Let .kubeconfig populate ca/cert/key data, and basic-auth username/password in client configs

pkg/client/clientcmd/api/types.go

@@ -57,6 +57,8 @@ type Cluster struct {
 	InsecureSkipTLSVerify bool `json:"insecure-skip-tls-verify,omitempty"`
 	// CertificateAuthority is the path to a cert file for the certificate authority.
 	CertificateAuthority string `json:"certificate-authority,omitempty"`
+	// CertificateAuthorityData contains PEM-encoded certificate authority certificates. Overrides CertificateAuthority
+	CertificateAuthorityData []byte `json:"certificate-authority-data,omitempty"`
 	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
 	Extensions map[string]runtime.EmbeddedObject `json:"extensions,omitempty"`
 }
@@ -67,10 +69,18 @@ type AuthInfo struct {
 	AuthPath string `json:"auth-path,omitempty"`
 	// ClientCertificate is the path to a client cert file for TLS.
 	ClientCertificate string `json:"client-certificate,omitempty"`
+	// ClientCertificateData contains PEM-encoded data from a client cert file for TLS. Overrides ClientCertificate
+	ClientCertificateData []byte `json:"client-certificate-data,omitempty"`
 	// ClientKey is the path to a client key file for TLS.
 	ClientKey string `json:"client-key,omitempty"`
+	// ClientKeyData contains PEM-encoded data from a client key file for TLS. Overrides ClientKey
+	ClientKeyData []byte `json:"client-key-data,omitempty"`
 	// Token is the bearer token for authentication to the kubernetes cluster.
 	Token string `json:"token,omitempty"`
+	// Username is the username for basic authentication to the kubernetes cluster.
+	Username string `json:"username,omitempty"`
+	// Password is the password for basic authentication to the kubernetes cluster.
+	Password string `json:"password,omitempty"`
 	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
 	Extensions map[string]runtime.EmbeddedObject `json:"extensions,omitempty"`
 }

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

@@ -57,6 +57,8 @@ type Cluster struct {
 	InsecureSkipTLSVerify bool `json:"insecure-skip-tls-verify,omitempty"`
 	// CertificateAuthority is the path to a cert file for the certificate authority.
 	CertificateAuthority string `json:"certificate-authority,omitempty"`
+	// CertificateAuthorityData contains PEM-encoded certificate authority certificates. Overrides CertificateAuthority
+	CertificateAuthorityData []byte `json:"certificate-authority-data,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"`
 }
@@ -67,10 +69,18 @@ type AuthInfo struct {
 	AuthPath string `json:"auth-path,omitempty"`
 	// ClientCertificate is the path to a client cert file for TLS.
 	ClientCertificate string `json:"client-certificate,omitempty"`
+	// ClientCertificateData contains PEM-encoded data from a client cert file for TLS. Overrides ClientCertificate
+	ClientCertificateData []byte `json:"client-certificate-data,omitempty"`
 	// ClientKey is the path to a client key file for TLS.
 	ClientKey string `json:"client-key,omitempty"`
+	// ClientKeyData contains PEM-encoded data from a client key file for TLS. Overrides ClientKey
+	ClientKeyData []byte `json:"client-key-data,omitempty"`
 	// Token is the bearer token for authentication to the kubernetes cluster.
 	Token string `json:"token,omitempty"`
+	// Username is the username for basic authentication to the kubernetes cluster.
+	Username string `json:"username,omitempty"`
+	// Password is the password for basic authentication to the kubernetes cluster.
+	Password string `json:"password,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"`
 }

pkg/client/clientcmd/client_config.go

@@ -140,6 +140,7 @@ func getServerIdentificationPartialConfig(configAuthInfo clientcmdapi.AuthInfo,
 	// configClusterInfo holds the information identify the server provided by .kubeconfig
 	configClientConfig := &client.Config{}
 	configClientConfig.CAFile = configClusterInfo.CertificateAuthority
+	configClientConfig.CAData = configClusterInfo.CertificateAuthorityData
 	configClientConfig.Insecure = configClusterInfo.InsecureSkipTLSVerify
 	mergo.Merge(mergedConfig, configClientConfig)
 
