update delegating auth to include front-proxy

cmd/kube-apiserver/app/server.go

@@ -96,14 +96,14 @@ func Run(s *options.ServerRunOptions) error {
 
 	genericapiserver.DefaultAndValidateRunOptions(s.GenericServerRunOptions)
 
-	genericConfig, err := genericapiserver.NewConfig(). // create the new config
+	genericConfig := genericapiserver.NewConfig(). // create the new config
 							ApplyOptions(s.GenericServerRunOptions). // apply the options selected
-								ApplyInsecureServingOptions(s.InsecureServing).
-								ApplyAuthenticationOptions(s.Authentication).
-								ApplySecureServingOptions(s.SecureServing)
-	if err != nil {
+							ApplyInsecureServingOptions(s.InsecureServing)
+
+	if _, err := genericConfig.ApplySecureServingOptions(s.SecureServing); err != nil {
 		return fmt.Errorf("failed to configure https: %s", err)
 	}
+	genericConfig.ApplyAuthenticationOptions(s.Authentication)
 
 	capabilities.Initialize(capabilities.Capabilities{
 		AllowPrivileged: s.AllowPrivileged,

examples/apiserver/apiserver.go

@@ -99,14 +99,14 @@ func (serverOptions *ServerRunOptions) Run(stopCh <-chan struct{}) error {
 		glog.Fatalf("Error creating self-signed certificates: %v", err)
 	}
 
-	config, err := genericapiserver.NewConfig().
+	config := genericapiserver.NewConfig().
 		ApplyOptions(serverOptions.GenericServerRunOptions).
-		ApplyInsecureServingOptions(serverOptions.InsecureServing).
-		ApplyAuthenticationOptions(serverOptions.Authentication).
-		ApplySecureServingOptions(serverOptions.SecureServing)
-	if err != nil {
+		ApplyInsecureServingOptions(serverOptions.InsecureServing)
+
+	if _, err := config.ApplySecureServingOptions(serverOptions.SecureServing); err != nil {
 		return fmt.Errorf("failed to configure https: %s", err)
 	}
+	config.ApplyAuthenticationOptions(serverOptions.Authentication)
 
 	config.Authorizer = authorizer.NewAlwaysAllowAuthorizer()
 	s, err := config.Complete().New()

federation/cmd/federation-apiserver/app/server.go

@@ -78,14 +78,14 @@ func Run(s *options.ServerRunOptions) error {
 	}
 
 	genericapiserver.DefaultAndValidateRunOptions(s.GenericServerRunOptions)
-	genericConfig, err := genericapiserver.NewConfig(). // create the new config
+	genericConfig := genericapiserver.NewConfig(). // create the new config
 							ApplyOptions(s.GenericServerRunOptions). // apply the options selected
-								ApplyInsecureServingOptions(s.InsecureServing).
-								ApplyAuthenticationOptions(s.Authentication).
-								ApplySecureServingOptions(s.SecureServing)
-	if err != nil {
+							ApplyInsecureServingOptions(s.InsecureServing)
+
+	if _, err := genericConfig.ApplySecureServingOptions(s.SecureServing); err != nil {
 		return fmt.Errorf("failed to configure https: %s", err)
 	}
+	genericConfig.ApplyAuthenticationOptions(s.Authentication)
 
 	// TODO: register cluster federation resources here.
 	resourceConfig := genericapiserver.NewResourceConfig()

pkg/apiserver/authenticator/delegating.go

@@ -30,6 +30,7 @@ import (
 	authenticationclient "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_5/typed/authentication/v1beta1"
 	"k8s.io/kubernetes/pkg/util/cert"
 	"k8s.io/kubernetes/plugin/pkg/auth/authenticator/request/anonymous"
+	"k8s.io/kubernetes/plugin/pkg/auth/authenticator/request/headerrequest"
 	unionauth "k8s.io/kubernetes/plugin/pkg/auth/authenticator/request/union"
 	"k8s.io/kubernetes/plugin/pkg/auth/authenticator/request/x509"
 	webhooktoken "k8s.io/kubernetes/plugin/pkg/auth/authenticator/token/webhook"
@@ -47,12 +48,30 @@ type DelegatingAuthenticatorConfig struct {
 
 	// ClientCAFile is the CA bundle file used to authenticate client certificates
 	ClientCAFile string
+
+	RequestHeaderConfig *RequestHeaderConfig
 }
 
 func (c DelegatingAuthenticatorConfig) New() (authenticator.Request, *spec.SecurityDefinitions, error) {
 	authenticators := []authenticator.Request{}
 	securityDefinitions := spec.SecurityDefinitions{}
 
