KEP-4633: Allow health-only anonymous auth mode.

Signed-off-by: Vinayak Goyal <vinaygo@google.com>

Kubernetes-commit: 5e6a4937f5a3e20dd77238946220461332ecddff

pkg/apis/apiserver/types.go

@@ -165,6 +165,25 @@ type AuthenticationConfiguration struct {
 	metav1.TypeMeta
 
 	JWT []JWTAuthenticator
+
+	// If present --anonymous-auth must not be set
+	Anonymous *AnonymousAuthConfig
+}
+
+// AnonymousAuthConfig provides the configuration for the anonymous authenticator.
+type AnonymousAuthConfig struct {
+	Enabled bool
+
+	// If set, anonymous auth is only allowed if the request meets one of the
+	// conditions.
+	Conditions []AnonymousAuthCondition
+}
+
+// AnonymousAuthCondition describes the condition under which anonymous auth
+// should be enabled.
+type AnonymousAuthCondition struct {
+	// Path for which anonymous auth is enabled.
+	Path string
 }
 
 // JWTAuthenticator provides the configuration for a single JWT authenticator.

pkg/apis/apiserver/v1alpha1/types.go

@@ -185,6 +185,25 @@ type AuthenticationConfiguration struct {
 	//		"<username claim>": "username"
 	// }
 	JWT []JWTAuthenticator `json:"jwt"`
+
+	// If present --anonymous-auth must not be set
+	Anonymous *AnonymousAuthConfig `json:"anonymous,omitempty"`
+}
+
+// AnonymousAuthConfig provides the configuration for the anonymous authenticator.
+type AnonymousAuthConfig struct {
+	Enabled bool `json:"enabled"`
+
+	// If set, anonymous auth is only allowed if the request meets one of the
+	// conditions.
+	Conditions []AnonymousAuthCondition `json:"conditions,omitempty"`
+}
+
+// AnonymousAuthCondition describes the condition under which anonymous auth
+// should be enabled.
+type AnonymousAuthCondition struct {
+	// Path for which anonymous auth is enabled.
+	Path string `json:"path"`
 }
 
 // JWTAuthenticator provides the configuration for a single JWT authenticator.

pkg/apis/apiserver/v1alpha1/zz_generated.conversion.go

@@ -57,6 +57,26 @@ func RegisterConversions(s *runtime.Scheme) error {
 	}); err != nil {
 		return err
 	}
+	if err := s.AddGeneratedConversionFunc((*AnonymousAuthCondition)(nil), (*apiserver.AnonymousAuthCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(a.(*AnonymousAuthCondition), b.(*apiserver.AnonymousAuthCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserver.AnonymousAuthCondition)(nil), (*AnonymousAuthCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserver_AnonymousAuthCondition_To_v1alpha1_AnonymousAuthCondition(a.(*apiserver.AnonymousAuthCondition), b.(*AnonymousAuthCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*AnonymousAuthConfig)(nil), (*apiserver.AnonymousAuthConfig)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1alpha1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(a.(*AnonymousAuthConfig), b.(*apiserver.AnonymousAuthConfig), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserver.AnonymousAuthConfig)(nil), (*AnonymousAuthConfig)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserver_AnonymousAuthConfig_To_v1alpha1_AnonymousAuthConfig(a.(*apiserver.AnonymousAuthConfig), b.(*AnonymousAuthConfig), scope)
+	}); err != nil {
+		return err
+	}
 	if err := s.AddGeneratedConversionFunc((*AuthenticationConfiguration)(nil), (*apiserver.AuthenticationConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_v1alpha1_AuthenticationConfiguration_To_apiserver_AuthenticationConfiguration(a.(*AuthenticationConfiguration), b.(*apiserver.AuthenticationConfiguration), scope)
 	}); err != nil {
@@ -324,6 +344,48 @@ func Convert_apiserver_AdmissionPluginConfiguration_To_v1alpha1_AdmissionPluginC
 	return autoConvert_apiserver_AdmissionPluginConfiguration_To_v1alpha1_AdmissionPluginConfiguration(in, out, s)
 }
 