@@ -169,9 +170,15 @@ func getUserIdentificationPartialConfig(configAuthInfo clientcmdapi.AuthInfo, fa
 	if len(configAuthInfo.Token) > 0 {
 		mergedConfig.BearerToken = configAuthInfo.Token
 	}
-	if len(configAuthInfo.ClientCertificate) > 0 {
+	if len(configAuthInfo.ClientCertificate) > 0 || len(configAuthInfo.ClientCertificateData) > 0 {
 		mergedConfig.CertFile = configAuthInfo.ClientCertificate
+		mergedConfig.CertData = configAuthInfo.ClientCertificateData
 		mergedConfig.KeyFile = configAuthInfo.ClientKey
+		mergedConfig.KeyData = configAuthInfo.ClientKeyData
+	}
+	if len(configAuthInfo.Username) > 0 || len(configAuthInfo.Password) > 0 {
+		mergedConfig.Username = configAuthInfo.Username
+		mergedConfig.Password = configAuthInfo.Password
 	}
 
 	// if there isn't sufficient information to authenticate the user to the server, merge in ~/.kubernetes_auth.
@@ -228,7 +235,7 @@ func makeServerIdentificationConfig(info clientauth.Info) client.Config {
 
 func canIdentifyUser(config client.Config) bool {
 	return len(config.Username) > 0 ||
-		len(config.CertFile) > 0 ||
+		(len(config.CertFile) > 0 || len(config.CertData) > 0) ||
 		len(config.BearerToken) > 0
 
 }

pkg/client/clientcmd/client_config_test.go

@@ -66,6 +66,71 @@ func TestMergeContext(t *testing.T) {
 	matchStringArg(namespace, actual, t)
 }
 
+func TestCertificateData(t *testing.T) {
+	caData := []byte("ca-data")
+	certData := []byte("cert-data")
+	keyData := []byte("key-data")
+
+	config := clientcmdapi.NewConfig()
+	config.Clusters["clean"] = clientcmdapi.Cluster{
+		Server:                   "https://localhost:8443",
+		APIVersion:               latest.Version,
+		CertificateAuthorityData: caData,
+	}
+	config.AuthInfos["clean"] = clientcmdapi.AuthInfo{
+		ClientCertificateData: certData,
+		ClientKeyData:         keyData,
+	}
+	config.Contexts["clean"] = clientcmdapi.Context{
+		Cluster:  "clean",
+		AuthInfo: "clean",
+	}
+	config.CurrentContext = "clean"
+
+	clientBuilder := NewNonInteractiveClientConfig(*config, "clean", &ConfigOverrides{})
+
+	clientConfig, err := clientBuilder.ClientConfig()
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	// Make sure cert data gets into config (will override file paths)
+	matchByteArg(caData, clientConfig.TLSClientConfig.CAData, t)
+	matchByteArg(certData, clientConfig.TLSClientConfig.CertData, t)
+	matchByteArg(keyData, clientConfig.TLSClientConfig.KeyData, t)
+}
+
+func TestBasicAuthData(t *testing.T) {
+	username := "myuser"
+	password := "mypass"
+
+	config := clientcmdapi.NewConfig()
+	config.Clusters["clean"] = clientcmdapi.Cluster{
+		Server:     "https://localhost:8443",
+		APIVersion: latest.Version,
+	}
+	config.AuthInfos["clean"] = clientcmdapi.AuthInfo{
+		Username: username,
+		Password: password,
+	}
+	config.Contexts["clean"] = clientcmdapi.Context{
+		Cluster:  "clean",
+		AuthInfo: "clean",
+	}
+	config.CurrentContext = "clean"
+
+	clientBuilder := NewNonInteractiveClientConfig(*config, "clean", &ConfigOverrides{})
+
+	clientConfig, err := clientBuilder.ClientConfig()
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	// Make sure basic auth data gets into config
+	matchStringArg(username, clientConfig.Username, t)
+	matchStringArg(password, clientConfig.Password, t)
+}
+
 func TestCreateClean(t *testing.T) {
 	config := createValidTestConfig()
 	clientBuilder := NewNonInteractiveClientConfig(*config, "clean", &ConfigOverrides{})
@@ -123,3 +188,9 @@ func matchStringArg(expected, got string, t *testing.T) {
 		t.Errorf("Expected %v, got %v", expected, got)
 	}
 }
+
+func matchByteArg(expected, got []byte, t *testing.T) {
+	if !reflect.DeepEqual(expected, got) {
+		t.Errorf("Expected %v, got %v", expected, got)
+	}
+}

