeaderUID"
+
 	// owner: @wojtek-t
 	//
 	// Enables resilient watchcache initialization to avoid controlplane
@@ -359,6 +366,10 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 		{Version: version.MustParse("1.29"), Default: true, PreRelease: featuregate.GA, LockToDefault: true},
 	},
 
+	RemoteRequestHeaderUID: {
+		{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
+	},
+
 	ResilientWatchCacheInitialization: {
 		{Version: version.MustParse("1.31"), Default: true, PreRelease: featuregate.Beta},
 	},

staging/src/k8s.io/apiserver/pkg/server/options/authentication.go

@@ -29,8 +29,10 @@ import (
 	"k8s.io/apiserver/pkg/apis/apiserver"
 	"k8s.io/apiserver/pkg/authentication/authenticatorfactory"
 	"k8s.io/apiserver/pkg/authentication/request/headerrequest"
+	"k8s.io/apiserver/pkg/features"
 	"k8s.io/apiserver/pkg/server"
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -68,9 +70,6 @@ func (s *RequestHeaderAuthenticationOptions) Validate() []error {
 	if err := checkForWhiteSpaceOnly("requestheader-username-headers", s.UsernameHeaders...); err != nil {
 		allErrors = append(allErrors, err)
 	}
-	if err := checkForWhiteSpaceOnly("requestheader-uid-headers", s.UIDHeaders...); err != nil {
-		allErrors = append(allErrors, err)
-	}
 	if err := checkForWhiteSpaceOnly("requestheader-group-headers", s.GroupHeaders...); err != nil {
 		allErrors = append(allErrors, err)
 	}
@@ -84,10 +83,6 @@ func (s *RequestHeaderAuthenticationOptions) Validate() []error {
 	if len(s.UsernameHeaders) > 0 && !caseInsensitiveHas(s.UsernameHeaders, "X-Remote-User") {
 		klog.Warningf("--requestheader-username-headers is set without specifying the standard X-Remote-User header - API aggregation will not work")
 	}
-	if len(s.UIDHeaders) > 0 && !caseInsensitiveHas(s.UIDHeaders, "X-Remote-Uid") {
-		// this was added later and so we are able to error out
-		allErrors = append(allErrors, fmt.Errorf("--requestheader-uid-headers is set without specifying the standard X-Remote-Uid header - API aggregation will not work"))
-	}
 	if len(s.GroupHeaders) > 0 && !caseInsensitiveHas(s.GroupHeaders, "X-Remote-Group") {
 		klog.Warningf("--requestheader-group-headers is set without specifying the standard X-Remote-Group header - API aggregation will not work")
 	}
@@ -95,6 +90,20 @@ func (s *RequestHeaderAuthenticationOptions) Validate() []error {
 		klog.Warningf("--requestheader-extra-headers-prefix is set without specifying the standard X-Remote-Extra- header prefix - API aggregation will not work")
 	}
 
+	if !utilfeature.DefaultFeatureGate.Enabled(features.RemoteRequestHeaderUID) {
+		if len(s.UIDHeaders) > 0 {
+			allErrors = append(allErrors, fmt.Errorf("--requestheader-uid-headers requires the %q feature to be enabled", features.RemoteRequestHeaderUID))
+		}
+	} else {
+		if err := checkForWhiteSpaceOnly("requestheader-uid-headers", s.UIDHeaders...); err != nil {
+			allErrors = append(allErrors, err)
+		}
+		if len(s.UIDHeaders) > 0 && !caseInsensitiveHas(s.UIDHeaders, "X-Remote-Uid") {
+			// this was added later and so we are able to error out
+			allErrors = append(allErrors, fmt.Errorf("--requestheader-uid-headers is set without specifying the standard X-Remote-Uid header - API aggregation will not work"))
+		}
+	}
+
 	return allErrors
 }
 
@@ -126,7 +135,7 @@ func (s *RequestHeaderAuthenticationOptions) AddFlags(fs *pflag.FlagSet) {
 		"List of request headers to inspect for usernames. X-Remote-User is common.")
 
 	fs.StringSliceVar(&s.UIDHeaders, "requestheader-uid-headers", s.UIDHeaders, ""+
-		"List of request headers to inspect for UIDs. X-Remote-Uid is suggested.")
+		"List of request headers to inspect for UIDs. X-Remote-Uid is suggested. Requires the RemoteRequestHeaderUID feature to be enabled.")
 