+func autoConvert_v1alpha1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in *AnonymousAuthCondition, out *apiserver.AnonymousAuthCondition, s conversion.Scope) error {
+	out.Path = in.Path
+	return nil
+}
+
+// Convert_v1alpha1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition is an autogenerated conversion function.
+func Convert_v1alpha1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in *AnonymousAuthCondition, out *apiserver.AnonymousAuthCondition, s conversion.Scope) error {
+	return autoConvert_v1alpha1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in, out, s)
+}
+
+func autoConvert_apiserver_AnonymousAuthCondition_To_v1alpha1_AnonymousAuthCondition(in *apiserver.AnonymousAuthCondition, out *AnonymousAuthCondition, s conversion.Scope) error {
+	out.Path = in.Path
+	return nil
+}
+
+// Convert_apiserver_AnonymousAuthCondition_To_v1alpha1_AnonymousAuthCondition is an autogenerated conversion function.
+func Convert_apiserver_AnonymousAuthCondition_To_v1alpha1_AnonymousAuthCondition(in *apiserver.AnonymousAuthCondition, out *AnonymousAuthCondition, s conversion.Scope) error {
+	return autoConvert_apiserver_AnonymousAuthCondition_To_v1alpha1_AnonymousAuthCondition(in, out, s)
+}
+
+func autoConvert_v1alpha1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in *AnonymousAuthConfig, out *apiserver.AnonymousAuthConfig, s conversion.Scope) error {
+	out.Enabled = in.Enabled
+	out.Conditions = *(*[]apiserver.AnonymousAuthCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_v1alpha1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig is an autogenerated conversion function.
+func Convert_v1alpha1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in *AnonymousAuthConfig, out *apiserver.AnonymousAuthConfig, s conversion.Scope) error {
+	return autoConvert_v1alpha1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in, out, s)
+}
+
+func autoConvert_apiserver_AnonymousAuthConfig_To_v1alpha1_AnonymousAuthConfig(in *apiserver.AnonymousAuthConfig, out *AnonymousAuthConfig, s conversion.Scope) error {
+	out.Enabled = in.Enabled
+	out.Conditions = *(*[]AnonymousAuthCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_apiserver_AnonymousAuthConfig_To_v1alpha1_AnonymousAuthConfig is an autogenerated conversion function.
+func Convert_apiserver_AnonymousAuthConfig_To_v1alpha1_AnonymousAuthConfig(in *apiserver.AnonymousAuthConfig, out *AnonymousAuthConfig, s conversion.Scope) error {
+	return autoConvert_apiserver_AnonymousAuthConfig_To_v1alpha1_AnonymousAuthConfig(in, out, s)
+}
+
 func autoConvert_v1alpha1_AuthenticationConfiguration_To_apiserver_AuthenticationConfiguration(in *AuthenticationConfiguration, out *apiserver.AuthenticationConfiguration, s conversion.Scope) error {
 	if in.JWT != nil {
 		in, out := &in.JWT, &out.JWT
@@ -336,6 +398,7 @@ func autoConvert_v1alpha1_AuthenticationConfiguration_To_apiserver_Authenticatio
 	} else {
 		out.JWT = nil
 	}
+	out.Anonymous = (*apiserver.AnonymousAuthConfig)(unsafe.Pointer(in.Anonymous))
 	return nil
 }
 
@@ -356,6 +419,7 @@ func autoConvert_apiserver_AuthenticationConfiguration_To_v1alpha1_Authenticatio
 	} else {
 		out.JWT = nil
 	}
+	out.Anonymous = (*AnonymousAuthConfig)(unsafe.Pointer(in.Anonymous))
 	return nil
 }
 

pkg/apis/apiserver/v1alpha1/zz_generated.deepcopy.go

@@ -78,6 +78,43 @@ func (in *AdmissionPluginConfiguration) DeepCopy() *AdmissionPluginConfiguration
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthCondition) DeepCopyInto(out *AnonymousAuthCondition) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthCondition.
+func (in *AnonymousAuthCondition) DeepCopy() *AnonymousAuthCondition {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthCondition)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthConfig) DeepCopyInto(out *AnonymousAuthConfig) {
+	*out = *in
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]AnonymousAuthCondition, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthConfig.
+func (in *AnonymousAuthConfig) DeepCopy() *AnonymousAuthConfig {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthConfig)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfiguration) {
 	*out = *in
@@ -89,6 +126,11 @@ func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfigura
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	if in.Anonymous != nil {
+		in, out := &in.Anonymous, &out.Anonymous
+		*out = new(AnonymousAuthConfig)
+		(*in).DeepCopyInto(*out)
+	}
 	return
 }
 

