Add simple Bearer authenticator filter for Kube

* Default file based implementation
* Define some simple interfaces
* Add -token_auth_file to apiserver that will start the apiserver
  with a request filter for tokens

pkg/auth/handlers/handlers.go

@@ -0,0 +1,95 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 handlers
+
+import (
+	"net/http"
+	"sync"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/authenticator"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/user"
+	"github.com/golang/glog"
+)
+
+// RequestContext is the interface used to associate a user with an http Request.
+type RequestContext interface {
+	Set(*http.Request, user.Info)
+	Remove(*http.Request)
+}
+
+// NewRequestAuthenticator creates an http handler that tries to authenticate the given request as a user, and then
+// stores any such user found onto the provided context for the request. If authentication fails or returns an error
+// the failed handler is used. On success, handler is invoked to serve the request.
+func NewRequestAuthenticator(context RequestContext, auth authenticator.Request, failed http.Handler, handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		user, ok, err := auth.AuthenticateRequest(req)
+		if err != nil || !ok {
+			if err != nil {
+				glog.Errorf("Unable to authenticate the request due to an error: %v", err)
+			}
+			failed.ServeHTTP(w, req)
+			return
+		}
+
+		context.Set(req, user)
+		defer context.Remove(req)
+
+		handler.ServeHTTP(w, req)
+	})
+}
+
+var Unauthorized http.HandlerFunc = unauthorized
+
+// unauthorized serves an unauthorized message to clients.
+func unauthorized(w http.ResponseWriter, req *http.Request) {
+	http.Error(w, "Unauthorized", http.StatusUnauthorized)
+}
+
+// UserRequestContext allows different levels of a call stack to store/retrieve info about the
+// current user associated with an http.Request.
+type UserRequestContext struct {
+	requests map[*http.Request]user.Info
+	lock     sync.Mutex
+}
+
+// NewUserRequestContext provides a map for storing and retrieving users associated with requests.
+// Be sure to pair each `context.Set(req, user)` call with a `defer context.Remove(req)` call or
+// you will leak requests. It implements the RequestContext interface.
+func NewUserRequestContext() *UserRequestContext {
+	return &UserRequestContext{
+		requests: make(map[*http.Request]user.Info),
+	}
+}
+
+func (c *UserRequestContext) Get(req *http.Request) (user.Info, bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	user, ok := c.requests[req]
+	return user, ok
+}
+
+func (c *UserRequestContext) Set(req *http.Request, user user.Info) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.requests[req] = user
+}
+
+func (c *UserRequestContext) Remove(req *http.Request) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	delete(c.requests, req)
+}

pkg/auth/handlers/handlers_test.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 handlers
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/authenticator"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/user"
+)
+
+func TestAuthenticateRequest(t *testing.T) {
+	success := make(chan struct{})
+	context := NewUserRequestContext()
+	auth := NewRequestAuthenticator(
+		context,
+		authenticator.RequestFunc(func(req *http.Request) (user.Info, bool, error) {
+			return &user.DefaultInfo{Name: "user"}, true, nil
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
+			t.Errorf("unexpected call to failed")
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, req *http.Request) {
+			if user, ok := context.Get(req); user == nil || !ok {
+				t.Errorf("no user stored on context: %#v", context)
+			}
+			close(success)
+		}),
+	)
+
+	auth.ServeHTTP(httptest.NewRecorder(), &http.Request{})
+
+	<-success
+	if len(context.requests) > 0 {
+		t.Errorf("context should have no stored requests", context)
+	}
+}
+
+func TestAuthenticateRequestFailed(t *testing.T) {
+	failed := make(chan struct{})
+	context := NewUserRequestContext()
+	auth := NewRequestAuthenticator(
+		context,
+		authenticator.RequestFunc(func(req *http.Request) (user.Info, bool, error) {
+			return nil, false, nil
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
+			close(failed)
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, req *http.Request) {
+			t.Errorf("unexpected call to handler")
+		}),
+	)
+
+	auth.ServeHTTP(httptest.NewRecorder(), &http.Request{})
+
+	<-failed
+	if len(context.requests) > 0 {
+		t.Errorf("context should have no stored requests", context)
+	}
+}
+
+func TestAuthenticateRequestError(t *testing.T) {
+	failed := make(chan struct{})
+	context := NewUserRequestContext()
+	auth := NewRequestAuthenticator(
+		context,
+		authenticator.RequestFunc(func(req *http.Request) (user.Info, bool, error) {
+			return nil, false, errors.New("failure")
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
+			close(failed)
+		}),
+		http.HandlerFunc(func(_ http.ResponseWriter, req *http.Request) {
+			t.Errorf("unexpected call to handler")
+		}),
+	)
+
+	auth.ServeHTTP(httptest.NewRecorder(), &http.Request{})
+
+	<-failed
+	if len(context.requests) > 0 {
+		t.Errorf("context should have no stored requests", context)
+	}
+}