Merge pull request #16859 from smarterclayton/allow_incluster_config

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

@@ -31,6 +31,14 @@ func init() {
 	redactedBytes = []byte(string(sDec))
 }
 
+// IsConfigEmpty returns true if the config is empty.
+func IsConfigEmpty(config *Config) bool {
+	return len(config.AuthInfos) == 0 && len(config.Clusters) == 0 && len(config.Contexts) == 0 &&
+		len(config.CurrentContext) == 0 &&
+		len(config.Preferences.Extensions) == 0 && !config.Preferences.Colors &&
+		len(config.Extensions) == 0
+}
+
 // MinifyConfig read the current context and uses that to keep only the relevant pieces of config
 // This is useful for making secrets based on kubeconfig files
 func MinifyConfig(config *Config) error {

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

@@ -24,6 +24,7 @@ import (
 // Top level config objects and all values required for proper functioning are not "omitempty".  Any truly optional piece of config is allowed to be omitted.
 
 // Config holds the information needed to build connect to remote kubernetes clusters as a given user
+// IMPORTANT if you add fields to this struct, please update IsConfigEmpty()
 type Config struct {
 	// Legacy field from pkg/api/types.go TypeMeta.
 	// TODO(jlowdermilk): remove this after eliminating downstream dependencies.
@@ -44,6 +45,7 @@ type Config struct {
 	Extensions map[string]*runtime.EmbeddedObject `json:"extensions,omitempty"`
 }
 
+// IMPORTANT if you add fields to this struct, please update IsConfigEmpty()
 type Preferences struct {
 	Colors bool `json:"colors,omitempty"`
 	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields

pkg/client/unversioned/clientcmd/client_config.go

@@ -233,7 +233,11 @@ func (config DirectClientConfig) ConfirmUsable() error {
 	validationErrors := make([]error, 0)
 	validationErrors = append(validationErrors, validateAuthInfo(config.getAuthInfoName(), config.getAuthInfo())...)
 	validationErrors = append(validationErrors, validateClusterInfo(config.getClusterName(), config.getCluster())...)
-
+	// when direct client config is specified, and our only error is that no server is defined, we should
+	// return a standard "no config" error
+	if len(validationErrors) == 1 && validationErrors[0] == ErrEmptyCluster {
+		return newErrConfigurationInvalid([]error{ErrEmptyConfig})
+	}
 	return newErrConfigurationInvalid(validationErrors)
 }
 

pkg/client/unversioned/clientcmd/validation.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"reflect"
 	"strings"
 
 	clientcmdapi "k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api"
@@ -27,7 +28,12 @@ import (
 	"k8s.io/kubernetes/pkg/util/validation"
 )
 
-var ErrNoContext = errors.New("no context chosen")
+var (
+	ErrNoContext   = errors.New("no context chosen")
+	ErrEmptyConfig = errors.New("no configuration has been provided")
+	// message is for consistency with old behavior
+	ErrEmptyCluster = errors.New("cluster has no server defined")
+)
 
 type errContextNotFound struct {
 	ContextName string
@@ -49,6 +55,16 @@ func IsContextNotFound(err error) bool {
 	return strings.Contains(err.Error(), "context was not found for specified context")
 }
 
+// IsEmptyConfig returns true if the provided error indicates the provided configuration
+// is empty.
+func IsEmptyConfig(err error) bool {
+	switch t := err.(type) {
+	case errConfigurationInvalid:
+		return len(t) == 1 && t[0] == ErrEmptyConfig
+	}
+	return err == ErrEmptyConfig
+}
+
 // errConfigurationInvalid is a set of errors indicating the configuration is invalid.
 type errConfigurationInvalid []error
 
@@ -88,6 +104,10 @@ func IsConfigurationInvalid(err error) bool {
 func Validate(config clientcmdapi.Config) error {
 	validationErrors := make([]error, 0)
 
+	if clientcmdapi.IsConfigEmpty(&config) {
+		return newErrConfigurationInvalid([]error{ErrEmptyConfig})
+	}
+
 	if len(config.CurrentContext) != 0 {
 		if _, exists := config.Contexts[config.CurrentContext]; !exists {
 			validationErrors = append(validationErrors, &errContextNotFound{config.CurrentContext})
@@ -114,6 +134,10 @@ func Validate(config clientcmdapi.Config) error {
 func ConfirmUsable(config clientcmdapi.Config, passedContextName string) error {
 	validationErrors := make([]error, 0)
 