pkg/apis/apiserver/v1beta1/types.go

@@ -156,6 +156,25 @@ type AuthenticationConfiguration struct {
 	//		"<username claim>": "username"
 	// }
 	JWT []JWTAuthenticator `json:"jwt"`
+
+	// If present --anonymous-auth must not be set
+	Anonymous *AnonymousAuthConfig `json:"anonymous,omitempty"`
+}
+
+// AnonymousAuthConfig provides the configuration for the anonymous authenticator.
+type AnonymousAuthConfig struct {
+	Enabled bool `json:"enabled"`
+
+	// If set, anonymous auth is only allowed if the request meets one of the
+	// conditions.
+	Conditions []AnonymousAuthCondition `json:"conditions,omitempty"`
+}
+
+// AnonymousAuthCondition describes the condition under which anonymous auth
+// should be enabled.
+type AnonymousAuthCondition struct {
+	// Path for which anonymous auth is enabled.
+	Path string `json:"path"`
 }
 
 // JWTAuthenticator provides the configuration for a single JWT authenticator.

pkg/apis/apiserver/v1beta1/zz_generated.conversion.go

@@ -37,6 +37,26 @@ func init() {
 // RegisterConversions adds conversion functions to the given scheme.
 // Public to allow building arbitrary schemes.
 func RegisterConversions(s *runtime.Scheme) error {
+	if err := s.AddGeneratedConversionFunc((*AnonymousAuthCondition)(nil), (*apiserver.AnonymousAuthCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1beta1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(a.(*AnonymousAuthCondition), b.(*apiserver.AnonymousAuthCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserver.AnonymousAuthCondition)(nil), (*AnonymousAuthCondition)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserver_AnonymousAuthCondition_To_v1beta1_AnonymousAuthCondition(a.(*apiserver.AnonymousAuthCondition), b.(*AnonymousAuthCondition), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*AnonymousAuthConfig)(nil), (*apiserver.AnonymousAuthConfig)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_v1beta1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(a.(*AnonymousAuthConfig), b.(*apiserver.AnonymousAuthConfig), scope)
+	}); err != nil {
+		return err
+	}
+	if err := s.AddGeneratedConversionFunc((*apiserver.AnonymousAuthConfig)(nil), (*AnonymousAuthConfig)(nil), func(a, b interface{}, scope conversion.Scope) error {
+		return Convert_apiserver_AnonymousAuthConfig_To_v1beta1_AnonymousAuthConfig(a.(*apiserver.AnonymousAuthConfig), b.(*AnonymousAuthConfig), scope)
+	}); err != nil {
+		return err
+	}
 	if err := s.AddGeneratedConversionFunc((*AuthenticationConfiguration)(nil), (*apiserver.AuthenticationConfiguration)(nil), func(a, b interface{}, scope conversion.Scope) error {
 		return Convert_v1beta1_AuthenticationConfiguration_To_apiserver_AuthenticationConfiguration(a.(*AuthenticationConfiguration), b.(*apiserver.AuthenticationConfiguration), scope)
 	}); err != nil {
@@ -260,6 +280,48 @@ func RegisterConversions(s *runtime.Scheme) error {
 	return nil
 }
 