 	fs.StringSliceVar(&s.GroupHeaders, "requestheader-group-headers", s.GroupHeaders, ""+
 		"List of request headers to inspect for groups. X-Remote-Group is suggested.")

staging/src/k8s.io/component-base/featuregate/testing/feature_gate.go

@@ -99,7 +99,7 @@ func SetFeatureGateEmulationVersionDuringTest(tb TB, gate featuregate.FeatureGat
 	detectParallelOverrideCleanup := detectParallelOverrideEmulationVersion(tb, ver)
 	originalEmuVer := gate.(featuregate.MutableVersionedFeatureGate).EmulationVersion()
 	if err := gate.(featuregate.MutableVersionedFeatureGate).SetEmulationVersion(ver); err != nil {
-		tb.Fatalf("failed to set emulation version to %s during test", ver.String())
+		tb.Fatalf("failed to set emulation version to %s during test: %v", ver.String(), err)
 	}
 	tb.Cleanup(func() {
 		tb.Helper()

staging/src/k8s.io/kube-aggregator/pkg/apiserver/handler_proxy.go

@@ -159,7 +159,12 @@ func (r *proxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	proxyRoundTripper := handlingInfo.proxyRoundTripper
 	upgrade := httpstream.IsUpgradeRequest(req)
 
-	proxyRoundTripper = transport.NewAuthProxyRoundTripper(user.GetName(), user.GetUID(), user.GetGroups(), user.GetExtra(), proxyRoundTripper)
+	var userUID string
+	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.RemoteRequestHeaderUID) {
+		userUID = user.GetUID()
+	}
+
+	proxyRoundTripper = transport.NewAuthProxyRoundTripper(user.GetName(), userUID, user.GetGroups(), user.GetExtra(), proxyRoundTripper)
 
 	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.APIServerTracing) && !upgrade {
 		tracingWrapper := tracing.WrapperFor(r.tracerProvider)
@@ -170,7 +175,7 @@ func (r *proxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	// NOT use the proxyRoundTripper.  It's a direct dial that bypasses the proxyRoundTripper.  This means that we have to
 	// attach the "correct" user headers to the request ahead of time.
 	if upgrade {
-		transport.SetAuthProxyHeaders(newReq, user.GetName(), user.GetUID(), user.GetGroups(), user.GetExtra())
+		transport.SetAuthProxyHeaders(newReq, user.GetName(), userUID, user.GetGroups(), user.GetExtra())
 	}
 
 	handler := proxy.NewUpgradeAwareHandler(location, proxyRoundTripper, true, upgrade, &responder{w: w})

staging/src/k8s.io/kube-aggregator/pkg/apiserver/handler_proxy_test.go

@@ -34,31 +34,34 @@ import (
 	"sync/atomic"
 	"testing"
 
-	"k8s.io/apiserver/pkg/audit"
+	"github.com/google/go-cmp/cmp"
-	"k8s.io/apiserver/pkg/server/dynamiccertificates"
-	"k8s.io/client-go/transport"
-
-	"golang.org/x/net/websocket"
-
 	"go.opentelemetry.io/otel/propagation"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/sdk/trace/tracetest"
 	"go.opentelemetry.io/otel/trace"
+	"golang.org/x/net/websocket"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	utilnet "k8s.io/apimachinery/pkg/util/net"
 	"k8s.io/apimachinery/pkg/util/proxy"
 	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apiserver/pkg/audit"
 	"k8s.io/apiserver/pkg/authentication/user"
 	"k8s.io/apiserver/pkg/endpoints/filters"
 	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/features"
+	"k8s.io/apiserver/pkg/server/dynamiccertificates"
 	"k8s.io/apiserver/pkg/server/egressselector"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	utilflowcontrol "k8s.io/apiserver/pkg/util/flowcontrol"
 	apiserverproxyutil "k8s.io/apiserver/pkg/util/proxy"
+	"k8s.io/client-go/transport"
+	"k8s.io/component-base/featuregate"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 	"k8s.io/component-base/metrics"
 	"k8s.io/component-base/metrics/legacyregistry"
 	apiregistration "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1"
-	"k8s.io/utils/pointer"
 	"k8s.io/utils/ptr"
 )
 