+	if clientcmdapi.IsConfigEmpty(&config) {
+		return newErrConfigurationInvalid([]error{ErrEmptyConfig})
+	}
+
 	var contextName string
 	if len(passedContextName) != 0 {
 		contextName = passedContextName
@@ -143,6 +167,10 @@ func ConfirmUsable(config clientcmdapi.Config, passedContextName string) error {
 func validateClusterInfo(clusterName string, clusterInfo clientcmdapi.Cluster) []error {
 	validationErrors := make([]error, 0)
 
+	if reflect.DeepEqual(clientcmdapi.Cluster{}, clusterInfo) {
+		return []error{ErrEmptyCluster}
+	}
+
 	if len(clusterInfo.Server) == 0 {
 		if len(clusterName) == 0 {
 			validationErrors = append(validationErrors, fmt.Errorf("default cluster has no server defined"))

pkg/client/unversioned/clientcmd/validation_test.go

@@ -87,7 +87,7 @@ func TestConfirmUsableEmptyConfig(t *testing.T) {
 	config := clientcmdapi.NewConfig()
 	test := configValidationTest{
 		config:                 config,
-		expectedErrorSubstring: []string{"no context chosen"},
+		expectedErrorSubstring: []string{"invalid configuration: no configuration has been provided"},
 	}
 
 	test.testConfirmUsable("", t)
@@ -96,7 +96,7 @@ func TestConfirmUsableMissingConfig(t *testing.T) {
 	config := clientcmdapi.NewConfig()
 	test := configValidationTest{
 		config:                 config,
-		expectedErrorSubstring: []string{"context was not found for"},
+		expectedErrorSubstring: []string{"invalid configuration: no configuration has been provided"},
 	}
 
 	test.testConfirmUsable("not-here", t)
@@ -104,7 +104,8 @@ func TestConfirmUsableMissingConfig(t *testing.T) {
 func TestValidateEmptyConfig(t *testing.T) {
 	config := clientcmdapi.NewConfig()
 	test := configValidationTest{
-		config: config,
+		config:                 config,
+		expectedErrorSubstring: []string{"invalid configuration: no configuration has been provided"},
 	}
 
 	test.testConfig(t)
@@ -132,6 +133,18 @@ func TestIsContextNotFound(t *testing.T) {
 	}
 }
 
+func TestIsEmptyConfig(t *testing.T) {
+	config := clientcmdapi.NewConfig()
+
+	err := Validate(*config)
+	if !IsEmptyConfig(err) {
+		t.Errorf("Expected context not found, but got %v", err)
+	}
+	if !IsConfigurationInvalid(err) {
+		t.Errorf("Expected configuration invalid, but got %v", err)
+	}
+}
+
 func TestIsConfigurationInvalid(t *testing.T) {
 	if newErrConfigurationInvalid([]error{}) != nil {
 		t.Errorf("unexpected error")
@@ -177,7 +190,7 @@ func TestValidateEmptyClusterInfo(t *testing.T) {
 	config.Clusters["empty"] = &clientcmdapi.Cluster{}
 	test := configValidationTest{
 		config:                 config,
-		expectedErrorSubstring: []string{"no server found for"},
+		expectedErrorSubstring: []string{"cluster has no server defined"},
 	}
 
 	test.testCluster("empty", t)

pkg/client/unversioned/helper.go

@@ -327,6 +327,11 @@ func NewOrDie(c *Config) *Client {
 // running inside a pod running on kuberenetes. It will return an error if
 // called from a process not running in a kubernetes environment.
 func InClusterConfig() (*Config, error) {
+	host, port := os.Getenv("KUBERNETES_SERVICE_HOST"), os.Getenv("KUBERNETES_SERVICE_PORT")
+	if len(host) == 0 || len(port) == 0 {
+		return nil, fmt.Errorf("unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined")
+	}
+
 	token, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/" + api.ServiceAccountTokenKey)
 	if err != nil {
 		return nil, err
@@ -341,7 +346,7 @@ func InClusterConfig() (*Config, error) {
 
 	return &Config{
 		// TODO: switch to using cluster DNS.
-		Host:            "https://" + net.JoinHostPort(os.Getenv("KUBERNETES_SERVICE_HOST"), os.Getenv("KUBERNETES_SERVICE_PORT")),
+		Host:            "https://" + net.JoinHostPort(host, port),
 		BearerToken:     string(token),
 		TLSClientConfig: tlsClientConfig,
 	}, nil