pkg/client/clientcmd/loader.go

@@ -153,36 +153,46 @@ func resolveLocalPath(startingDir, path string) string {
 
 // LoadFromFile takes a filename and deserializes the contents into Config object
 func LoadFromFile(filename string) (*clientcmdapi.Config, error) {
-	config := &clientcmdapi.Config{}
-
 	kubeconfigBytes, err := ioutil.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}
+	return Load(kubeconfigBytes)
+}
 
-	if err := clientcmdlatest.Codec.DecodeInto(kubeconfigBytes, config); err != nil {
+// Load takes a byte slice and deserializes the contents into Config object.
+// Encapsulates deserialization without assuming the source is a file.
+func Load(data []byte) (*clientcmdapi.Config, error) {
+	config := &clientcmdapi.Config{}
+	if err := clientcmdlatest.Codec.DecodeInto(data, config); err != nil {
 		return nil, err
 	}
-
 	return config, nil
 }
 
-// WriteToFile serializes the config to yaml and writes it out to a file.  If no present, it creates the file with 0644.  If it is present
+// WriteToFile serializes the config to yaml and writes it out to a file.  If not present, it creates the file with the mode 0600.  If it is present
 // it stomps the contents
 func WriteToFile(config clientcmdapi.Config, filename string) error {
-	json, err := clientcmdlatest.Codec.Encode(&config)
+	content, err := Write(config)
 	if err != nil {
 		return err
 	}
-
-	content, err := yaml.JSONToYAML(json)
-	if err != nil {
+	if err := ioutil.WriteFile(filename, content, 0600); err != nil {
 		return err
 	}
+	return nil
+}
 
-	if err := ioutil.WriteFile(filename, content, 0644); err != nil {
-		return err
+// Write serializes the config to yaml.
+// Encapsulates serialization without assuming the destination is a file.
+func Write(config clientcmdapi.Config) ([]byte, error) {
+	json, err := clientcmdlatest.Codec.Encode(&config)
+	if err != nil {
+		return nil, err
 	}
-
-	return nil
+	content, err := yaml.JSONToYAML(json)
+	if err != nil {
+		return nil, err
+	}
+	return content, nil
 }

pkg/client/clientcmd/overrides.go

@@ -47,6 +47,8 @@ type AuthOverrideFlags struct {
 	ClientCertificate string
 	ClientKey         string
 	Token             string
+	Username          string
+	Password          string
 }
 
 // ContextOverrideFlags holds the flag names to be used for binding command line flags for Cluster objects
@@ -80,6 +82,8 @@ const (
 	FlagKeyFile      = "client-key"
 	FlagCAFile       = "certificate-authority"
 	FlagBearerToken  = "token"
+	FlagUsername     = "username"
+	FlagPassword     = "password"
 )
 
 // RecommendedAuthOverrideFlags is a convenience method to return recommended flag names prefixed with a string of your choosing
@@ -89,6 +93,8 @@ func RecommendedAuthOverrideFlags(prefix string) AuthOverrideFlags {
 		ClientCertificate: prefix + FlagCertFile,
 		ClientKey:         prefix + FlagKeyFile,
 		Token:             prefix + FlagBearerToken,
+		Username:          prefix + FlagUsername,
+		Password:          prefix + FlagPassword,
 	}
 }
 
