k8s.io/client-go: add OverridingClientConfig overriding RawConfig

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

@@ -72,6 +72,13 @@ type ClientConfig interface {
 	ConfigAccess() ConfigAccess
 }
 
+// OverridingClientConfig is used to enable overrriding the raw KubeConfig
+type OverridingClientConfig interface {
+	ClientConfig
+	// MergedRawConfig return the RawConfig merged with all overrides.
+	MergedRawConfig() (clientcmdapi.Config, error)
+}
+
 type PersistAuthProviderConfigForUser func(user string) restclient.AuthProviderConfigPersister
 
 type promptedCredentials struct {
@@ -91,22 +98,22 @@ type DirectClientConfig struct {
 }
 
 // NewDefaultClientConfig creates a DirectClientConfig using the config.CurrentContext as the context name
-func NewDefaultClientConfig(config clientcmdapi.Config, overrides *ConfigOverrides) ClientConfig {
+func NewDefaultClientConfig(config clientcmdapi.Config, overrides *ConfigOverrides) OverridingClientConfig {
 	return &DirectClientConfig{config, config.CurrentContext, overrides, nil, NewDefaultClientConfigLoadingRules(), promptedCredentials{}}
 }
 
 // NewNonInteractiveClientConfig creates a DirectClientConfig using the passed context name and does not have a fallback reader for auth information
-func NewNonInteractiveClientConfig(config clientcmdapi.Config, contextName string, overrides *ConfigOverrides, configAccess ConfigAccess) ClientConfig {
+func NewNonInteractiveClientConfig(config clientcmdapi.Config, contextName string, overrides *ConfigOverrides, configAccess ConfigAccess) OverridingClientConfig {
 	return &DirectClientConfig{config, contextName, overrides, nil, configAccess, promptedCredentials{}}
 }
 
 // NewInteractiveClientConfig creates a DirectClientConfig using the passed context name and a reader in case auth information is not provided via files or flags
-func NewInteractiveClientConfig(config clientcmdapi.Config, contextName string, overrides *ConfigOverrides, fallbackReader io.Reader, configAccess ConfigAccess) ClientConfig {
+func NewInteractiveClientConfig(config clientcmdapi.Config, contextName string, overrides *ConfigOverrides, fallbackReader io.Reader, configAccess ConfigAccess) OverridingClientConfig {
 	return &DirectClientConfig{config, contextName, overrides, fallbackReader, configAccess, promptedCredentials{}}
 }
 
 // NewClientConfigFromBytes takes your kubeconfig and gives you back a ClientConfig
-func NewClientConfigFromBytes(configBytes []byte) (ClientConfig, error) {
+func NewClientConfigFromBytes(configBytes []byte) (OverridingClientConfig, error) {
 	config, err := Load(configBytes)
 	if err != nil {
 		return nil, err
@@ -115,19 +122,6 @@ func NewClientConfigFromBytes(configBytes []byte) (ClientConfig, error) {
 	return &DirectClientConfig{*config, "", &ConfigOverrides{}, nil, nil, promptedCredentials{}}, nil
 }
 
-// NewClientConfigWithMergedRawConfig acts like a NewDefaultClientConfig but merges the RawConfig with the overrides
-func NewClientConfigWithMergedRawConfig(config clientcmdapi.Config, overrides *ConfigOverrides) (ClientConfig, error) {
-	clientCfg := &DirectClientConfig{config, config.CurrentContext, overrides, nil, NewDefaultClientConfigLoadingRules(), promptedCredentials{}}
-
-	mergedRawCfg, err := clientCfg.getMergedRawConfig()
-	clientCfg.config = mergedRawCfg
-	if err != nil {
-		return nil, err
-	}
-	return clientCfg, nil
-
-}
-
 // RESTConfigFromKubeConfig is a convenience method to give back a restconfig from your kubeconfig bytes.
 // For programmatic access, this is what you want 80% of the time
 func RESTConfigFromKubeConfig(configBytes []byte) (*restclient.Config, error) {
@@ -142,12 +136,12 @@ func (config *DirectClientConfig) RawConfig() (clientcmdapi.Config, error) {
 	return config.config, nil
 }
 
-// getMergedRawConfig returns the raw kube config merged with the overrides
-func (config *DirectClientConfig) getMergedRawConfig() (clientcmdapi.Config, error) {
+// MergedRawConfig returns the raw kube config merged with the overrides
+func (config *DirectClientConfig) MergedRawConfig() (clientcmdapi.Config, error) {
 	if err := config.ConfirmUsable(); err != nil {
 		return clientcmdapi.Config{}, err
 	}
-	merged := clientcmdapi.NewConfig()
+	merged := config.config.DeepCopy()
 