@@ -130,6 +133,8 @@ func TestProxyHandler(t *testing.T) {
 		expectedBody       string
 		expectedCalled     bool
 		expectedHeaders    map[string][]string
+
+		enableFeatureGates []featuregate.Feature
 	}{
 		"no target": {
 			expectedStatusCode: http.StatusNotFound,
@@ -138,7 +143,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service: &apiregistration.ServiceReference{Port: pointer.Int32Ptr(443)},
+					Service: &apiregistration.ServiceReference{Port: ptr.To[int32](443)},
 					Group:   "foo",
 					Version: "v1",
 				},
@@ -161,7 +166,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service:               &apiregistration.ServiceReference{Port: pointer.Int32Ptr(443)},
+					Service:               &apiregistration.ServiceReference{Port: ptr.To[int32](443)},
 					Group:                 "foo",
 					Version:               "v1",
 					InsecureSkipTLSVerify: true,
@@ -174,6 +179,40 @@ func TestProxyHandler(t *testing.T) {
 			},
 			expectedStatusCode: http.StatusOK,
 			expectedCalled:     true,
+			expectedHeaders: map[string][]string{
+				"X-Forwarded-Proto": {"https"},
+				"X-Forwarded-Uri":   {"/request/path"},
+				"X-Forwarded-For":   {"127.0.0.1"},
+				"X-Remote-User":     {"username"},
+				"User-Agent":        {"Go-http-client/1.1"},
+				"Accept-Encoding":   {"gzip"},
+				"X-Remote-Group":    {"one", "two"},
+			},
+		},
+		"[RemoteRequestHeaderUID] proxy with user, insecure": {
+			user: &user.DefaultInfo{
+				Name:   "username",
+				UID:    "6b60d791-1af9-4513-92e5-e4252a1e0a78",
+				Groups: []string{"one", "two"},
+			},
+			path: "/request/path",
+			apiService: &apiregistration.APIService{
+				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
+				Spec: apiregistration.APIServiceSpec{
+					Service:               &apiregistration.ServiceReference{Port: ptr.To[int32](443)},
+					Group:                 "foo",
+					Version:               "v1",
+					InsecureSkipTLSVerify: true,
+				},
+				Status: apiregistration.APIServiceStatus{
+					Conditions: []apiregistration.APIServiceCondition{
+						{Type: apiregistration.Available, Status: apiregistration.ConditionTrue},
+					},
+				},
+			},
+			enableFeatureGates: []featuregate.Feature{features.RemoteRequestHeaderUID},
+			expectedStatusCode: http.StatusOK,
+			expectedCalled:     true,
 			expectedHeaders: map[string][]string{
 				"X-Forwarded-Proto": {"https"},
 				"X-Forwarded-Uri":   {"/request/path"},
@@ -195,7 +234,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 					Group:    "foo",
 					Version:  "v1",
 					CABundle: testCACrt,
@@ -208,6 +247,40 @@ func TestProxyHandler(t *testing.T) {
 			},
 			expectedStatusCode: http.StatusOK,
 			expectedCalled:     true,
+			expectedHeaders: map[string][]string{
+				"X-Forwarded-Proto": {"https"},
+				"X-Forwarded-Uri":   {"/request/path"},
+				"X-Forwarded-For":   {"127.0.0.1"},
+				"X-Remote-User":     {"username"},
+				"User-Agent":        {"Go-http-client/1.1"},
+				"Accept-Encoding":   {"gzip"},
+				"X-Remote-Group":    {"one", "two"},
+			},
+		},
+		"[RemoteRequestHeaderUID] proxy with user, cabundle": {
+			user: &user.DefaultInfo{
+				Name:   "username",
+				UID:    "6b60d791-1af9-4513-92e5-e4252a1e0a78",
+				Groups: []string{"one", "two"},
+			},
+			path: "/request/path",
+			apiService: &apiregistration.APIService{
+				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
+				Spec: apiregistration.APIServiceSpec{
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
+					Group:    "foo",
+					Version:  "v1",
+					CABundle: testCACrt,
+				},
+				Status: apiregistration.APIServiceStatus{
+					Conditions: []apiregistration.APIServiceCondition{
+						{Type: apiregistration.Available, Status: apiregistration.ConditionTrue},
+					},
+				},
+			},
+			enableFeatureGates: []featuregate.Feature{features.RemoteRequestHeaderUID},
+			expectedStatusCode: http.StatusOK,
+			expectedCalled:     true,
 			expectedHeaders: map[string][]string{
 				"X-Forwarded-Proto": {"https"},
 				"X-Forwarded-Uri":   {"/request/path"},
@@ -229,7 +302,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 					Group:    "foo",
 					Version:  "v1",
 					CABundle: testCACrt,
@@ -253,7 +326,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service:  &apiregistration.ServiceReference{Name: "bad-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "bad-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 					Group:    "foo",
 					Version:  "v1",
 					CABundle: testCACrt,
@@ -276,7 +349,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service: &apiregistration.ServiceReference{Port: pointer.Int32Ptr(443)},
+					Service: &apiregistration.ServiceReference{Port: ptr.To[int32](443)},
 					Group:   "foo",
 					Version: "v1",
 				},
@@ -298,7 +371,7 @@ func TestProxyHandler(t *testing.T) {
 			apiService: &apiregistration.APIService{
 				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 				Spec: apiregistration.APIServiceSpec{
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 					Group:    "foo",
 					Version:  "v1",
 					CABundle: testCACrt,
@@ -320,7 +393,11 @@ func TestProxyHandler(t *testing.T) {
 		target.Reset()
 		legacyregistry.Reset()
 
