add --as-group option to cli

The usecase of this change:
When a super user grant some RBAC permissions to a group, he can use
--as-group to test whether the group get the permissions.
Note that now we support as-groups, as-user-extra in kubeconfig file
after this change.

hack/make-rules/test-cmd-util.sh

@@ -28,6 +28,7 @@ KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
 ETCD_HOST=${ETCD_HOST:-127.0.0.1}
 ETCD_PORT=${ETCD_PORT:-2379}
 API_PORT=${API_PORT:-8080}
+SECURE_API_PORT=${SECURE_API_PORT:-6443}
 API_HOST=${API_HOST:-127.0.0.1}
 KUBELET_PORT=${KUBELET_PORT:-10250}
 KUBELET_HEALTHZ_PORT=${KUBELET_HEALTHZ_PORT:-10248}
@@ -2855,8 +2856,14 @@ runTests() {
   kube_flags=(
     -s "http://127.0.0.1:${API_PORT}"
   )
+
+  kube_flags_with_token=(
+    -s "https://127.0.0.1:${SECURE_API_PORT}" --token=admin/system:masters --insecure-skip-tls-verify=true
+  )
+
   if [[ -z "${ALLOW_SKEW:-}" ]]; then
     kube_flags+=("--match-server-version")
+    kube_flags_with_token+=("--match-server-version")
   fi
   if kube::test::if_supports_resource "${nodes}" ; then
     [ "$(kubectl get nodes -o go-template='{{ .apiVersion }}' "${kube_flags[@]}")" == "v1" ]
@@ -3762,5 +3769,25 @@ __EOF__
   output_message=$(! KUBECTL_PLUGINS_PATH=test/fixtures/pkg/kubectl/plugins/ kubectl plugin error 2>&1)
   kube::test::if_has_string "${output_message}" 'error: exit status 1'
 
+  #################
+  # Impersonation #
+  #################
+  output_message=$(! kubectl get pods "${kube_flags_with_token[@]}" --as-group=foo 2>&1)
+  kube::test::if_has_string "${output_message}" 'without impersonating a user'
+
+  if kube::test::if_supports_resource "${csr}" ; then
+    # --as
+    kubectl create -f hack/testdata/csr.yml "${kube_flags_with_token[@]}" --as=user1
+    kube::test::get_object_assert 'csr/foo' '{{.spec.username}}' 'user1'
+    kube::test::get_object_assert 'csr/foo' '{{range .spec.groups}}{{.}}{{end}}' 'system:authenticated'
+    kubectl delete -f hack/testdata/csr.yml "${kube_flags_with_token[@]}"
+
+    # --as-group
+    kubectl create -f hack/testdata/csr.yml "${kube_flags_with_token[@]}" --as=user1 --as-group=group2 --as-group=group1 --as-group=,,,chameleon
+    kube::test::get_object_assert 'csr/foo' '{{len .spec.groups}}' '3'
+    kube::test::get_object_assert 'csr/foo' '{{range .spec.groups}}{{.}} {{end}}' 'group2 group1 ,,,chameleon '
+    kubectl delete -f hack/testdata/csr.yml "${kube_flags_with_token[@]}"
+  fi
+
   kube::test::clear_all
 }

hack/make-rules/test-cmd.sh

@@ -44,6 +44,7 @@ function run_kube_apiserver() {
     --public-address-override="127.0.0.1" \
     --port="${API_PORT}" \
     --authorization-mode="${AUTHORIZATION_MODE}" \
+    --secure-port="${SECURE_API_PORT}" \
     --admission-control="${ADMISSION_CONTROL}" \
     --etcd-servers="http://${ETCD_HOST}:${ETCD_PORT}" \
     --public-address-override="127.0.0.1" \
@@ -51,7 +52,8 @@ function run_kube_apiserver() {
     --runtime-config=api/v1 \
     --storage-media-type="${KUBE_TEST_API_STORAGE_TYPE-}" \
     --cert-dir="${TMPDIR:-/tmp/}" \
-    --service-cluster-ip-range="10.0.0.0/24" 1>&2 &
+    --service-cluster-ip-range="10.0.0.0/24" \
+    --insecure-allow-any-token 1>&2 &
   APISERVER_PID=$!
 
   kube::util::wait_for_url "http://127.0.0.1:${API_PORT}/healthz" "apiserver"

hack/make-rules/test-federation-cmd.sh

@@ -38,10 +38,12 @@ function run_federation_apiserver() {
 
   "${KUBE_OUTPUT_HOSTBIN}/federation-apiserver" \
     --insecure-port="${API_PORT}" \
+    --secure-port="${SECURE_API_PORT}" \
     --admission-control="${ADMISSION_CONTROL}" \
     --etcd-servers="http://${ETCD_HOST}:${ETCD_PORT}" \
     --storage-media-type="${KUBE_TEST_API_STORAGE_TYPE-}" \
-    --cert-dir="${TMPDIR:-/tmp/}" 1>&2 &
+    --cert-dir="${TMPDIR:-/tmp/}" \
+    --insecure-allow-any-token 1>&2 &
   APISERVER_PID=$!
 