 	// set the AuthInfo merged with overrides in the merged config
 	mergedAuthInfo, err := config.getAuthInfo()

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

@@ -1015,70 +1015,66 @@ func TestCleanANSIEscapeCodes(t *testing.T) {
 }
 
 func TestMergeRawConfigDoOverride(t *testing.T) {
-	cfg := createValidTestConfig()
+	const (
+		server         = "https://anything.com:8080"
+		token          = "the-token"
+		modifiedServer = "http://localhost:8081"
+		modifiedToken  = "modified-token"
+	)
+	config := createValidTestConfig()
 
+	// add another context which to modify with overrides
+	config.Clusters["modify"] = &clientcmdapi.Cluster{
+		Server: server,
+	}
+	config.AuthInfos["modify"] = &clientcmdapi.AuthInfo{
+		Token: token,
+	}
+	config.Contexts["modify"] = &clientcmdapi.Context{
+		Cluster:   "modify",
+		AuthInfo:  "modify",
+		Namespace: "modify",
+	}
+
+	// create overrides for the modify context
 	overrides := &ConfigOverrides{
 		ClusterInfo: clientcmdapi.Cluster{
-			Server: "http://localhost:8081",
+			Server: modifiedServer,
 		},
 		Context: clientcmdapi.Context{
 			Namespace: "foobar",
-			Cluster:   "clean",
-			AuthInfo:  "clean",
+			Cluster:   "modify",
+			AuthInfo:  "modify",
 		},
 		AuthInfo: clientcmdapi.AuthInfo{
-			Token: "modified-token",
+			Token: modifiedToken,
 		},
-		CurrentContext: "clean",
+		CurrentContext: "modify",
 	}
 
-	cut, err := NewClientConfigWithMergedRawConfig(*cfg, overrides)
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-	act, err := cut.RawConfig()
+	cut := NewDefaultClientConfig(*config, overrides)
+	act, err := cut.MergedRawConfig()
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
 
-	if act.Clusters["clean"].Server != "http://localhost:8081" {
-		t.Errorf("Expected server %v, got %v", "http://localhost:8081", act.Clusters["clean"].Server)
+	// ensure overrides were applied to "modify"
+	actContext := act.CurrentContext
+	if actContext != "modify" {
+		t.Errorf("Expected context %v, got %v", "modify", actContext)
+	}
+	if act.Clusters[actContext].Server != "http://localhost:8081" {
+		t.Errorf("Expected server %v, got %v", "http://localhost:8081", act.Clusters[actContext].Server)
+	}
+	if act.Contexts[actContext].Namespace != "foobar" {
+		t.Errorf("Expected namespace %v, got %v", "foobar", act.Contexts[actContext].Namespace)
 	}
 
-	if act.Contexts["clean"].Namespace != "foobar" {
-		t.Errorf("Expected namespace %v, got %v", "foobar", act.Contexts["clean"].Namespace)
-	}
-}
-
-func TestMergeRawConfigDoNotOverride(t *testing.T) {
-	cfg := createValidTestConfig()
-
-	overrides := &ConfigOverrides{
-		ClusterInfo: clientcmdapi.Cluster{
-			Server: "http://localhost:8081",
-		},
-		Context: clientcmdapi.Context{
-			Namespace: "foobar",
-			Cluster:   "clean",
-			AuthInfo:  "clean",
-		},
-		AuthInfo: clientcmdapi.AuthInfo{
-			Token: "modified-token",
-		},
-		CurrentContext: "clean",
-	}
-
-	cut := NewDefaultClientConfig(*cfg, overrides)
-	act, err := cut.RawConfig()
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-
-	if act.Clusters["clean"].Server != cfg.Clusters["clean"].Server {
-		t.Errorf("Expected server %v, got %v", cfg.Clusters["clean"].Server, act.Clusters["clean"].Server)
-	}
-
-	if act.Contexts["clean"].Namespace != cfg.Contexts["clean"].Namespace {
-		t.Errorf("Expected namespace %v, got %v", cfg.Contexts["clean"].Namespace, act.Contexts["clean"].Namespace)
+	// ensure context "clean" was not touched
+	if act.Clusters["clean"].Server != config.Clusters["clean"].Server {
+		t.Errorf("Expected server %v, got %v", config.Clusters["clean"].Server, act.Clusters["clean"].Server)
+	}
+	if act.Contexts["clean"].Namespace != config.Contexts["clean"].Namespace {
+		t.Errorf("Expected namespace %v, got %v", config.Contexts["clean"].Namespace, act.Contexts["clean"].Namespace)
 	}
 }