-		func() {
+		t.Run(name, func(t *testing.T) {
+			for _, f := range tc.enableFeatureGates {
+				featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, f, true)
+			}
+
 			targetServer := httptest.NewUnstartedServer(target)
 			serviceCert := tc.serviceCertOverride
 			if serviceCert == nil {
@@ -354,37 +431,37 @@ func TestProxyHandler(t *testing.T) {
 
 			resp, err := http.Get(server.URL + tc.path)
 			if err != nil {
-				t.Errorf("%s: %v", name, err)
+				t.Errorf("%v", err)
 				return
 			}
 			if e, a := tc.expectedStatusCode, resp.StatusCode; e != a {
 				body, _ := httputil.DumpResponse(resp, true)
-				t.Logf("%s: %v", name, string(body))
+				t.Logf("%v", string(body))
-				t.Errorf("%s: expected %v, got %v", name, e, a)
+				t.Errorf("expected %v, got %v", e, a)
 				return
 			}
 			bytes, err := io.ReadAll(resp.Body)
 			if err != nil {
-				t.Errorf("%s: %v", name, err)
+				t.Errorf("%v", err)
 				return
 			}
 			if !strings.Contains(string(bytes), tc.expectedBody) {
-				t.Errorf("%s: expected %q, got %q", name, tc.expectedBody, string(bytes))
+				t.Errorf("expected %q, got %q", tc.expectedBody, string(bytes))
 				return
 			}
 
 			if e, a := tc.expectedCalled, target.called; e != a {
-				t.Errorf("%s: expected %v, got %v", name, e, a)
+				t.Errorf("expected %v, got %v", e, a)
 				return
 			}
 			// this varies every test
 			delete(target.headers, "X-Forwarded-Host")
 			if e, a := tc.expectedHeaders, target.headers; !reflect.DeepEqual(e, a) {
-				t.Errorf("%s: expected %v, got %v", name, e, a)
+				t.Errorf("expected != got %v", cmp.Diff(e, a))
 				return
 			}
 			if e, a := targetServer.Listener.Addr().String(), target.host; tc.expectedCalled && !reflect.DeepEqual(e, a) {
-				t.Errorf("%s: expected %v, got %v", name, e, a)
+				t.Errorf("expected %v, got %v", e, a)
 				return
 			}
 
@@ -397,7 +474,7 @@ func TestProxyHandler(t *testing.T) {
 					t.Errorf("expected the x509_missing_san_total to be 1, but it's %d", errorCounter)
 				}
 			}
-		}()
+		})
 	}
 }
 
@@ -432,6 +509,8 @@ func newBrokenDialerAndSelector() (*mockEgressDialer, *egressselector.EgressSele
 }
 