+func autoConvert_v1beta1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in *AnonymousAuthCondition, out *apiserver.AnonymousAuthCondition, s conversion.Scope) error {
+	out.Path = in.Path
+	return nil
+}
+
+// Convert_v1beta1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition is an autogenerated conversion function.
+func Convert_v1beta1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in *AnonymousAuthCondition, out *apiserver.AnonymousAuthCondition, s conversion.Scope) error {
+	return autoConvert_v1beta1_AnonymousAuthCondition_To_apiserver_AnonymousAuthCondition(in, out, s)
+}
+
+func autoConvert_apiserver_AnonymousAuthCondition_To_v1beta1_AnonymousAuthCondition(in *apiserver.AnonymousAuthCondition, out *AnonymousAuthCondition, s conversion.Scope) error {
+	out.Path = in.Path
+	return nil
+}
+
+// Convert_apiserver_AnonymousAuthCondition_To_v1beta1_AnonymousAuthCondition is an autogenerated conversion function.
+func Convert_apiserver_AnonymousAuthCondition_To_v1beta1_AnonymousAuthCondition(in *apiserver.AnonymousAuthCondition, out *AnonymousAuthCondition, s conversion.Scope) error {
+	return autoConvert_apiserver_AnonymousAuthCondition_To_v1beta1_AnonymousAuthCondition(in, out, s)
+}
+
+func autoConvert_v1beta1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in *AnonymousAuthConfig, out *apiserver.AnonymousAuthConfig, s conversion.Scope) error {
+	out.Enabled = in.Enabled
+	out.Conditions = *(*[]apiserver.AnonymousAuthCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_v1beta1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig is an autogenerated conversion function.
+func Convert_v1beta1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in *AnonymousAuthConfig, out *apiserver.AnonymousAuthConfig, s conversion.Scope) error {
+	return autoConvert_v1beta1_AnonymousAuthConfig_To_apiserver_AnonymousAuthConfig(in, out, s)
+}
+
+func autoConvert_apiserver_AnonymousAuthConfig_To_v1beta1_AnonymousAuthConfig(in *apiserver.AnonymousAuthConfig, out *AnonymousAuthConfig, s conversion.Scope) error {
+	out.Enabled = in.Enabled
+	out.Conditions = *(*[]AnonymousAuthCondition)(unsafe.Pointer(&in.Conditions))
+	return nil
+}
+
+// Convert_apiserver_AnonymousAuthConfig_To_v1beta1_AnonymousAuthConfig is an autogenerated conversion function.
+func Convert_apiserver_AnonymousAuthConfig_To_v1beta1_AnonymousAuthConfig(in *apiserver.AnonymousAuthConfig, out *AnonymousAuthConfig, s conversion.Scope) error {
+	return autoConvert_apiserver_AnonymousAuthConfig_To_v1beta1_AnonymousAuthConfig(in, out, s)
+}
+
 func autoConvert_v1beta1_AuthenticationConfiguration_To_apiserver_AuthenticationConfiguration(in *AuthenticationConfiguration, out *apiserver.AuthenticationConfiguration, s conversion.Scope) error {
 	if in.JWT != nil {
 		in, out := &in.JWT, &out.JWT
@@ -272,6 +334,7 @@ func autoConvert_v1beta1_AuthenticationConfiguration_To_apiserver_Authentication
 	} else {
 		out.JWT = nil
 	}
+	out.Anonymous = (*apiserver.AnonymousAuthConfig)(unsafe.Pointer(in.Anonymous))
 	return nil
 }
 
@@ -292,6 +355,7 @@ func autoConvert_apiserver_AuthenticationConfiguration_To_v1beta1_Authentication
 	} else {
 		out.JWT = nil
 	}
+	out.Anonymous = (*AnonymousAuthConfig)(unsafe.Pointer(in.Anonymous))
 	return nil
 }
 

pkg/apis/apiserver/v1beta1/zz_generated.deepcopy.go

@@ -25,6 +25,43 @@ import (
 	runtime "k8s.io/apimachinery/pkg/runtime"
 )
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthCondition) DeepCopyInto(out *AnonymousAuthCondition) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthCondition.
+func (in *AnonymousAuthCondition) DeepCopy() *AnonymousAuthCondition {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthCondition)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthConfig) DeepCopyInto(out *AnonymousAuthConfig) {
+	*out = *in
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]AnonymousAuthCondition, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthConfig.
+func (in *AnonymousAuthConfig) DeepCopy() *AnonymousAuthConfig {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthConfig)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfiguration) {
 	*out = *in
@@ -36,6 +73,11 @@ func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfigura
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	if in.Anonymous != nil {
+		in, out := &in.Anonymous, &out.Anonymous
+		*out = new(AnonymousAuthConfig)
+		(*in).DeepCopyInto(*out)
+	}
 	return
 }
 

pkg/apis/apiserver/validation/validation.go

@@ -78,6 +78,15 @@ func ValidateAuthenticationConfiguration(c *api.AuthenticationConfiguration, dis
 		}
 	}
 
