Provide current namespace to InClusterConfig

pkg/api/types.go

@@ -2218,6 +2218,8 @@ const (
 	ServiceAccountKubeconfigKey = "kubernetes.kubeconfig"
 	// ServiceAccountRootCAKey is the key of the optional root certificate authority for SecretTypeServiceAccountToken secrets
 	ServiceAccountRootCAKey = "ca.crt"
+	// ServiceAccountNamespaceKey is the key of the optional namespace to use as the default for namespaced API calls
+	ServiceAccountNamespaceKey = "namespace"
 
 	// SecretTypeDockercfg contains a dockercfg file that follows the same format rules as ~/.dockercfg
 	//

pkg/api/v1/types.go

@@ -2685,6 +2685,8 @@ const (
 	ServiceAccountKubeconfigKey = "kubernetes.kubeconfig"
 	// ServiceAccountRootCAKey is the key of the optional root certificate authority for SecretTypeServiceAccountToken secrets
 	ServiceAccountRootCAKey = "ca.crt"
+	// ServiceAccountNamespaceKey is the key of the optional namespace to use as the default for namespaced API calls
+	ServiceAccountNamespaceKey = "namespace"
 
 	// SecretTypeDockercfg contains a dockercfg file that follows the same format rules as ~/.dockercfg
 	//

pkg/client/unversioned/clientcmd/client_config.go

@@ -19,8 +19,10 @@ package clientcmd
 import (
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/url"
 	"os"
+	"strings"
 
 	"github.com/golang/glog"
 	"github.com/imdario/mergo"
@@ -325,12 +327,19 @@ func (inClusterClientConfig) ClientConfig() (*client.Config, error) {
 }
 
 func (inClusterClientConfig) Namespace() (string, error) {
-	// TODO: generic way to figure out what namespace you are running in?
+	// This way assumes you've set the POD_NAMESPACE environment variable using the downward API.
-	// This way assumes you've set the POD_NAMESPACE environment variable
+	// This check has to be done first for backwards compatibility with the way InClusterConfig was originally set up
-	// using the downward API.
 	if ns := os.Getenv("POD_NAMESPACE"); ns != "" {
 		return ns, nil
 	}
+
+	// Fall back to the namespace associated with the service account token, if available
+	if data, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace"); err == nil {
+		if ns := strings.TrimSpace(string(data)); len(ns) > 0 {
+			return ns, nil
+		}
+	}
+
 	return "default", nil
 }
 

pkg/controller/serviceaccount/tokens_controller.go

@@ -325,6 +325,7 @@ func (e *TokensController) createSecret(serviceAccount *api.ServiceAccount) erro
 		return err
 	}
 	secret.Data[api.ServiceAccountTokenKey] = []byte(token)
+	secret.Data[api.ServiceAccountNamespaceKey] = []byte(serviceAccount.Namespace)
 	if e.rootCA != nil && len(e.rootCA) > 0 {
 		secret.Data[api.ServiceAccountRootCAKey] = e.rootCA
 	}
@@ -364,10 +365,12 @@ func (e *TokensController) generateTokenIfNeeded(serviceAccount *api.ServiceAcco
 	caData := secret.Data[api.ServiceAccountRootCAKey]
 	needsCA := len(e.rootCA) > 0 && bytes.Compare(caData, e.rootCA) != 0
 
+	needsNamespace := len(secret.Data[api.ServiceAccountNamespaceKey]) == 0
+
 	tokenData := secret.Data[api.ServiceAccountTokenKey]
 	needsToken := len(tokenData) == 0
 
-	if !needsCA && !needsToken {
+	if !needsCA && !needsToken && !needsNamespace {
 		return nil
 	}
 
@@ -375,6 +378,10 @@ func (e *TokensController) generateTokenIfNeeded(serviceAccount *api.ServiceAcco
 	if needsCA {
 		secret.Data[api.ServiceAccountRootCAKey] = e.rootCA
 	}
+	// Set the namespace
+	if needsNamespace {
+		secret.Data[api.ServiceAccountNamespaceKey] = []byte(secret.Namespace)
+	}
 
 	// Generate the token
 	if needsToken {

pkg/controller/serviceaccount/tokens_controller_test.go

@@ -115,8 +115,9 @@ func createdTokenSecret() *api.Secret {
 		},
 		Type: api.SecretTypeServiceAccountToken,
 		Data: map[string][]byte{
-			"token":  []byte("ABC"),
+			"token":     []byte("ABC"),
-			"ca.crt": []byte("CA Data"),
+			"ca.crt":    []byte("CA Data"),
+			"namespace": []byte("default"),
 		},
 	}
 }
@@ -136,8 +137,9 @@ func serviceAccountTokenSecret() *api.Secret {
 		},
 		Type: api.SecretTypeServiceAccountToken,
 		Data: map[string][]byte{
-			"token":  []byte("ABC"),
+			"token":     []byte("ABC"),
-			"ca.crt": []byte("CA Data"),
+			"ca.crt":    []byte("CA Data"),
+			"namespace": []byte("default"),
 		},
 	}
 }
@@ -163,6 +165,20 @@ func serviceAccountTokenSecretWithCAData(data []byte) *api.Secret {
 	return secret
 }
 
