Merge pull request #119398 from IvoGoman/feat/clientconfig-override-raw

k8s.io/client-go: add ClientConfig option to override raw config

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
@@ -129,6 +136,40 @@ func (config *DirectClientConfig) RawConfig() (clientcmdapi.Config, error) {
 	return config.config, nil
 }
 
+// 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 := config.config.DeepCopy()
+
+	// set the AuthInfo merged with overrides in the merged config
+	mergedAuthInfo, err := config.getAuthInfo()
+	if err != nil {
+		return clientcmdapi.Config{}, err
+	}
+	mergedAuthInfoName, _ := config.getAuthInfoName()
+	merged.AuthInfos[mergedAuthInfoName] = &mergedAuthInfo
+
+	// set the Context merged with overrides in the merged config
+	mergedContext, err := config.getContext()
+	if err != nil {
+		return clientcmdapi.Config{}, err
+	}
+	mergedContextName, _ := config.getContextName()
+	merged.Contexts[mergedContextName] = &mergedContext
+	merged.CurrentContext = mergedContextName
+
+	// set the Cluster merged with overrides in the merged config
+	configClusterInfo, err := config.getCluster()
+	if err != nil {
+		return clientcmdapi.Config{}, err
+	}
+	configClusterName, _ := config.getClusterName()
+	merged.Clusters[configClusterName] = &configClusterInfo
+	return *merged, nil
+}
+
 // ClientConfig implements ClientConfig
 func (config *DirectClientConfig) ClientConfig() (*restclient.Config, error) {
 	// check that getAuthInfo, getContext, and getCluster do not return an error.

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

@@ -1013,3 +1013,68 @@ func TestCleanANSIEscapeCodes(t *testing.T) {
 		})
 	}
 }
+
+func TestMergeRawConfigDoOverride(t *testing.T) {
+	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: modifiedServer,
+		},
+		Context: clientcmdapi.Context{
+			Namespace: "foobar",
+			Cluster:   "modify",
+			AuthInfo:  "modify",
+		},
+		AuthInfo: clientcmdapi.AuthInfo{
+			Token: modifiedToken,
+		},
+		CurrentContext: "modify",
+	}
+
+	cut := NewDefaultClientConfig(*config, overrides)
+	act, err := cut.MergedRawConfig()
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	// 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)
+	}
+
+	// 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)
+	}
+}