+	if c.Anonymous != nil {
+		if !utilfeature.DefaultFeatureGate.Enabled(features.AnonymousAuthConfigurableEndpoints) {
+			allErrs = append(allErrs, field.Forbidden(field.NewPath("anonymous"), "anonymous is not supported when when AnonymousAuthConfigurableEnpoints feature gate is disabled"))
+		}
+		if !c.Anonymous.Enabled && len(c.Anonymous.Conditions) > 0 {
+			allErrs = append(allErrs, field.Invalid(field.NewPath("anonymous", "conditions"), c.Anonymous.Conditions, "enabled should be set to true when conditions are defined"))
+		}
+	}
+
 	return allErrs
 }
 

pkg/apis/apiserver/zz_generated.deepcopy.go

@@ -100,6 +100,43 @@ func (in *AdmissionPluginConfiguration) DeepCopy() *AdmissionPluginConfiguration
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthCondition) DeepCopyInto(out *AnonymousAuthCondition) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthCondition.
+func (in *AnonymousAuthCondition) DeepCopy() *AnonymousAuthCondition {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthCondition)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *AnonymousAuthConfig) DeepCopyInto(out *AnonymousAuthConfig) {
+	*out = *in
+	if in.Conditions != nil {
+		in, out := &in.Conditions, &out.Conditions
+		*out = make([]AnonymousAuthCondition, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new AnonymousAuthConfig.
+func (in *AnonymousAuthConfig) DeepCopy() *AnonymousAuthConfig {
+	if in == nil {
+		return nil
+	}
+	out := new(AnonymousAuthConfig)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfiguration) {
 	*out = *in
@@ -111,6 +148,11 @@ func (in *AuthenticationConfiguration) DeepCopyInto(out *AuthenticationConfigura
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	if in.Anonymous != nil {
+		in, out := &in.Anonymous, &out.Anonymous
+		*out = new(AnonymousAuthConfig)
+		(*in).DeepCopyInto(*out)
+	}
 	return
 }
 

pkg/authentication/authenticatorfactory/delegating.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apiserver/pkg/apis/apiserver"
 	"k8s.io/apiserver/pkg/authentication/authenticator"
 	"k8s.io/apiserver/pkg/authentication/group"
 	"k8s.io/apiserver/pkg/authentication/request/anonymous"
@@ -39,7 +40,7 @@ import (
 // DelegatingAuthenticatorConfig is the minimal configuration needed to create an authenticator
 // built to delegate authentication to a kube API server
 type DelegatingAuthenticatorConfig struct {
-	Anonymous bool
+	Anonymous *apiserver.AnonymousAuthConfig
 
 	// TokenAccessReviewClient is a client to do token review. It can be nil. Then every token is ignored.
 	TokenAccessReviewClient authenticationclient.AuthenticationV1Interface
@@ -112,15 +113,15 @@ func (c DelegatingAuthenticatorConfig) New() (authenticator.Request, *spec.Secur
 	}
 
 	if len(authenticators) == 0 {
-		if c.Anonymous {
-			return anonymous.NewAuthenticator(), &securityDefinitions, nil
+		if c.Anonymous != nil && c.Anonymous.Enabled {
+			return anonymous.NewAuthenticator(c.Anonymous.Conditions), &securityDefinitions, nil
 		}
-		return nil, nil, errors.New("No authentication method configured")
+		return nil, nil, errors.New("no authentication method configured")
 	}
 
 	authenticator := group.NewAuthenticatedGroupAdder(unionauth.New(authenticators...))
-	if c.Anonymous {
-		authenticator = unionauth.NewFailOnError(authenticator, anonymous.NewAuthenticator())
+	if c.Anonymous != nil && c.Anonymous.Enabled {
+		authenticator = unionauth.NewFailOnError(authenticator, anonymous.NewAuthenticator(c.Anonymous.Conditions))
 	}
 	return authenticator, &securityDefinitions, nil
 }

pkg/authentication/request/anonymous/anonymous.go

@@ -19,25 +19,44 @@ package anonymous
 import (
 	"net/http"
 