+// serviceAccountTokenSecretWithoutNamespaceData returns an existing ServiceAccountToken secret that lacks namespace data
+func serviceAccountTokenSecretWithoutNamespaceData() *api.Secret {
+	secret := serviceAccountTokenSecret()
+	delete(secret.Data, api.ServiceAccountNamespaceKey)
+	return secret
+}
+
+// serviceAccountTokenSecretWithNamespaceData returns an existing ServiceAccountToken secret with the specified namespace data
+func serviceAccountTokenSecretWithNamespaceData(data []byte) *api.Secret {
+	secret := serviceAccountTokenSecret()
+	secret.Data[api.ServiceAccountNamespaceKey] = data
+	return secret
+}
+
 func TestTokenCreation(t *testing.T) {
 	testcases := map[string]struct {
 		ClientObjects []runtime.Object
@@ -379,6 +395,24 @@ func TestTokenCreation(t *testing.T) {
 				core.NewUpdateAction("secrets", api.NamespaceDefault, serviceAccountTokenSecret()),
 			},
 		},
+		"added token secret without namespace data": {
+			ClientObjects:          []runtime.Object{serviceAccountTokenSecretWithoutNamespaceData()},
+			ExistingServiceAccount: serviceAccount(tokenSecretReferences()),
+
+			AddedSecret: serviceAccountTokenSecretWithoutNamespaceData(),
+			ExpectedActions: []core.Action{
+				core.NewUpdateAction("secrets", api.NamespaceDefault, serviceAccountTokenSecret()),
+			},
+		},
+		"added token secret with custom namespace data": {
+			ClientObjects:          []runtime.Object{serviceAccountTokenSecretWithNamespaceData([]byte("custom"))},
+			ExistingServiceAccount: serviceAccount(tokenSecretReferences()),
+
+			AddedSecret:     serviceAccountTokenSecretWithNamespaceData([]byte("custom")),
+			ExpectedActions: []core.Action{
+			// no update is performed... the custom namespace is preserved
+			},
+		},
 
 		"updated secret without serviceaccount": {
 			ClientObjects: []runtime.Object{serviceAccountTokenSecret()},
@@ -422,6 +456,24 @@ func TestTokenCreation(t *testing.T) {
 				core.NewUpdateAction("secrets", api.NamespaceDefault, serviceAccountTokenSecret()),
 			},
 		},
+		"updated token secret without namespace data": {
+			ClientObjects:          []runtime.Object{serviceAccountTokenSecretWithoutNamespaceData()},
+			ExistingServiceAccount: serviceAccount(tokenSecretReferences()),
+
+			UpdatedSecret: serviceAccountTokenSecretWithoutNamespaceData(),
+			ExpectedActions: []core.Action{
+				core.NewUpdateAction("secrets", api.NamespaceDefault, serviceAccountTokenSecret()),
+			},
+		},
+		"updated token secret with custom namespace data": {
+			ClientObjects:          []runtime.Object{serviceAccountTokenSecretWithNamespaceData([]byte("custom"))},
+			ExistingServiceAccount: serviceAccount(tokenSecretReferences()),
+
+			UpdatedSecret:   serviceAccountTokenSecretWithNamespaceData([]byte("custom")),
+			ExpectedActions: []core.Action{
+			// no update is performed... the custom namespace is preserved
+			},
+		},
 
 		"deleted secret without serviceaccount": {
 			DeletedSecret:   serviceAccountTokenSecret(),

test/e2e/service_accounts.go

@@ -24,11 +24,14 @@ import (
 	apierrors "k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/wait"
+	"k8s.io/kubernetes/pkg/version"
 	"k8s.io/kubernetes/plugin/pkg/admission/serviceaccount"
 
 	. "github.com/onsi/ginkgo"
 )
 
+var serviceAccountTokenNamespaceVersion = version.MustParse("v1.2.0")
+
 var _ = Describe("ServiceAccounts", func() {
 	f := NewFramework("svcaccounts")
 
@@ -94,11 +97,28 @@ var _ = Describe("ServiceAccounts", func() {
 			},
 		}
 
+		supportsTokenNamespace, _ := serverVersionGTE(serviceAccountTokenNamespaceVersion, f.Client)
+		if supportsTokenNamespace {
+			pod.Spec.Containers = append(pod.Spec.Containers, api.Container{
+				Name:  "namespace-test",
+				Image: "gcr.io/google_containers/mounttest:0.2",
+				Args: []string{
+					fmt.Sprintf("--file_content=%s/%s", serviceaccount.DefaultAPITokenMountPath, api.ServiceAccountNamespaceKey),
+				},
+			})
+		}
+
 		f.TestContainerOutput("consume service account token", pod, 0, []string{
 			fmt.Sprintf(`content of file "%s/%s": %s`, serviceaccount.DefaultAPITokenMountPath, api.ServiceAccountTokenKey, tokenContent),
 		})
 		f.TestContainerOutput("consume service account root CA", pod, 1, []string{
 			fmt.Sprintf(`content of file "%s/%s": %s`, serviceaccount.DefaultAPITokenMountPath, api.ServiceAccountRootCAKey, rootCAContent),
 		})
+
+		if supportsTokenNamespace {
+			f.TestContainerOutput("consume service account namespace", pod, 2, []string{
+				fmt.Sprintf(`content of file "%s/%s": %s`, serviceaccount.DefaultAPITokenMountPath, api.ServiceAccountNamespaceKey, f.Namespace.Name),
+			})
+		}
 	})
 })