   kube::util::wait_for_url "http://127.0.0.1:${API_PORT}/healthz" "apiserver"

staging/src/k8s.io/client-go/tools/clientcmd/api/types.go

@@ -109,6 +109,12 @@ type AuthInfo struct {
 	// Impersonate is the username to act-as.
 	// +optional
 	Impersonate string `json:"act-as,omitempty"`
+	// ImpersonateGroups is the groups to imperonate.
+	// +optional
+	ImpersonateGroups []string `json:"act-as-groups,omitempty"`
+	// ImpersonateUserExtra contains additional information for impersonated user.
+	// +optional
+	ImpersonateUserExtra map[string][]string `json:"act-as-user-extra,omitempty"`
 	// Username is the username for basic authentication to the kubernetes cluster.
 	// +optional
 	Username string `json:"username,omitempty"`
@@ -172,7 +178,10 @@ func NewCluster() *Cluster {
 // NewAuthInfo is a convenience function that returns a new AuthInfo
 // object with non-nil maps
 func NewAuthInfo() *AuthInfo {
-	return &AuthInfo{Extensions: make(map[string]runtime.Object)}
+	return &AuthInfo{
+		Extensions:           make(map[string]runtime.Object),
+		ImpersonateUserExtra: make(map[string][]string),
+	}
 }
 
 // NewPreferences is a convenience function that returns a new

staging/src/k8s.io/client-go/tools/clientcmd/api/v1/types.go

@@ -103,6 +103,12 @@ type AuthInfo struct {
 	// Impersonate is the username to imperonate.  The name matches the flag.
 	// +optional
 	Impersonate string `json:"as,omitempty"`
+	// ImpersonateGroups is the groups to imperonate.
+	// +optional
+	ImpersonateGroups []string `json:"as-groups,omitempty"`
+	// ImpersonateUserExtra contains additional information for impersonated user.
+	// +optional
+	ImpersonateUserExtra map[string][]string `json:"as-user-extra,omitempty"`
 	// Username is the username for basic authentication to the kubernetes cluster.
 	// +optional
 	Username string `json:"username,omitempty"`

staging/src/k8s.io/client-go/tools/clientcmd/client_config.go

@@ -146,7 +146,11 @@ func (config *DirectClientConfig) ClientConfig() (*restclient.Config, error) {
 		clientConfig.Host = u.String()
 	}
 	if len(configAuthInfo.Impersonate) > 0 {
-		clientConfig.Impersonate = restclient.ImpersonationConfig{UserName: configAuthInfo.Impersonate}
+		clientConfig.Impersonate = restclient.ImpersonationConfig{
+			UserName: configAuthInfo.Impersonate,
+			Groups:   configAuthInfo.ImpersonateGroups,
+			Extra:    configAuthInfo.ImpersonateUserExtra,
+		}
 	}
 
 	// only try to read the auth information if we are secure
@@ -217,7 +221,11 @@ func (config *DirectClientConfig) getUserIdentificationPartialConfig(configAuthI
 		mergedConfig.BearerToken = string(tokenBytes)
 	}
 	if len(configAuthInfo.Impersonate) > 0 {
-		mergedConfig.Impersonate = restclient.ImpersonationConfig{UserName: configAuthInfo.Impersonate}
+		mergedConfig.Impersonate = restclient.ImpersonationConfig{
+			UserName: configAuthInfo.Impersonate,
+			Groups:   configAuthInfo.ImpersonateGroups,
+			Extra:    configAuthInfo.ImpersonateUserExtra,
+		}
 	}
 	if len(configAuthInfo.ClientCertificate) > 0 || len(configAuthInfo.ClientCertificateData) > 0 {
 		mergedConfig.CertFile = configAuthInfo.ClientCertificate

staging/src/k8s.io/client-go/tools/clientcmd/overrides.go

@@ -52,6 +52,7 @@ type AuthOverrideFlags struct {
 	ClientKey         FlagInfo
 	Token             FlagInfo
 	Impersonate       FlagInfo
+	ImpersonateGroups FlagInfo
 	Username          FlagInfo
 	Password          FlagInfo
 }
@@ -100,6 +101,19 @@ func (f FlagInfo) BindStringFlag(flags *pflag.FlagSet, target *string) FlagInfo
 	return f
 }
 