+	"k8s.io/apiserver/pkg/apis/apiserver"
 	"k8s.io/apiserver/pkg/authentication/authenticator"
 	"k8s.io/apiserver/pkg/authentication/user"
 )
 
 const (
-	anonymousUser = user.Anonymous
-
+	anonymousUser        = user.Anonymous
 	unauthenticatedGroup = user.AllUnauthenticated
 )
 
-func NewAuthenticator() authenticator.Request {
-	return authenticator.RequestFunc(func(req *http.Request) (*authenticator.Response, bool, error) {
-		auds, _ := authenticator.AudiencesFrom(req.Context())
-		return &authenticator.Response{
-			User: &user.DefaultInfo{
-				Name:   anonymousUser,
-				Groups: []string{unauthenticatedGroup},
-			},
-			Audiences: auds,
-		}, true, nil
-	})
+type Authenticator struct {
+	allowedPaths map[string]bool
+}
+
+func (a *Authenticator) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	if len(a.allowedPaths) > 0 && !a.allowedPaths[req.URL.Path] {
+		return nil, false, nil
+	}
+
+	auds, _ := authenticator.AudiencesFrom(req.Context())
+	return &authenticator.Response{
+		User: &user.DefaultInfo{
+			Name:   anonymousUser,
+			Groups: []string{unauthenticatedGroup},
+		},
+		Audiences: auds,
+	}, true, nil
+}
+
+// NewAuthenticator returns a new anonymous authenticator.
+// When conditions is empty all requests are authenticated as anonymous.
+// When conditions are non-empty only those requests that match the at-least one
+// condition are authenticated as anonymous.
+func NewAuthenticator(conditions []apiserver.AnonymousAuthCondition) authenticator.Request {
+	allowedPaths := make(map[string]bool)
+	for _, c := range conditions {
+		allowedPaths[c.Path] = true
+	}
+
+	return &Authenticator{allowedPaths: allowedPaths}
 }

pkg/authentication/request/anonymous/anonymous_test.go

@@ -18,15 +18,16 @@ package anonymous
 
 import (
 	"net/http"
+	"net/url"
 	"testing"
 
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/apis/apiserver"
 	"k8s.io/apiserver/pkg/authentication/user"
 )
 
 func TestAnonymous(t *testing.T) {
-	var a authenticator.Request = NewAuthenticator()
+	a := NewAuthenticator(nil)
 	r, ok, err := a.AuthenticateRequest(&http.Request{})
 	if err != nil {
 		t.Fatalf("Unexpected error %v", err)
@@ -41,3 +42,85 @@ func TestAnonymous(t *testing.T) {
 		t.Fatalf("Expected group %s, got %v", user.AllUnauthenticated, r.User.GetGroups())
 	}
 }
+
+func TestAnonymousRestricted(t *testing.T) {
+	a := NewAuthenticator([]apiserver.AnonymousAuthCondition{
+		{
+			Path: "/healthz",
+		},
+		{
+			Path: "/readyz",
+		},
+		{
+			Path: "/livez",
+		},
+	})
+
+	testCases := []struct {
+		desc        string
+		path        string
+		want        user.DefaultInfo
+		wantAllowed bool
+	}{
+		{
+			desc: "/healthz",
+			path: "https://123.123.123.123/healthz",
+			want: user.DefaultInfo{
+				Name:   anonymousUser,
+				Groups: []string{unauthenticatedGroup},
+			},
+			wantAllowed: true,
+		},
+		{
+			desc: "/readyz",
+			path: "https://123.123.123.123/readyz",
+			want: user.DefaultInfo{
+				Name:   anonymousUser,
+				Groups: []string{unauthenticatedGroup},
+			},
+			wantAllowed: true,
+		},
+		{
+			desc: "/livez",
+			path: "https://123.123.123.123/livez",
+			want: user.DefaultInfo{
+				Name:   anonymousUser,
+				Groups: []string{unauthenticatedGroup},
+			},
+			wantAllowed: true,
+		},
+		{
+			desc:        "/api",
+			path:        "https://123.123.123.123/api",
+			wantAllowed: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			u, err := url.Parse(tc.path)
+			if err != nil {
+				t.Fatal(err)
+			}
+			r, allowed, err := a.AuthenticateRequest(&http.Request{URL: u})
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if tc.wantAllowed != allowed {
+				t.Fatalf("want allowed: %v, got allowed: %v", tc.wantAllowed, allowed)
+			}
+
+			if !tc.wantAllowed {
+				return
+			}
+
+			if r.User.GetName() != tc.want.Name {
+				t.Fatalf("Expected username %s, got %s", user.Anonymous, r.User.GetName())
+			}
+			if !sets.NewString(r.User.GetGroups()...).Equal(sets.NewString(tc.want.Groups...)) {
+				t.Fatalf("Expected group %s, got %v", tc.want.Groups, r.User.GetGroups())
+			}
+		})
+	}
+}