+	// front-proxy first, then remote
+	// Add the front proxy authenticator if requested
+	if c.RequestHeaderConfig != nil {
+		requestHeaderAuthenticator, err := headerrequest.NewSecure(
+			c.RequestHeaderConfig.ClientCA,
+			c.RequestHeaderConfig.AllowedClientNames,
+			c.RequestHeaderConfig.UsernameHeaders,
+			c.RequestHeaderConfig.GroupHeaders,
+			c.RequestHeaderConfig.ExtraHeaderPrefixes,
+		)
+		if err != nil {
+			return nil, nil, err
+		}
+		authenticators = append(authenticators, requestHeaderAuthenticator)
+	}
+
 	// x509 client cert auth
 	if len(c.ClientCAFile) > 0 {
 		clientCAs, err := cert.NewPool(c.ClientCAFile)
@@ -93,5 +112,4 @@ func (c DelegatingAuthenticatorConfig) New() (authenticator.Request, *spec.Secur
 		authenticator = unionauth.NewFailOnError(authenticator, anonymous.NewAuthenticator())
 	}
 	return authenticator, &securityDefinitions, nil
-
 }

pkg/genericapiserver/options/authentication.go

@@ -350,7 +350,8 @@ func (s *ClientCertAuthenticationOptions) AddFlags(fs *pflag.FlagSet) {
 }
 
 // DelegatingAuthenticationOptions provides an easy way for composing API servers to delegate their authentication to
-// the root kube API server
+// the root kube API server.  The API federator will act as
+// a front proxy and direction connections will be able to delegate to the core kube API server
 type DelegatingAuthenticationOptions struct {
 	// RemoteKubeConfigFile is the file to use to connect to a "normal" kube API server which hosts the
 	// TokenAccessReview.authentication.k8s.io endpoint for checking tokens.
@@ -358,11 +359,21 @@ type DelegatingAuthenticationOptions struct {
 
 	// CacheTTL is the length of time that a token authentication answer will be cached.
 	CacheTTL time.Duration
+
+	ClientCert    ClientCertAuthenticationOptions
+	RequestHeader RequestHeaderAuthenticationOptions
 }
 
 func NewDelegatingAuthenticationOptions() *DelegatingAuthenticationOptions {
 	return &DelegatingAuthenticationOptions{
-		CacheTTL: 5 * time.Minute,
+		// very low for responsiveness, but high enough to handle storms
+		CacheTTL:   10 * time.Second,
+		ClientCert: ClientCertAuthenticationOptions{},
+		RequestHeader: RequestHeaderAuthenticationOptions{
+			UsernameHeaders:     []string{"x-remote-user"},
+			GroupHeaders:        []string{"x-remote-group"},
+			ExtraHeaderPrefixes: []string{"x-remote-extra-"},
+		},
 	}
 }
 
@@ -374,10 +385,16 @@ func (s *DelegatingAuthenticationOptions) Validate() []error {
 func (s *DelegatingAuthenticationOptions) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.RemoteKubeConfigFile, "authentication-kubeconfig", s.RemoteKubeConfigFile, ""+
 		"kubeconfig file pointing at the 'core' kubernetes server with enough rights to create "+
-		" tokenaccessreviews.authentication.k8s.io.")
+		"tokenaccessreviews.authentication.k8s.io.")
+
+	fs.DurationVar(&s.CacheTTL, "authentication-token-webhook-cache-ttl", s.CacheTTL,
+		"The duration to cache responses from the webhook token authenticator.")
+
+	s.ClientCert.AddFlags(fs)
+	s.RequestHeader.AddFlags(fs)
 }
 
-func (s *DelegatingAuthenticationOptions) ToAuthenticationConfig(clientCAFile string) (authenticator.DelegatingAuthenticatorConfig, error) {
+func (s *DelegatingAuthenticationOptions) ToAuthenticationConfig() (authenticator.DelegatingAuthenticatorConfig, error) {
 	tokenClient, err := s.newTokenAccessReview()
 	if err != nil {
 		return authenticator.DelegatingAuthenticatorConfig{}, err
@@ -387,7 +404,8 @@ func (s *DelegatingAuthenticationOptions) ToAuthenticationConfig(clientCAFile st
 		Anonymous:               true,
 		TokenAccessReviewClient: tokenClient,
 		CacheTTL:                s.CacheTTL,
-		ClientCAFile:            clientCAFile,
+		ClientCAFile:            s.ClientCert.ClientCA,
+		RequestHeaderConfig:     s.RequestHeader.ToAuthenticationRequestHeaderConfig(),
 	}
 	return ret, nil
 }