Use FindExistingKubeConfig in the phases which use the --kubeconfig

cmd/kubeadm/app/cmd/BUILD

@@ -66,7 +66,6 @@ go_library(
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
         "//staging/src/k8s.io/client-go/tools/bootstrap/token/api:go_default_library",
         "//staging/src/k8s.io/client-go/tools/bootstrap/token/util:go_default_library",
-        "//staging/src/k8s.io/client-go/tools/clientcmd:go_default_library",
         "//staging/src/k8s.io/client-go/tools/clientcmd/api:go_default_library",
         "//staging/src/k8s.io/client-go/util/cert:go_default_library",
         "//vendor/github.com/ghodss/yaml:go_default_library",

cmd/kubeadm/app/cmd/phases/bootstraptoken.go

@@ -31,7 +31,7 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/validation"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
-	kubeadmconstants"k8s.io/kubernetes/cmd/kubeadm/app/constants"
+	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	"k8s.io/kubernetes/cmd/kubeadm/app/phases/bootstraptoken/clusterinfo"
 	"k8s.io/kubernetes/cmd/kubeadm/app/phases/bootstraptoken/node"
 	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
@@ -99,6 +99,7 @@ func NewCmdBootstrapToken() *cobra.Command {
 	options.AddKubeConfigFlag(cmd.PersistentFlags(), &kubeConfigFile)
 
 	// Add subcommands
+	kubeConfigFile = cmdutil.FindExistingKubeConfig(kubeConfigFile)
 	cmd.AddCommand(NewSubCmdBootstrapTokenAll(&kubeConfigFile))
 	cmd.AddCommand(NewSubCmdBootstrapToken(&kubeConfigFile))
 	cmd.AddCommand(NewSubCmdClusterInfo(&kubeConfigFile))

cmd/kubeadm/app/cmd/phases/kubelet.go

@@ -208,6 +208,7 @@ func NewCmdKubeletConfigUpload() *cobra.Command {
 			internalcfg, err := configutil.ConfigFileAndDefaultsToInternalConfig(cfgPath, cfg)
 			kubeadmutil.CheckErr(err)
 
+			kubeConfigFile = cmdutil.FindExistingKubeConfig(kubeConfigFile)
 			client, err := kubeconfigutil.ClientSetFromFile(kubeConfigFile)
 			kubeadmutil.CheckErr(err)
 
@@ -310,6 +311,7 @@ func NewCmdKubeletConfigEnableDynamic() *cobra.Command {
 			kubeletVersion, err := version.ParseSemantic(kubeletVersionStr)
 			kubeadmutil.CheckErr(err)
 
+			kubeConfigFile = cmdutil.FindExistingKubeConfig(kubeConfigFile)
 			client, err := kubeconfigutil.ClientSetFromFile(kubeConfigFile)
 			kubeadmutil.CheckErr(err)
 

cmd/kubeadm/app/cmd/upgrade/upgrade.go

@@ -18,7 +18,6 @@ package upgrade
 
 import (
 	"io"
-	"path/filepath"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -47,7 +46,7 @@ type applyPlanFlags struct {
 // NewCmdUpgrade returns the cobra command for `kubeadm upgrade`
 func NewCmdUpgrade(out io.Writer) *cobra.Command {
 	flags := &applyPlanFlags{
-		kubeConfigPath:            filepath.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.AdminKubeConfigFileName),
+		kubeConfigPath:            kubeadmconstants.GetAdminKubeConfigPath(),
 		cfgPath:                   "",
 		featureGatesString:        "",
 		allowExperimentalUpgrades: false,
@@ -63,6 +62,7 @@ func NewCmdUpgrade(out io.Writer) *cobra.Command {
 		RunE:  cmdutil.SubCmdRunE("upgrade"),
 	}
 
+	flags.kubeConfigPath = cmdutil.FindExistingKubeConfig(flags.kubeConfigPath)
 	cmd.AddCommand(NewCmdApply(flags))
 	cmd.AddCommand(NewCmdPlan(flags))
 	cmd.AddCommand(NewCmdDiff(out))

cmd/kubeadm/app/cmd/util/cmdutil.go

@@ -18,9 +18,9 @@ package util
 
 import (
 	"fmt"
-	"path/filepath"
 
 	"github.com/spf13/cobra"
+
 	"k8s.io/client-go/tools/clientcmd"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 )
@@ -65,12 +65,12 @@ func ValidateExactArgNumber(args []string, supportedArgs []string) error {
 func FindExistingKubeConfig(file string) string {
 	// The user did provide a --kubeconfig flag. Respect that and threat it as an
 	// explicit path without building a DefaultClientConfigLoadingRules object.
-	if file != filepath.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.AdminKubeConfigFileName) {
+	if file != kubeadmconstants.GetAdminKubeConfigPath() {
 		return file
 	}
 	// The user did not provide a --kubeconfig flag. Find a config in the standard
 	// locations using DefaultClientConfigLoadingRules, but also consider the default config path.
 	rules := clientcmd.NewDefaultClientConfigLoadingRules()
-	rules.Precedence = append(rules.Precedence, filepath.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.AdminKubeConfigFileName))
+	rules.Precedence = append(rules.Precedence, kubeadmconstants.GetAdminKubeConfigPath())
 	return rules.GetDefaultFilename()
 }