add other impersonation fields to transport

pkg/client/restclient/config.go

@@ -70,8 +70,8 @@ type Config struct {
 	// TODO: demonstrate an OAuth2 compatible client.
 	BearerToken string
 
-	// Impersonate is the username that this RESTClient will impersonate
-	Impersonate string
+	// Impersonate is the configuration that RESTClient will use for impersonation.
+	Impersonate ImpersonationConfig
 
 	// Server requires plugin-specified authentication.
 	AuthProvider *clientcmdapi.AuthProviderConfig
@@ -118,6 +118,17 @@ type Config struct {
 	// Version string
 }
 
+// ImpersonationConfig has all the available impersonation options
+type ImpersonationConfig struct {
+	// UserName is the username to impersonate on each request.
+	UserName string
+	// Groups are the groups to impersonate on each request.
+	Groups []string
+	// Extra is a free-form field which can be used to link some authentication information
+	// to authorization information.  This field allows you to impersonate it.
+	Extra map[string][]string
+}
+
 // TLSClientConfig contains settings to enable transport layer security
 type TLSClientConfig struct {
 	// Server requires TLS client certificate authentication

pkg/client/restclient/config_test.go

@@ -205,7 +205,7 @@ func TestAnonymousConfig(t *testing.T) {
 
 		// this is the list of known security related fields, add to this list if a new field
 		// is added to Config, update AnonymousClientConfig to preserve the field otherwise.
-		expected.Impersonate = ""
+		expected.Impersonate = ImpersonationConfig{}
 		expected.BearerToken = ""
 		expected.Username = ""
 		expected.Password = ""

pkg/client/restclient/transport.go

@@ -89,6 +89,10 @@ func (c *Config) TransportConfig() (*transport.Config, error) {
 		Username:    c.Username,
 		Password:    c.Password,
 		BearerToken: c.BearerToken,
-		Impersonate: c.Impersonate,
+		Impersonate: transport.ImpersonationConfig{
+			UserName: c.Impersonate.UserName,
+			Groups:   c.Impersonate.Groups,
+			Extra:    c.Impersonate.Extra,
+		},
 	}, nil
 }

pkg/client/transport/config.go

@@ -34,8 +34,8 @@ type Config struct {
 	// Bearer token for authentication
 	BearerToken string
 
-	// Impersonate is the username that this Config will impersonate
-	Impersonate string
+	// Impersonate is the config that this Config will impersonate using
+	Impersonate ImpersonationConfig
 
 	// Transport may be used for custom HTTP behavior. This attribute may
 	// not be specified with the TLS client certificate options. Use
@@ -50,6 +50,16 @@ type Config struct {
 	WrapTransport func(rt http.RoundTripper) http.RoundTripper
 }
 
+// ImpersonationConfig has all the available impersonation options
+type ImpersonationConfig struct {
+	// UserName matches user.Info.GetName()
+	UserName string
+	// Groups matches user.Info.GetGroups()
+	Groups []string
+	// Extra matches user.Info.GetExtra()
+	Extra map[string][]string
+}
+
 // HasCA returns whether the configuration has a certificate authority or not.
 func (c *Config) HasCA() bool {
 	return len(c.TLS.CAData) > 0 || len(c.TLS.CAFile) > 0

pkg/client/transport/round_trippers.go

@@ -48,7 +48,9 @@ func HTTPWrappersForConfig(config *Config, rt http.RoundTripper) (http.RoundTrip
 	if len(config.UserAgent) > 0 {
 		rt = NewUserAgentRoundTripper(config.UserAgent, rt)
 	}
-	if len(config.Impersonate) > 0 {
+	if len(config.Impersonate.UserName) > 0 ||
+		len(config.Impersonate.Groups) > 0 ||
+		len(config.Impersonate.Extra) > 0 {
 		rt = NewImpersonatingRoundTripper(config.Impersonate, rt)
 	}
 	return rt, nil
@@ -133,22 +135,53 @@ func (rt *basicAuthRoundTripper) CancelRequest(req *http.Request) {
 
 func (rt *basicAuthRoundTripper) WrappedRoundTripper() http.RoundTripper { return rt.rt }
 
+// These correspond to the headers used in pkg/apis/authentication.  We don't want the package dependency,
+// but you must not change the values.
+const (
+	// ImpersonateUserHeader is used to impersonate a particular user during an API server request
+	ImpersonateUserHeader = "Impersonate-User"
+
+	// ImpersonateGroupHeader is used to impersonate a particular group during an API server request.
+	// It can be repeated multiplied times for multiple groups.
+	ImpersonateGroupHeader = "Impersonate-Group"
+
+	// ImpersonateUserExtraHeaderPrefix is a prefix for a header used to impersonate an entry in the
+	// extra map[string][]string for user.Info.  The key for the `extra` map is suffix.
+	// The same key can be repeated multiple times to have multiple elements in the slice under a single key.
+	// For instance:
+	// Impersonate-Extra-Foo: one
+	// Impersonate-Extra-Foo: two
+	// results in extra["Foo"] = []string{"one", "two"}
+	ImpersonateUserExtraHeaderPrefix = "Impersonate-Extra-"
+)
+
 type impersonatingRoundTripper struct {
-	impersonate string
+	impersonate ImpersonationConfig
 	delegate    http.RoundTripper
 }
 
