Add basic Authorization.

Added basic interface for authorizer implementations. Added default "authorize everything" and "authorize nothing implementations. Added authorization check immediately after authentication check. Added an integration test of authorization at the HTTP level of abstraction.
erikstmartin · Oct 31, 2014 · 55c2d6b · 55c2d6b
1 parent 893291d
commit 55c2d6b
Showing 9 changed files with 433 additions and 4 deletions.
diff --git a/cmd/apiserver/apiserver.go b/cmd/apiserver/apiserver.go
@@ -23,6 +23,7 @@ import (
 	"net"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/apiserver"
@@ -63,6 +64,7 @@ var (
 	healthCheckMinions    = flag.Bool("health_check_minions", true, "If true, health check minions and filter unhealthy ones. Default true.")
 	eventTTL              = flag.Duration("event_ttl", 48*time.Hour, "Amount of time to retain events. Default 2 days.")
 	tokenAuthFile         = flag.String("token_auth_file", "", "If set, the file that will be used to secure the API server via token authentication.")
+	authorizationMode     = flag.String("authorization_mode", "AlwaysAllow", "Selects how to do authorization.  One of: "+strings.Join(apiserver.AuthorizationModeChoices, ","))
 	etcdServerList        util.StringList
 	etcdConfigFile        = flag.String("etcd_config", "", "The config file for the etcd client. Mutually exclusive with -etcd_servers.")
 	corsAllowedOriginList util.StringList
@@ -159,6 +161,7 @@ func main() {
 		ReadOnlyPort:          *readOnlyPort,
 		ReadWritePort:         *port,
 		PublicAddress:         *publicAddressOverride,
+		AuthorizationMode:     *authorizationMode,
 	}
 	m := master.New(config)
 

diff --git a/cmd/integration/integration.go b/cmd/integration/integration.go
@@ -146,6 +146,7 @@ func startComponents(manifestURL string) (apiServerURL string) {
 		KubeletClient:     fakeKubeletClient{},
 		EnableLogsSupport: false,
 		APIPrefix:         "/api",
+		AuthorizationMode: "AlwaysAllow",
 
 		ReadWritePort: portNumber,
 		ReadOnlyPort:  portNumber,

diff --git a/hack/test-integration.sh b/hack/test-integration.sh
@@ -41,7 +41,7 @@ start_etcd
 echo ""
 echo "Integration test cases..."
 echo ""
-GOFLAGS="-tags 'integration no-docker'" \
+GOFLAGS="-tags 'integration no-docker' -test.v" \
   "${KUBE_ROOT}/hack/test-go.sh" test/integration
 
 echo ""

diff --git a/pkg/apiserver/authz.go b/pkg/apiserver/authz.go
@@ -0,0 +1,68 @@
+/*
+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 apiserver
+
+import (
+	"errors"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/authorizer"
+)
+
+// Attributes implements authorizer.Attributes interface.
+type Attributes struct {
+	// TODO: add fields and methods when authorizer.Attributes is completed.
+}
+
+// alwaysAllowAuthorizer is an implementation of authorizer.Attributes
+// which always says yes to an authorization request.
+// It is useful in tests and when using kubernetes in an open manner.
+type alwaysAllowAuthorizer struct{}
+
+func (alwaysAllowAuthorizer) Authorize(a authorizer.Attributes) (err error) {
+	return nil
+}
+
+// alwaysDenyAuthorizer is an implementation of authorizer.Attributes
+// which always says no to an authorization request.
+// It is useful in unit tests to force an operation to be forbidden.
+type alwaysDenyAuthorizer struct{}
+
+func (alwaysDenyAuthorizer) Authorize(a authorizer.Attributes) (err error) {
+	return errors.New("Everything is forbidden.")
+}
+
+const (
+	ModeAlwaysAllow string = "AlwaysAllow"
+	ModeAlwaysDeny  string = "AlwaysDeny"
+)
+
+// Keep this list in sync with constant list above.
+var AuthorizationModeChoices = []string{ModeAlwaysAllow, ModeAlwaysDeny}
+
+// NewAuthorizerFromAuthorizationConfig returns the right sort of authorizer.Authorizer
+// based on the authorizationMode xor an error.  authorizationMode should be one of AuthorizationModeChoices.
+func NewAuthorizerFromAuthorizationConfig(authorizationMode string) (authorizer.Authorizer, error) {
+	// Keep cases in sync with constant list above.
+	switch authorizationMode {
+	case ModeAlwaysAllow:
+		return new(alwaysAllowAuthorizer), nil
+	case ModeAlwaysDeny:
+		return new(alwaysDenyAuthorizer), nil
+	default:
+		return nil, errors.New("Unknown authorization mode")
+	}
+}
diff --git a/pkg/apiserver/handlers.go b/pkg/apiserver/handlers.go
@@ -23,6 +23,7 @@ import (
 	"runtime/debug"
 	"strings"
 