@@ -127,6 +133,8 @@ func BindAuthInfoFlags(authInfo *clientcmdapi.AuthInfo, flags *pflag.FlagSet, fl
 	flags.StringVar(&authInfo.ClientCertificate, flagNames.ClientCertificate, "", "Path to a client key file for TLS.")
 	flags.StringVar(&authInfo.ClientKey, flagNames.ClientKey, "", "Path to a client key file for TLS.")
 	flags.StringVar(&authInfo.Token, flagNames.Token, "", "Bearer token for authentication to the API server.")
+	flags.StringVar(&authInfo.Username, flagNames.Username, "", "Username for basic authentication to the API server.")
+	flags.StringVar(&authInfo.Password, flagNames.Password, "", "Password for basic authentication to the API server.")
 }
 
 // BindClusterFlags is a convenience method to bind the specified flags to their associated variables

pkg/client/clientcmd/validation.go

@@ -109,6 +109,10 @@ func validateClusterInfo(clusterName string, clusterInfo clientcmdapi.Cluster) [
 	if len(clusterInfo.Server) == 0 {
 		validationErrors = append(validationErrors, fmt.Errorf("no server found for %v", clusterName))
 	}
+	// Make sure CA data and CA file aren't both specified
+	if len(clusterInfo.CertificateAuthority) != 0 && len(clusterInfo.CertificateAuthorityData) != 0 {
+		validationErrors = append(validationErrors, fmt.Errorf("certificate-authority-data and certificate-authority are both specified for %v. certificate-authority-data will override.", clusterName))
+	}
 	if len(clusterInfo.CertificateAuthority) != 0 {
 		clientCertCA, err := os.Open(clusterInfo.CertificateAuthority)
 		defer clientCertCA.Close()
@@ -129,6 +133,9 @@ func validateAuthInfo(authInfoName string, authInfo clientcmdapi.AuthInfo) []err
 	if len(authInfo.Token) != 0 {
 		methods = append(methods, "token")
 	}
+	if len(authInfo.Username) != 0 || len(authInfo.Password) != 0 {
+		methods = append(methods, "basicAuth")
+	}
 	if len(authInfo.AuthPath) != 0 {
 		usingAuthPath = true
 		methods = append(methods, "authFile")
@@ -140,18 +147,34 @@ func validateAuthInfo(authInfoName string, authInfo clientcmdapi.AuthInfo) []err
 			validationErrors = append(validationErrors, fmt.Errorf("unable to read auth-path %v for %v due to %v", authInfo.AuthPath, authInfoName, err))
 		}
 	}
-	if len(authInfo.ClientCertificate) != 0 {
-		methods = append(methods, "clientCert")
 
-		clientCertFile, err := os.Open(authInfo.ClientCertificate)
-		defer clientCertFile.Close()
-		if err != nil {
-			validationErrors = append(validationErrors, fmt.Errorf("unable to read client-cert %v for %v due to %v", authInfo.ClientCertificate, authInfoName, err))
+	if len(authInfo.ClientCertificate) != 0 || len(authInfo.ClientCertificateData) != 0 {
+		// Make sure cert data and file aren't both specified
+		if len(authInfo.ClientCertificate) != 0 && len(authInfo.ClientCertificateData) != 0 {
+			validationErrors = append(validationErrors, fmt.Errorf("client-cert-data and client-cert are both specified for %v. client-cert-data will override.", authInfoName))
 		}
-		clientKeyFile, err := os.Open(authInfo.ClientKey)
-		defer clientKeyFile.Close()
-		if err != nil {
-			validationErrors = append(validationErrors, fmt.Errorf("unable to read client-key %v for %v due to %v", authInfo.ClientKey, authInfoName, err))
+		// Make sure key data and file aren't both specified
+		if len(authInfo.ClientKey) != 0 && len(authInfo.ClientKeyData) != 0 {
+			validationErrors = append(validationErrors, fmt.Errorf("client-key-data and client-key are both specified for %v. client-key-data will override.", authInfoName))
+		}
+		// Make sure a key is specified
+		if len(authInfo.ClientKey) == 0 && len(authInfo.ClientKeyData) == 0 {
+			validationErrors = append(validationErrors, fmt.Errorf("client-key-data or client-key must be specified for %v to use the clientCert authentication method.", authInfoName))
+		}
+
+		if len(authInfo.ClientCertificate) != 0 {
+			clientCertFile, err := os.Open(authInfo.ClientCertificate)
+			defer clientCertFile.Close()
+			if err != nil {
+				validationErrors = append(validationErrors, fmt.Errorf("unable to read client-cert %v for %v due to %v", authInfo.ClientCertificate, authInfoName, err))
+			}
+		}
+		if len(authInfo.ClientKey) != 0 {
+			clientKeyFile, err := os.Open(authInfo.ClientKey)
+			defer clientKeyFile.Close()
+			if err != nil {
+				validationErrors = append(validationErrors, fmt.Errorf("unable to read client-key %v for %v due to %v", authInfo.ClientKey, authInfoName, err))
+			}
 		}
 	}
 