 func TestProxyUpgrade(t *testing.T) {
+	featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.RemoteRequestHeaderUID, true)
+
 	upgradeUser := "upgradeUser"
 	upgradeUID := "upgradeUser-UID"
 	testcases := map[string]struct {
@@ -446,7 +525,7 @@ func TestProxyUpgrade(t *testing.T) {
 					CABundle: testCACrt,
 					Group:    "mygroup",
 					Version:  "v1",
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 				},
 				Status: apiregistration.APIServiceStatus{
 					Conditions: []apiregistration.APIServiceCondition{
@@ -463,7 +542,7 @@ func TestProxyUpgrade(t *testing.T) {
 					InsecureSkipTLSVerify: true,
 					Group:                 "mygroup",
 					Version:               "v1",
-					Service:               &apiregistration.ServiceReference{Name: "invalid-service", Namespace: "invalid-ns", Port: pointer.Int32Ptr(443)},
+					Service:               &apiregistration.ServiceReference{Name: "invalid-service", Namespace: "invalid-ns", Port: ptr.To[int32](443)},
 				},
 				Status: apiregistration.APIServiceStatus{
 					Conditions: []apiregistration.APIServiceCondition{
@@ -480,7 +559,7 @@ func TestProxyUpgrade(t *testing.T) {
 					CABundle: testCACrt,
 					Group:    "mygroup",
 					Version:  "v1",
-					Service:  &apiregistration.ServiceReference{Name: "invalid-service", Namespace: "invalid-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "invalid-service", Namespace: "invalid-ns", Port: ptr.To[int32](443)},
 				},
 				Status: apiregistration.APIServiceStatus{
 					Conditions: []apiregistration.APIServiceCondition{
@@ -497,7 +576,7 @@ func TestProxyUpgrade(t *testing.T) {
 					CABundle: testCACrt,
 					Group:    "mygroup",
 					Version:  "v1",
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 				},
 				Status: apiregistration.APIServiceStatus{
 					Conditions: []apiregistration.APIServiceCondition{
@@ -515,7 +594,7 @@ func TestProxyUpgrade(t *testing.T) {
 					CABundle: testCACrt,
 					Group:    "mygroup",
 					Version:  "v1",
-					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+					Service:  &apiregistration.ServiceReference{Name: "test-service", Namespace: "test-ns", Port: ptr.To[int32](443)},
 				},
 				Status: apiregistration.APIServiceStatus{
 					Conditions: []apiregistration.APIServiceCondition{
@@ -996,7 +1075,7 @@ func TestProxyCertReload(t *testing.T) {
 	apiService := &apiregistration.APIService{
 		ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
 		Spec: apiregistration.APIServiceSpec{
-			Service:  &apiregistration.ServiceReference{Name: "test-service2", Namespace: "test-ns", Port: pointer.Int32Ptr(443)},
+			Service:  &apiregistration.ServiceReference{Name: "test-service2", Namespace: "test-ns", Port: ptr.To[int32](443)},
 			Group:    "foo",
 			Version:  "v1",
 			CABundle: backendCaCertificate(), // used to validate backendCertificate()

staging/src/k8s.io/sample-apiserver/main.go

@@ -27,7 +27,7 @@ import (
 func main() {
 	ctx := genericapiserver.SetupSignalContext()
 	options := server.NewWardleServerOptions(os.Stdout, os.Stderr)
-	cmd := server.NewCommandStartWardleServer(ctx, options)
+	cmd := server.NewCommandStartWardleServer(ctx, options, false)
 	code := cli.Run(cmd)
 	os.Exit(code)
 }

staging/src/k8s.io/sample-apiserver/pkg/cmd/server/start.go

@@ -90,12 +90,15 @@ func NewWardleServerOptions(out, errOut io.Writer) *WardleServerOptions {
 
 // NewCommandStartWardleServer provides a CLI handler for 'start master' command
 // with a default WardleServerOptions.
-func NewCommandStartWardleServer(ctx context.Context, defaults *WardleServerOptions) *cobra.Command {
+func NewCommandStartWardleServer(ctx context.Context, defaults *WardleServerOptions, skipDefaultComponentGlobalsRegistrySet bool) *cobra.Command {
 	o := *defaults
 	cmd := &cobra.Command{
 		Short: "Launch a wardle API server",
 		Long:  "Launch a wardle API server",
 		PersistentPreRunE: func(*cobra.Command, []string) error {
+			if skipDefaultComponentGlobalsRegistrySet {
+				return nil
+			}
 			return featuregate.DefaultComponentGlobalsRegistry.Set()
 		},
 		RunE: func(c *cobra.Command, args []string) error {

test/featuregates_linter/test_data/versioned_feature_list.yaml

@@ -1058,6 +1058,12 @@
     lockToDefault: true
     preRelease: GA
     version: "1.29"
+- name: RemoteRequestHeaderUID
+  versionedSpecs:
+  - default: false
+    lockToDefault: false
+    preRelease: Alpha
+    version: "1.32"
 - name: ResilientWatchCacheInitialization
   versionedSpecs:
   - default: true