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/auth/authorizer"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/httplog"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/golang/glog"
@@ -118,3 +119,24 @@ func CORS(handler http.Handler, allowedOriginPatterns []*regexp.Regexp, allowedM
 		handler.ServeHTTP(w, req)
 	})
 }
+
+// RequestAttributeGetter is a function that extracts authorizer.Attributes from an http.Request
+type RequestAttributeGetter func(req *http.Request) (attribs authorizer.Attributes)
+
+// BasicAttributeGetter gets authorizer.Attributes from an http.Request.
+func BasicAttributeGetter(req *http.Request) (attribs authorizer.Attributes) {
+	// TODO: fill in attributes once attributes are defined.
+	return
+}
+
+// WithAuthorizationCheck passes all authorized requests on to handler, and returns a forbidden error otherwise.
+func WithAuthorizationCheck(handler http.Handler, getAttribs RequestAttributeGetter, a authorizer.Authorizer) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		err := a.Authorize(getAttribs(req))
+		if err == nil {
+			handler.ServeHTTP(w, req)
+			return
+		}
+		forbidden(w, req)
+	})
+}
diff --git a/pkg/auth/authorizer/interfaces.go b/pkg/auth/authorizer/interfaces.go
@@ -0,0 +1,30 @@
+/*
+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 authorizer
+
+// Attributes is an interface used by an Authorizer to get information about a request
+// that is used to make an authorization decision.
+type Attributes interface {
+	// TODO: add attribute getter functions, e.g. GetUserName(), per #1430.
+}
+
+// Authorizer makes an authorization decision based on information gained by making
+// zero or more calls to methods of the Attributes interface.  It returns nil when an action is
+// authorized, otherwise it returns an error.
+type Authorizer interface {
+	Authorize(a Attributes) (err error)
+}
diff --git a/pkg/master/master.go b/pkg/master/master.go
@@ -66,6 +66,7 @@ type Config struct {
 	APIPrefix             string
 	CorsAllowedOriginList util.StringList
 	TokenAuthFile         string
+	AuthorizationMode     string
 
 	// Number of masters running; all masters must be started with the
 	// same value for this field. (Numbers > 1 currently untested.)
@@ -101,6 +102,7 @@ type Master struct {
 	apiPrefix             string
 	corsAllowedOriginList util.StringList
 	tokenAuthFile         string
+	authorizationzMode    string
 	masterCount           int
 
 	// "Outputs"
@@ -220,9 +222,11 @@ func New(c *Config) *Master {
 		apiPrefix:             c.APIPrefix,
 		corsAllowedOriginList: c.CorsAllowedOriginList,
 		tokenAuthFile:         c.TokenAuthFile,
-		masterCount:           c.MasterCount,
-		readOnlyServer:        net.JoinHostPort(c.PublicAddress, strconv.Itoa(int(c.ReadOnlyPort))),
-		readWriteServer:       net.JoinHostPort(c.PublicAddress, strconv.Itoa(int(c.ReadWritePort))),
+		authorizationzMode:    c.AuthorizationMode,
+
+		masterCount:     c.MasterCount,
+		readOnlyServer:  net.JoinHostPort(c.PublicAddress, strconv.Itoa(int(c.ReadOnlyPort))),
+		readWriteServer: net.JoinHostPort(c.PublicAddress, strconv.Itoa(int(c.ReadWritePort))),
 	}
 	m.masterServices = util.NewRunner(m.serviceWriterLoop, m.roServiceWriterLoop)
 	m.init(c)
@@ -310,6 +314,14 @@ func (m *Master) init(c *Config) {
 		handler = apiserver.CORS(handler, allowedOriginRegexps, nil, nil, "true")
 	}
 
+	// Install Authorizer
+	authorizer, err := apiserver.NewAuthorizerFromAuthorizationConfig(m.authorizationzMode)
+	if err != nil {
+		glog.Fatal(err)
+	}
+	handler = apiserver.WithAuthorizationCheck(handler, apiserver.BasicAttributeGetter, authorizer)
+
+	// Install Authenticator
 	if authenticator != nil {
 		handler = handlers.NewRequestAuthenticator(userContexts, authenticator, handlers.Unauthorized, handler)
 	}