pkg/client/clientcmd/validation_test.go

@@ -244,6 +244,25 @@ func TestValidateCertFilesNotFoundAuthInfo(t *testing.T) {
 	test.testAuthInfo("error", t)
 	test.testConfig(t)
 }
+func TestValidateCertDataOverridesFiles(t *testing.T) {
+	tempFile, _ := ioutil.TempFile("", "")
+	defer os.Remove(tempFile.Name())
+
+	config := clientcmdapi.NewConfig()
+	config.AuthInfos["clean"] = clientcmdapi.AuthInfo{
+		ClientCertificate:     tempFile.Name(),
+		ClientCertificateData: []byte("certdata"),
+		ClientKey:             tempFile.Name(),
+		ClientKeyData:         []byte("keydata"),
+	}
+	test := configValidationTest{
+		config:                 config,
+		expectedErrorSubstring: []string{"client-cert-data and client-cert are both specified", "client-key-data and client-key are both specified"},
+	}
+
+	test.testAuthInfo("clean", t)
+	test.testConfig(t)
+}
 func TestValidateCleanCertFilesAuthInfo(t *testing.T) {
 	tempFile, _ := ioutil.TempFile("", "")
 	defer os.Remove(tempFile.Name())
@@ -288,6 +307,21 @@ func TestValidateCleanTokenAuthInfo(t *testing.T) {
 	test.testConfig(t)
 }
 
+func TestValidateMultipleMethodsAuthInfo(t *testing.T) {
+	config := clientcmdapi.NewConfig()
+	config.AuthInfos["error"] = clientcmdapi.AuthInfo{
+		Token:    "token",
+		Username: "username",
+	}
+	test := configValidationTest{
+		config:                 config,
+		expectedErrorSubstring: []string{"more than one authentication method", "token", "basicAuth"},
+	}
+
+	test.testAuthInfo("error", t)
+	test.testConfig(t)
+}
+
 type configValidationTest struct {
 	config                 *clientcmdapi.Config
 	expectedErrorSubstring []string

pkg/client/helper.go

@@ -346,7 +346,9 @@ func IsConfigTransportTLS(config Config) bool {
 func defaultServerUrlFor(config *Config) (*url.URL, error) {
 	// TODO: move the default to secure when the apiserver supports TLS by default
 	// config.Insecure is taken to mean "I want HTTPS but don't bother checking the certs against a CA."
-	defaultTLS := config.CertFile != "" || config.Insecure
+	hasCA := len(config.CAFile) != 0 || len(config.CAData) != 0
+	hasCert := len(config.CertFile) != 0 || len(config.CertData) != 0
+	defaultTLS := hasCA || hasCert || config.Insecure
 	host := config.Host
 	if host == "" {
 		host = "localhost"

pkg/kubectl/cmd/config/create_authinfo.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -35,20 +36,35 @@ type createAuthInfoOptions struct {
 	clientCertificate util.StringFlag
 	clientKey         util.StringFlag
 	token             util.StringFlag
+	username          util.StringFlag
+	password          util.StringFlag
 }
 
 func NewCmdConfigSetAuthInfo(out io.Writer, pathOptions *pathOptions) *cobra.Command {
 	options := &createAuthInfoOptions{pathOptions: pathOptions}
 