 // NewImpersonatingRoundTripper will add an Act-As header to a request unless it has already been set.
-func NewImpersonatingRoundTripper(impersonate string, delegate http.RoundTripper) http.RoundTripper {
+func NewImpersonatingRoundTripper(impersonate ImpersonationConfig, delegate http.RoundTripper) http.RoundTripper {
 	return &impersonatingRoundTripper{impersonate, delegate}
 }
 
 func (rt *impersonatingRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	if len(req.Header.Get("Impersonate-User")) != 0 {
+	// use the user header as marker for the rest.
+	if len(req.Header.Get(ImpersonateUserHeader)) != 0 {
 		return rt.delegate.RoundTrip(req)
 	}
 	req = cloneRequest(req)
-	req.Header.Set("Impersonate-User", rt.impersonate)
+	req.Header.Set(ImpersonateUserHeader, rt.impersonate.UserName)
+
+	for _, group := range rt.impersonate.Groups {
+		req.Header.Add(ImpersonateGroupHeader, group)
+	}
+	for k, vv := range rt.impersonate.Extra {
+		for _, v := range vv {
+			req.Header.Add(ImpersonateUserExtraHeaderPrefix+k, v)
+		}
+	}
+
 	return rt.delegate.RoundTrip(req)
 }
 

pkg/client/transport/round_trippers_test.go

@@ -18,6 +18,7 @@ package transport
 
 import (
 	"net/http"
+	"reflect"
 	"testing"
 )
 
@@ -99,3 +100,58 @@ func TestUserAgentRoundTripper(t *testing.T) {
 		t.Errorf("unexpected user agent header: %#v", rt.Request)
 	}
 }
+
+func TestImpersonationRoundTripper(t *testing.T) {
+	tcs := []struct {
+		name                string
+		impersonationConfig ImpersonationConfig
+		expected            map[string][]string
+	}{
+		{
+			name: "all",
+			impersonationConfig: ImpersonationConfig{
+				UserName: "user",
+				Groups:   []string{"one", "two"},
+				Extra: map[string][]string{
+					"first":  {"A", "a"},
+					"second": {"B", "b"},
+				},
+			},
+			expected: map[string][]string{
+				ImpersonateUserHeader:                       {"user"},
+				ImpersonateGroupHeader:                      {"one", "two"},
+				ImpersonateUserExtraHeaderPrefix + "First":  {"A", "a"},
+				ImpersonateUserExtraHeaderPrefix + "Second": {"B", "b"},
+			},
+		},
+	}
+
+	for _, tc := range tcs {
+		rt := &testRoundTripper{}
+		req := &http.Request{
+			Header: make(http.Header),
+		}
+		NewImpersonatingRoundTripper(tc.impersonationConfig, rt).RoundTrip(req)
+
+		for k, v := range rt.Request.Header {
+			expected, ok := tc.expected[k]
+			if !ok {
+				t.Errorf("%v missing %v=%v", tc.name, k, v)
+				continue
+			}
+			if !reflect.DeepEqual(expected, v) {
+				t.Errorf("%v expected %v: %v, got %v", tc.name, k, expected, v)
+			}
+		}
+		for k, v := range tc.expected {
+			expected, ok := rt.Request.Header[k]
+			if !ok {
+				t.Errorf("%v missing %v=%v", tc.name, k, v)
+				continue
+			}
+			if !reflect.DeepEqual(expected, v) {
+				t.Errorf("%v expected %v: %v, got %v", tc.name, k, expected, v)
+			}
+		}
+	}
+}

pkg/client/unversioned/clientcmd/client_config.go

@@ -144,7 +144,7 @@ func (config *DirectClientConfig) ClientConfig() (*restclient.Config, error) {
 		clientConfig.Host = u.String()
 	}
 	if len(configAuthInfo.Impersonate) > 0 {
-		clientConfig.Impersonate = configAuthInfo.Impersonate
+		clientConfig.Impersonate = restclient.ImpersonationConfig{UserName: configAuthInfo.Impersonate}
 	}
 
 	// only try to read the auth information if we are secure
@@ -215,7 +215,7 @@ func getUserIdentificationPartialConfig(configAuthInfo clientcmdapi.AuthInfo, fa
 		mergedConfig.BearerToken = string(tokenBytes)
 	}
 	if len(configAuthInfo.Impersonate) > 0 {
-		mergedConfig.Impersonate = configAuthInfo.Impersonate
+		mergedConfig.Impersonate = restclient.ImpersonationConfig{UserName: configAuthInfo.Impersonate}
 	}
 	if len(configAuthInfo.ClientCertificate) > 0 || len(configAuthInfo.ClientCertificateData) > 0 {
 		mergedConfig.CertFile = configAuthInfo.ClientCertificate