test/integration/auth/requestheader_test.go

@@ -27,11 +27,14 @@ import (
 
 	authnv1 "k8s.io/api/authentication/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apiserver/pkg/features"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	certutil "k8s.io/client-go/util/cert"
 	"k8s.io/client-go/util/keyutil"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 	"k8s.io/kubernetes/cmd/kube-apiserver/app/options"
 	"k8s.io/kubernetes/test/integration/framework"
 	testutils "k8s.io/kubernetes/test/utils"
@@ -39,6 +42,8 @@ import (
 )
 
 func TestAuthnToKAS(t *testing.T) {
+	featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.RemoteRequestHeaderUID, true)
+
 	tCtx := ktesting.Init(t)
 
 	frontProxyCA, frontProxyClient, frontProxyKey, err := newTestCAWithClient(

test/integration/examples/apiserver_test.go

@@ -45,8 +45,10 @@ import (
 	"k8s.io/apiserver/pkg/authentication/serviceaccount"
 	"k8s.io/apiserver/pkg/authentication/user"
 	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/features"
 	"k8s.io/apiserver/pkg/server/dynamiccertificates"
 	genericapiserveroptions "k8s.io/apiserver/pkg/server/options"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	client "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -54,6 +56,7 @@ import (
 	"k8s.io/client-go/transport"
 	"k8s.io/client-go/util/cert"
 	"k8s.io/component-base/featuregate"
+	featuregatetesting "k8s.io/component-base/featuregate/testing"
 	utilversion "k8s.io/component-base/version"
 	apiregistrationv1 "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1"
 	aggregatorclient "k8s.io/kube-aggregator/pkg/client/clientset_generated/clientset"
@@ -260,6 +263,7 @@ func TestFrontProxyConfig(t *testing.T) {
 		testFrontProxyConfig(t, false)
 	})
 	t.Run("WithUID", func(t *testing.T) {
+		featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.RemoteRequestHeaderUID, true)
 		testFrontProxyConfig(t, true)
 	})
 }
@@ -282,7 +286,7 @@ func testFrontProxyConfig(t *testing.T, withUID bool) {
 	kubeBinaryVersion := sampleserver.WardleVersionToKubeVersion(version.MustParse(wardleBinaryVersion)).String()
 
 	// start up the KAS and prepare the options for the wardle API server
-	testKAS, wardleOptions, wardlePort := prepareAggregatedWardleAPIServer(ctx, t, testNamespace, kubeBinaryVersion, wardleBinaryVersion, extraKASFlags)
+	testKAS, wardleOptions, wardlePort := prepareAggregatedWardleAPIServer(ctx, t, testNamespace, kubeBinaryVersion, wardleBinaryVersion, extraKASFlags, withUID)
 	kubeConfig := getKubeConfig(testKAS)
 
 	// create the SA that we will use to query the aggregated API
@@ -337,12 +341,12 @@ func testFrontProxyConfig(t *testing.T, withUID bool) {
 		transport.WrapperFunc(func(rt http.RoundTripper) http.RoundTripper {
 			return roundTripperFunc(func(req *http.Request) (*http.Response, error) {
 				gotUser, ok := genericapirequest.UserFrom(req.Context())
-				if !ok || gotUser.GetName() == "system:anonymous" {
+				if !ok {
 					return nil, fmt.Errorf("got an unauthenticated request")
 				}
 
 				// this is likely the KAS checking the OpenAPI endpoints
-				if gotUser.GetName() == "system:anonymous" || gotUser.GetName() == "system:aggregator" {
+				if gotUser.GetName() == "system:anonymous" || gotUser.GetName() == "system:aggregator" || gotUser.GetName() == "system:kube-aggregator" {
 					return rt.RoundTrip(req)
 				}
 
@@ -368,7 +372,7 @@ func testFrontProxyConfig(t *testing.T, withUID bool) {
 	wardleCertDir, _ := os.MkdirTemp("", "test-integration-wardle-server")
 	defer os.RemoveAll(wardleCertDir)
 
-	runPreparedWardleServer(ctx, t, wardleOptions, wardleCertDir, wardlePort, false, true, wardleBinaryVersion, kubeConfig)
+	runPreparedWardleServer(ctx, t, wardleOptions, wardleCertDir, wardlePort, false, true, wardleBinaryVersion, kubeConfig, withUID)
 	waitForWardleAPIServiceReady(ctx, t, kubeConfig, wardleCertDir, testNamespace)
 