pkg/endpoints/filters/authentication_test.go

@@ -487,7 +487,7 @@ func TestUnauthenticatedHTTP2ClientConnectionClose(t *testing.T) {
 			case "error":
 				return nil, false, errors.New("authn err")
 			case "anonymous":
-				return anonymous.NewAuthenticator().AuthenticateRequest(r)
+				return anonymous.NewAuthenticator(nil).AuthenticateRequest(r)
 			case "anonymous_group":
 				return &authenticator.Response{User: &user.DefaultInfo{Groups: []string{user.AllUnauthenticated}}}, true, nil
 			default:

pkg/features/kube_features.go

@@ -53,6 +53,13 @@ const (
 	// caching with ETags containing all APIResources known to the apiserver.
 	AggregatedDiscoveryEndpoint featuregate.Feature = "AggregatedDiscoveryEndpoint"
 
+	// owner: @vinayakankugoyal
+	// kep: https://kep.k8s.io/4633
+	// alpha: v1.31
+	//
+	// Allows us to enable anonymous auth for only certain apiserver endpoints.
+	AnonymousAuthConfigurableEndpoints featuregate.Feature = "AnonymousAuthConfigurableEndpoints"
+
 	// owner: @smarterclayton
 	// alpha: v1.8
 	// beta: v1.9
@@ -340,6 +347,8 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 // available throughout Kubernetes binaries.
 var defaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureSpec{
 
+	AnonymousAuthConfigurableEndpoints: {Default: false, PreRelease: featuregate.Alpha},
+
 	AggregatedDiscoveryEndpoint: {Default: true, PreRelease: featuregate.GA, LockToDefault: true}, // remove in 1.33
 
 	AdmissionWebhookMatchConditions: {Default: true, PreRelease: featuregate.GA, LockToDefault: true}, // remove in 1.33

pkg/server/options/authentication.go

@@ -26,6 +26,7 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apiserver/pkg/apis/apiserver"
 	"k8s.io/apiserver/pkg/authentication/authenticatorfactory"
 	"k8s.io/apiserver/pkg/authentication/request/headerrequest"
 	"k8s.io/apiserver/pkg/server"
@@ -222,8 +223,8 @@ type DelegatingAuthenticationOptions struct {
 	// CustomRoundTripperFn allows for specifying a middleware function for custom HTTP behaviour for the authentication webhook client.
 	CustomRoundTripperFn transport.WrapperFunc
 
-	// DisableAnonymous gives user an option to disable Anonymous authentication.
-	DisableAnonymous bool
+	// Anonymous gives user an option to enable/disable Anonymous authentication.
+	Anonymous *apiserver.AnonymousAuthConfig
 }
 
 func NewDelegatingAuthenticationOptions() *DelegatingAuthenticationOptions {
@@ -238,6 +239,7 @@ func NewDelegatingAuthenticationOptions() *DelegatingAuthenticationOptions {
 		},
 		WebhookRetryBackoff: DefaultAuthWebhookRetryBackoff(),
 		TokenRequestTimeout: 10 * time.Second,
+		Anonymous:           &apiserver.AnonymousAuthConfig{Enabled: true},
 	}
 }
 
@@ -305,7 +307,7 @@ func (s *DelegatingAuthenticationOptions) ApplyTo(authenticationInfo *server.Aut
 	}
 
 	cfg := authenticatorfactory.DelegatingAuthenticatorConfig{
-		Anonymous:                !s.DisableAnonymous,
+		Anonymous:                &apiserver.AnonymousAuthConfig{Enabled: true},
 		CacheTTL:                 s.CacheTTL,
 		WebhookRetryBackoff:      s.WebhookRetryBackoff,
 		TokenAccessReviewTimeout: s.TokenRequestTimeout,