From f0aa126b03761b025e24a3fc2967dd0e2bead434 Mon Sep 17 00:00:00 2001
From: Silvin Lubecki <silvin.lubecki@docker.com>
Date: Fri, 30 Mar 2018 18:04:38 +0200
Subject: [PATCH] Fix using the namespace specified in the kubeconfig file.

Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>
---
 cli/command/stack/kubernetes/cli.go | 20 ++++++++++++++------
 cli/command/system/version.go       |  3 ++-
 kubernetes/config.go                | 14 ++++++++------
 3 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/cli/command/stack/kubernetes/cli.go b/cli/command/stack/kubernetes/cli.go
index 27064ba087..4984f2b0e0 100644
--- a/cli/command/stack/kubernetes/cli.go
+++ b/cli/command/stack/kubernetes/cli.go
@@ -43,11 +43,7 @@ func NewOptions(flags *flag.FlagSet) Options {
 func WrapCli(dockerCli command.Cli, opts Options) (*KubeCli, error) {
 	var err error
 	cli := &KubeCli{
-		Cli:           dockerCli,
-		kubeNamespace: "default",
-	}
-	if opts.Namespace != "" {
-		cli.kubeNamespace = opts.Namespace
+		Cli: dockerCli,
 	}
 	kubeConfig := opts.Config
 	if kubeConfig == "" {
@@ -57,7 +53,19 @@ func WrapCli(dockerCli command.Cli, opts Options) (*KubeCli, error) {
 			kubeConfig = filepath.Join(homedir.Get(), ".kube/config")
 		}
 	}
-	config, err := kubernetes.NewKubernetesConfig(kubeConfig)
+
+	clientConfig := kubernetes.NewKubernetesConfig(kubeConfig)
+
+	cli.kubeNamespace = opts.Namespace
+	if opts.Namespace == "default" {
+		configNamespace, _, err := clientConfig.Namespace()
+		if err != nil {
+			return nil, err
+		}
+		cli.kubeNamespace = configNamespace
+	}
+
+	config, err := clientConfig.ClientConfig()
 	if err != nil {
 		return nil, err
 	}
diff --git a/cli/command/system/version.go b/cli/command/system/version.go
index c8e3654cbd..e925843b3d 100644
--- a/cli/command/system/version.go
+++ b/cli/command/system/version.go
@@ -228,7 +228,8 @@ func getKubernetesVersion(dockerCli command.Cli, kubeConfig string) *kubernetesV
 		Kubernetes: "Unknown",
 		StackAPI:   "Unknown",
 	}
-	config, err := kubernetes.NewKubernetesConfig(kubeConfig)
+	clientConfig := kubernetes.NewKubernetesConfig(kubeConfig)
+	config, err := clientConfig.ClientConfig()
 	if err != nil {
 		logrus.Debugf("failed to get Kubernetes configuration: %s", err)
 		return &version
diff --git a/kubernetes/config.go b/kubernetes/config.go
index 3a9fdfc6dc..287a6a6bf0 100644
--- a/kubernetes/config.go
+++ b/kubernetes/config.go
@@ -5,14 +5,13 @@ import (
 	"path/filepath"
 
 	"github.com/docker/docker/pkg/homedir"
-	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 )
 
-// NewKubernetesConfig resolves the path to the desired Kubernetes configuration file, depending
-// environment variable and command line flag.
-func NewKubernetesConfig(configFlag string) (*restclient.Config, error) {
-	kubeConfig := configFlag
+// NewKubernetesConfig resolves the path to the desired Kubernetes configuration file based on
+// the KUBECONFIG environment variable and command line flags.
+func NewKubernetesConfig(configPath string) clientcmd.ClientConfig {
+	kubeConfig := configPath
 	if kubeConfig == "" {
 		if config := os.Getenv("KUBECONFIG"); config != "" {
 			kubeConfig = config
@@ -20,5 +19,8 @@ func NewKubernetesConfig(configFlag string) (*restclient.Config, error) {
 			kubeConfig = filepath.Join(homedir.Get(), ".kube/config")
 		}
 	}
-	return clientcmd.BuildConfigFromFlags("", kubeConfig)
+
+	return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		&clientcmd.ClientConfigLoadingRules{ExplicitPath: kubeConfig},
+		&clientcmd.ConfigOverrides{})
 }