 	cmd := &cobra.Command{
-		Use:   fmt.Sprintf("set-credentials name [--%v=path/to/auth/file] [--%v=path/to/certficate/file] [--%v=path/to/key/file] [--%v=bearer_token_string]", clientcmd.FlagAuthPath, clientcmd.FlagCertFile, clientcmd.FlagKeyFile, clientcmd.FlagBearerToken),
+		Use:   fmt.Sprintf("set-credentials name [--%v=authfile] [--%v=certfile] [--%v=keyfile] [--%v=bearer_token] [--%v=basic_user] [--%v=basic_password]", clientcmd.FlagAuthPath, clientcmd.FlagCertFile, clientcmd.FlagKeyFile, clientcmd.FlagBearerToken, clientcmd.FlagUsername, clientcmd.FlagPassword),
 		Short: "Sets a user entry in .kubeconfig",
-		Long: `Sets a user entry in .kubeconfig
-	Specifying a name that already exists will merge new fields on top of existing values for those fields.
-	e.g. 
-		kubectl config set-credentials cluster-admin --client-key=~/.kube/cluster-admin/.kubecfg.key
-		only sets the client-key field on the cluster-admin user entry without touching other values.
-		`,
+		Long: fmt.Sprintf(`Sets a user entry in .kubeconfig
+
+  Specifying a name that already exists will merge new fields on top of existing
+  values. For example, the following only sets the "client-key" field on the 
+  "cluster-admin" entry, without touching other values:
+
+    set-credentials cluster-admin --client-key=~/.kube/admin.key
+
+  Client-certificate flags:
+    --%v=certfile --%v=keyfile
+
+  Bearer token flags:
+    --%v=bearer_token
+
+  Basic auth flags:
+    --%v=basic_user --%v=basic_password
+
+  Bearer token and basic auth are mutually exclusive.
+`, clientcmd.FlagCertFile, clientcmd.FlagKeyFile, clientcmd.FlagBearerToken, clientcmd.FlagUsername, clientcmd.FlagPassword),
 		Run: func(cmd *cobra.Command, args []string) {
 			if !options.complete(cmd) {
 				return
@@ -56,7 +72,7 @@ func NewCmdConfigSetAuthInfo(out io.Writer, pathOptions *pathOptions) *cobra.Com
 
 			err := options.run()
 			if err != nil {
-				fmt.Printf("%v\n", err)
+				fmt.Fprintf(out, "%v\n", err)
 			}
 		},
 	}
@@ -65,6 +81,8 @@ func NewCmdConfigSetAuthInfo(out io.Writer, pathOptions *pathOptions) *cobra.Com
 	cmd.Flags().Var(&options.clientCertificate, clientcmd.FlagCertFile, clientcmd.FlagCertFile+" for the user entry in .kubeconfig")
 	cmd.Flags().Var(&options.clientKey, clientcmd.FlagKeyFile, clientcmd.FlagKeyFile+" for the user entry in .kubeconfig")
 	cmd.Flags().Var(&options.token, clientcmd.FlagBearerToken, clientcmd.FlagBearerToken+" for the user entry in .kubeconfig")
+	cmd.Flags().Var(&options.username, clientcmd.FlagUsername, clientcmd.FlagUsername+" for the user entry in .kubeconfig")
+	cmd.Flags().Var(&options.password, clientcmd.FlagPassword, clientcmd.FlagPassword+" for the user entry in .kubeconfig")
 
 	return cmd
 }
@@ -95,17 +113,48 @@ func (o createAuthInfoOptions) run() error {
 func (o *createAuthInfoOptions) modifyAuthInfo(existingAuthInfo clientcmdapi.AuthInfo) clientcmdapi.AuthInfo {
 	modifiedAuthInfo := existingAuthInfo
 
