Add client auth plugin framework for kubectl with GCP auth plugin.

pkg/client/unversioned/clientcmd/api/types.go

@@ -94,6 +94,8 @@ type AuthInfo struct {
 	Username string `json:"username,omitempty"`
 	// Password is the password for basic authentication to the kubernetes cluster.
 	Password string `json:"password,omitempty"`
+	// AuthProvider specifies a custom authentication plugin for the kubernetes cluster.
+	AuthProvider *AuthProviderConfig `json:"auth-provider,omitempty"`
 	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
 	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
 }
@@ -112,6 +114,11 @@ type Context struct {
 	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
 }
 
+// AuthProviderConfig holds the configuration for a specified auth provider.
+type AuthProviderConfig struct {
+	Name string `json:"name"`
+}
+
 // NewConfig is a convenience function that returns a new Config object with non-nil maps
 func NewConfig() *Config {
 	return &Config{

pkg/client/unversioned/clientcmd/api/types_test.go

@@ -58,14 +58,17 @@ func Example_ofOptionsConfig() {
 	defaultConfig.AuthInfos["red-mage-via-token"] = &AuthInfo{
 		Token: "my-secret-token",
 	}
+	defaultConfig.AuthInfos["black-mage-via-auth-provider"] = &AuthInfo{
+		AuthProvider: &AuthProviderConfig{Name: "gcp"},
+	}
 	defaultConfig.Contexts["bravo-as-black-mage"] = &Context{
 		Cluster:   "bravo",
-		AuthInfo:  "black-mage-via-file",
+		AuthInfo:  "black-mage-via-auth-provider",
 		Namespace: "yankee",
 	}
 	defaultConfig.Contexts["alfa-as-black-mage"] = &Context{
 		Cluster:   "alfa",
-		AuthInfo:  "black-mage-via-file",
+		AuthInfo:  "black-mage-via-auth-provider",
 		Namespace: "zulu",
 	}
 	defaultConfig.Contexts["alfa-as-white-mage"] = &Context{
@@ -95,7 +98,7 @@ func Example_ofOptionsConfig() {
 	//     LocationOfOrigin: ""
 	//     cluster: alfa
 	//     namespace: zulu
-	//     user: black-mage-via-file
+	//     user: black-mage-via-auth-provider
 	//   alfa-as-white-mage:
 	//     LocationOfOrigin: ""
 	//     cluster: alfa
@@ -104,11 +107,15 @@ func Example_ofOptionsConfig() {
 	//     LocationOfOrigin: ""
 	//     cluster: bravo
 	//     namespace: yankee
-	//     user: black-mage-via-file
+	//     user: black-mage-via-auth-provider
 	// current-context: alfa-as-white-mage
 	// preferences:
 	//   colors: true
 	// users:
+	//   black-mage-via-auth-provider:
+	//     LocationOfOrigin: ""
+	//     auth-provider:
+	//       name: gcp
 	//   red-mage-via-token:
 	//     LocationOfOrigin: ""
 	//     token: my-secret-token

pkg/client/unversioned/clientcmd/api/v1/types.go

@@ -88,6 +88,8 @@ type AuthInfo struct {
 	Username string `json:"username,omitempty"`
 	// Password is the password for basic authentication to the kubernetes cluster.
 	Password string `json:"password,omitempty"`
+	// AuthProvider specifies a custom authentication plugin for the kubernetes cluster.
+	AuthProvider *AuthProviderConfig `json:"auth-provider,omitempty"`
 	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
 	Extensions []NamedExtension `json:"extensions,omitempty"`
 }
@@ -135,3 +137,8 @@ type NamedExtension struct {
 	// Extension holds the extension information
 	Extension runtime.RawExtension `json:"extension"`
 }
+
+// AuthProviderConfig holds the configuration for a specified auth provider.
+type AuthProviderConfig struct {
+	Name string `json:"name"`
+}

pkg/client/unversioned/clientcmd/client_config.go

@@ -172,6 +172,9 @@ func getUserIdentificationPartialConfig(configAuthInfo clientcmdapi.AuthInfo, fa
 		mergedConfig.Username = configAuthInfo.Username
 		mergedConfig.Password = configAuthInfo.Password
 	}
+	if configAuthInfo.AuthProvider != nil {
+		mergedConfig.AuthProvider = configAuthInfo.AuthProvider
+	}
 
 	// if there still isn't enough information to authenticate the user, try prompting
 	if !canIdentifyUser(*mergedConfig) && (fallbackReader != nil) {
@@ -212,8 +215,8 @@ func makeServerIdentificationConfig(info clientauth.Info) restclient.Config {
 func canIdentifyUser(config restclient.Config) bool {
 	return len(config.Username) > 0 ||
 		(len(config.CertFile) > 0 || len(config.CertData) > 0) ||
-		len(config.BearerToken) > 0
-
+		len(config.BearerToken) > 0 ||
+		config.AuthProvider != nil
 }
 
 // Namespace implements KubeConfig

pkg/client/unversioned/helper.go

@@ -29,6 +29,8 @@ import (
 	"k8s.io/kubernetes/pkg/client/typed/discovery"
 	"k8s.io/kubernetes/pkg/util/sets"
 	"k8s.io/kubernetes/pkg/version"
+	// Import solely to initialize client auth plugins.
+	_ "k8s.io/kubernetes/plugin/pkg/client/auth"
 )
 
 const (