+// BindStringSliceFlag binds the flag based on the provided info.  If LongName == "", nothing is registered
+func (f FlagInfo) BindStringArrayFlag(flags *pflag.FlagSet, target *[]string) FlagInfo {
+	// you can't register a flag without a long name
+	if len(f.LongName) > 0 {
+		sliceVal := []string{}
+		if len(f.Default) > 0 {
+			sliceVal = []string{f.Default}
+		}
+		flags.StringArrayVarP(target, f.LongName, f.ShortName, sliceVal, f.Description)
+	}
+	return f
+}
+
 // BindBoolFlag binds the flag based on the provided info.  If LongName == "", nothing is registered
 func (f FlagInfo) BindBoolFlag(flags *pflag.FlagSet, target *bool) FlagInfo {
 	// you can't register a flag without a long name
@@ -116,22 +130,23 @@ func (f FlagInfo) BindBoolFlag(flags *pflag.FlagSet, target *bool) FlagInfo {
 }
 
 const (
-	FlagClusterName  = "cluster"
-	FlagAuthInfoName = "user"
-	FlagContext      = "context"
-	FlagNamespace    = "namespace"
-	FlagAPIServer    = "server"
-	FlagAPIVersion   = "api-version"
-	FlagInsecure     = "insecure-skip-tls-verify"
-	FlagCertFile     = "client-certificate"
-	FlagKeyFile      = "client-key"
-	FlagCAFile       = "certificate-authority"
-	FlagEmbedCerts   = "embed-certs"
-	FlagBearerToken  = "token"
-	FlagImpersonate  = "as"
-	FlagUsername     = "username"
-	FlagPassword     = "password"
-	FlagTimeout      = "request-timeout"
+	FlagClusterName      = "cluster"
+	FlagAuthInfoName     = "user"
+	FlagContext          = "context"
+	FlagNamespace        = "namespace"
+	FlagAPIServer        = "server"
+	FlagAPIVersion       = "api-version"
+	FlagInsecure         = "insecure-skip-tls-verify"
+	FlagCertFile         = "client-certificate"
+	FlagKeyFile          = "client-key"
+	FlagCAFile           = "certificate-authority"
+	FlagEmbedCerts       = "embed-certs"
+	FlagBearerToken      = "token"
+	FlagImpersonate      = "as"
+	FlagImpersonateGroup = "as-group"
+	FlagUsername         = "username"
+	FlagPassword         = "password"
+	FlagTimeout          = "request-timeout"
 )
 
 // RecommendedConfigOverrideFlags is a convenience method to return recommended flag names prefixed with a string of your choosing
@@ -153,6 +168,7 @@ func RecommendedAuthOverrideFlags(prefix string) AuthOverrideFlags {
 		ClientKey:         FlagInfo{prefix + FlagKeyFile, "", "", "Path to a client key file for TLS"},
 		Token:             FlagInfo{prefix + FlagBearerToken, "", "", "Bearer token for authentication to the API server"},
 		Impersonate:       FlagInfo{prefix + FlagImpersonate, "", "", "Username to impersonate for the operation"},
+		ImpersonateGroups: FlagInfo{prefix + FlagImpersonateGroup, "", "", "Group to impersonate for the operation, this flag can be repeated to specify multiple groups."},
 		Username:          FlagInfo{prefix + FlagUsername, "", "", "Username for basic authentication to the API server"},
 		Password:          FlagInfo{prefix + FlagPassword, "", "", "Password for basic authentication to the API server"},
 	}
@@ -192,6 +208,7 @@ func BindAuthInfoFlags(authInfo *clientcmdapi.AuthInfo, flags *pflag.FlagSet, fl
 	flagNames.ClientKey.BindStringFlag(flags, &authInfo.ClientKey).AddSecretAnnotation(flags)
 	flagNames.Token.BindStringFlag(flags, &authInfo.Token).AddSecretAnnotation(flags)
 	flagNames.Impersonate.BindStringFlag(flags, &authInfo.Impersonate).AddSecretAnnotation(flags)
+	flagNames.ImpersonateGroups.BindStringArrayFlag(flags, &authInfo.ImpersonateGroups).AddSecretAnnotation(flags)
 	flagNames.Username.BindStringFlag(flags, &authInfo.Username).AddSecretAnnotation(flags)
 	flagNames.Password.BindStringFlag(flags, &authInfo.Password).AddSecretAnnotation(flags)
 }

staging/src/k8s.io/client-go/tools/clientcmd/validation.go

@@ -242,6 +242,10 @@ func validateAuthInfo(authInfoName string, authInfo clientcmdapi.AuthInfo) []err
 		validationErrors = append(validationErrors, fmt.Errorf("more than one authentication method found for %v; found %v, only one is allowed", authInfoName, methods))
 	}
 
+	// ImpersonateGroups or ImpersonateUserExtra should be requested with a user
+	if (len(authInfo.ImpersonateGroups) > 0 || len(authInfo.ImpersonateUserExtra) > 0) && (len(authInfo.Impersonate) == 0) {
+		validationErrors = append(validationErrors, fmt.Errorf("requesting groups or user-extra for %v without impersonating a user", authInfoName))
+	}
 	return validationErrors
 }