genericapiserver: move packages

Towards a sane k8s.io/apiserver package structure.

pkg/genericapiserver/server/options/authentication.go

@@ -0,0 +1,175 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package options
+
+import (
+	"time"
+
+	"github.com/spf13/pflag"
+
+	authenticationclient "k8s.io/client-go/kubernetes/typed/authentication/v1beta1"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/kubernetes/pkg/genericapiserver/authenticator"
+)
+
+type RequestHeaderAuthenticationOptions struct {
+	UsernameHeaders     []string
+	GroupHeaders        []string
+	ExtraHeaderPrefixes []string
+	ClientCAFile        string
+	AllowedNames        []string
+}
+
+func (s *RequestHeaderAuthenticationOptions) AddFlags(fs *pflag.FlagSet) {
+	fs.StringSliceVar(&s.UsernameHeaders, "requestheader-username-headers", s.UsernameHeaders, ""+
+		"List of request headers to inspect for usernames. X-Remote-User is common.")
+
+	fs.StringSliceVar(&s.GroupHeaders, "requestheader-group-headers", s.GroupHeaders, ""+
+		"List of request headers to inspect for groups. X-Remote-Group is suggested.")
+
+	fs.StringSliceVar(&s.ExtraHeaderPrefixes, "requestheader-extra-headers-prefix", s.ExtraHeaderPrefixes, ""+
+		"List of request header prefixes to inspect. X-Remote-Extra- is suggested.")
+
+	fs.StringVar(&s.ClientCAFile, "requestheader-client-ca-file", s.ClientCAFile, ""+
+		"Root certificate bundle to use to verify client certificates on incoming requests "+
+		"before trusting usernames in headers specified by --requestheader-username-headers")
+
+	fs.StringSliceVar(&s.AllowedNames, "requestheader-allowed-names", s.AllowedNames, ""+
+		"List of client certificate common names to allow to provide usernames in headers "+
+		"specified by --requestheader-username-headers. If empty, any client certificate validated "+
+		"by the authorities in --requestheader-client-ca-file is allowed.")
+}
+
+// ToAuthenticationRequestHeaderConfig returns a RequestHeaderConfig config object for these options
+// if necessary, nil otherwise.
+func (s *RequestHeaderAuthenticationOptions) ToAuthenticationRequestHeaderConfig() *authenticator.RequestHeaderConfig {
+	if len(s.UsernameHeaders) == 0 {
+		return nil
+	}
+
+	return &authenticator.RequestHeaderConfig{
+		UsernameHeaders:     s.UsernameHeaders,
+		GroupHeaders:        s.GroupHeaders,
+		ExtraHeaderPrefixes: s.ExtraHeaderPrefixes,
+		ClientCA:            s.ClientCAFile,
+		AllowedClientNames:  s.AllowedNames,
+	}
+}
+
+type ClientCertAuthenticationOptions struct {
+	// ClientCA is the certificate bundle for all the signers that you'll recognize for incoming client certificates
+	ClientCA string
+}
+
+func (s *ClientCertAuthenticationOptions) AddFlags(fs *pflag.FlagSet) {
+	fs.StringVar(&s.ClientCA, "client-ca-file", s.ClientCA, ""+
+		"If set, any request presenting a client certificate signed by one of "+
+		"the authorities in the client-ca-file is authenticated with an identity "+
+		"corresponding to the CommonName of the client certificate.")
+}
+
+// DelegatingAuthenticationOptions provides an easy way for composing API servers to delegate their authentication to
+// 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.
+	RemoteKubeConfigFile string
+
+	// 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{
+		// 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-"},
+		},
+	}
+}
+
+func (s *DelegatingAuthenticationOptions) Validate() []error {
+	allErrors := []error{}
+	return allErrors
+}
+
+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.")
+
+	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() (authenticator.DelegatingAuthenticatorConfig, error) {
+	tokenClient, err := s.newTokenAccessReview()
+	if err != nil {
+		return authenticator.DelegatingAuthenticatorConfig{}, err
+	}
+
+	ret := authenticator.DelegatingAuthenticatorConfig{
+		Anonymous:               true,
+		TokenAccessReviewClient: tokenClient,
+		CacheTTL:                s.CacheTTL,
+		ClientCAFile:            s.ClientCert.ClientCA,
+		RequestHeaderConfig:     s.RequestHeader.ToAuthenticationRequestHeaderConfig(),
+	}
+	return ret, nil
+}
+
+func (s *DelegatingAuthenticationOptions) newTokenAccessReview() (authenticationclient.TokenReviewInterface, error) {
+	var clientConfig *rest.Config
+	var err error
+	if len(s.RemoteKubeConfigFile) > 0 {
+		loadingRules := &clientcmd.ClientConfigLoadingRules{ExplicitPath: s.RemoteKubeConfigFile}
+		loader := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{})
+
+		clientConfig, err = loader.ClientConfig()
+
+	} else {
+		// without the remote kubeconfig file, try to use the in-cluster config.  Most addon API servers will
+		// use this path
+		clientConfig, err = rest.InClusterConfig()
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	// set high qps/burst limits since this will effectively limit API server responsiveness
+	clientConfig.QPS = 200
+	clientConfig.Burst = 400
+
+	client, err := authenticationclient.NewForConfig(clientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return client.TokenReviews(), nil
+}