+	var setToken, setBasic bool
+
 	if o.authPath.Provided() {
 		modifiedAuthInfo.AuthPath = o.authPath.Value()
 	}
+
 	if o.clientCertificate.Provided() {
 		modifiedAuthInfo.ClientCertificate = o.clientCertificate.Value()
+		if len(modifiedAuthInfo.ClientCertificate) > 0 {
+			modifiedAuthInfo.ClientCertificateData = nil
+		}
 	}
 	if o.clientKey.Provided() {
 		modifiedAuthInfo.ClientKey = o.clientKey.Value()
+		if len(modifiedAuthInfo.ClientKey) > 0 {
+			modifiedAuthInfo.ClientKeyData = nil
+		}
 	}
+
 	if o.token.Provided() {
 		modifiedAuthInfo.Token = o.token.Value()
+		setToken = len(modifiedAuthInfo.Token) > 0
+	}
+
+	if o.username.Provided() {
+		modifiedAuthInfo.Username = o.username.Value()
+		setBasic = setBasic || len(modifiedAuthInfo.Username) > 0
+	}
+	if o.password.Provided() {
+		modifiedAuthInfo.Password = o.password.Value()
+		setBasic = setBasic || len(modifiedAuthInfo.Password) > 0
+	}
+
+	// If any auth info was set, make sure any other existing auth types are cleared
+	if setToken || setBasic {
+		if !setToken {
+			modifiedAuthInfo.Token = ""
+		}
+		if !setBasic {
+			modifiedAuthInfo.Username = ""
+			modifiedAuthInfo.Password = ""
+		}
 	}
 
 	return modifiedAuthInfo
@@ -126,6 +175,16 @@ func (o createAuthInfoOptions) validate() error {
 	if len(o.name) == 0 {
 		return errors.New("You must specify a non-empty user name")
 	}
+	methods := []string{}
+	if len(o.token.Value()) > 0 {
+		methods = append(methods, fmt.Sprintf("--%v", clientcmd.FlagBearerToken))
+	}
+	if len(o.username.Value()) > 0 || len(o.password.Value()) > 0 {
+		methods = append(methods, fmt.Sprintf("--%v/--%v", clientcmd.FlagUsername, clientcmd.FlagPassword))
+	}
+	if len(methods) > 1 {
+		return fmt.Errorf("You cannot specify more than one authentication method at the same time: %v", strings.Join(methods, ", "))
+	}
 
 	return nil
 }

pkg/kubectl/cmd/config/create_cluster.go

@@ -56,7 +56,7 @@ func NewCmdConfigSetCluster(out io.Writer, pathOptions *pathOptions) *cobra.Comm
 
 			err := options.run()
 			if err != nil {
-				fmt.Printf("%v\n", err)
+				fmt.Fprintf(out, "%v\n", err)
 			}
 		},
 	}
@@ -109,9 +109,19 @@ func (o *createClusterOptions) modifyCluster(existingCluster clientcmdapi.Cluste
 	}
 	if o.insecureSkipTLSVerify.Provided() {
 		modifiedCluster.InsecureSkipTLSVerify = o.insecureSkipTLSVerify.Value()
+		// Specifying insecure mode clears any certificate authority
+		if modifiedCluster.InsecureSkipTLSVerify {
+			modifiedCluster.CertificateAuthority = ""
+			modifiedCluster.CertificateAuthorityData = nil
+		}
 	}
 	if o.certificateAuthority.Provided() {
 		modifiedCluster.CertificateAuthority = o.certificateAuthority.Value()
+		// Specifying a certificate authority file clears certificate authority data and insecure mode
+		if modifiedCluster.CertificateAuthority != "" {
+			modifiedCluster.CertificateAuthorityData = nil
+			modifiedCluster.InsecureSkipTLSVerify = false
+		}
 	}
 
 	return modifiedCluster
@@ -132,6 +142,9 @@ func (o createClusterOptions) validate() error {
 	if len(o.name) == 0 {
 		return errors.New("You must specify a non-empty cluster name")
 	}
+	if o.insecureSkipTLSVerify.Value() && o.certificateAuthority.Value() != "" {
+		return errors.New("You cannot specify a certificate authority and insecure mode at the same time")
+	}
 
 	return nil
 }