 	// get the wardle API client using our SA token
@@ -401,13 +405,13 @@ func testAggregatedAPIServer(t *testing.T, setWardleFeatureGate, banFlunder bool
 	// each wardle binary is bundled with a specific kube binary.
 	kubeBinaryVersion := sampleserver.WardleVersionToKubeVersion(version.MustParse(wardleBinaryVersion)).String()
 
-	testKAS, wardleOptions, wardlePort := prepareAggregatedWardleAPIServer(ctx, t, testNamespace, kubeBinaryVersion, wardleBinaryVersion, nil)
+	testKAS, wardleOptions, wardlePort := prepareAggregatedWardleAPIServer(ctx, t, testNamespace, kubeBinaryVersion, wardleBinaryVersion, nil, false)
 	kubeClientConfig := getKubeConfig(testKAS)
 
 	wardleCertDir, _ := os.MkdirTemp("", "test-integration-wardle-server")
 	defer os.RemoveAll(wardleCertDir)
 
-	directWardleClientConfig := runPreparedWardleServer(ctx, t, wardleOptions, wardleCertDir, wardlePort, setWardleFeatureGate, banFlunder, wardleEmulationVersion, kubeClientConfig)
+	directWardleClientConfig := runPreparedWardleServer(ctx, t, wardleOptions, wardleCertDir, wardlePort, setWardleFeatureGate, banFlunder, wardleEmulationVersion, kubeClientConfig, false)
 
 	// now we're finally ready to test. These are what's run by default now
 	wardleDirectClient := client.NewForConfigOrDie(directWardleClientConfig)
@@ -681,7 +685,7 @@ func TestAggregatedAPIServerRejectRedirectResponse(t *testing.T) {
 	}
 }
 
-func prepareAggregatedWardleAPIServer(ctx context.Context, t *testing.T, namespace, kubebinaryVersion, wardleBinaryVersion string, kubeAPIServerFlags []string) (*kastesting.TestServer, *sampleserver.WardleServerOptions, int) {
+func prepareAggregatedWardleAPIServer(ctx context.Context, t *testing.T, namespace, kubebinaryVersion, wardleBinaryVersion string, kubeAPIServerFlags []string, withUID bool) (*kastesting.TestServer, *sampleserver.WardleServerOptions, int) {
 	// makes the kube-apiserver very responsive.  it's normally a minute
 	dynamiccertificates.FileRefreshDuration = 1 * time.Second
 
@@ -693,6 +697,11 @@ func prepareAggregatedWardleAPIServer(ctx context.Context, t *testing.T, namespa
 	// endpoints cannot have loopback IPs so we need to override the resolver itself
 	t.Cleanup(app.SetServiceResolverForTests(staticURLServiceResolver(fmt.Sprintf("https://127.0.0.1:%d", wardlePort))))
 
+	// TODO figure out how to actually make BinaryVersion/EmulationVersion work with Wardle and KAS at the same time when Alpha FG are being set
+	if withUID {
+		kubebinaryVersion = ""
+	}
+
 	testServer := kastesting.StartTestServerOrDie(t,
 		&kastesting.TestServerInstanceOptions{
 			EnableCertAuth: true,
@@ -751,6 +760,7 @@ func runPreparedWardleServer(
 	banFlunder bool,
 	emulationVersion string,
 	kubeConfig *rest.Config,
+	withUID bool,
 ) *rest.Config {
 
 	// start the wardle server to prove we can aggregate it
@@ -769,7 +779,8 @@ func runPreparedWardleServer(
 		if flunderBanningFeatureGate {
 			args = append(args, "--feature-gates", fmt.Sprintf("wardle:BanFlunder=%v", banFlunder))
 		}
-		wardleCmd := sampleserver.NewCommandStartWardleServer(ctx, wardleOptions)
+		// TODO figure out how to actually make BinaryVersion/EmulationVersion work with Wardle and KAS at the same time when Alpha FG are being set
+		wardleCmd := sampleserver.NewCommandStartWardleServer(ctx, wardleOptions, withUID)
 		wardleCmd.SetArgs(args)
 		if err := wardleCmd.Execute(); err != nil {
 			t.Error(err)