Gracefully handle empty config error when local flag is used

`f.ToRawKubeConfigLoader().Namespace()` throws `ErrEmptyConfig` when
default configuration file can not be found, even if it invalid.

However, when user explicitly passes `--local` flag, that means
we can gracefully handle this error and continue. This commit does that
for the commands having `--local` flag.

staging/src/k8s.io/kubectl/pkg/cmd/annotate/annotate.go

@@ -32,6 +32,8 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/json"
 
+	"k8s.io/client-go/tools/clientcmd"
+
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
@@ -227,7 +229,7 @@ func (flags *AnnotateFlags) ToOptions(f cmdutil.Factory, cmd *cobra.Command, arg
 	}
 
 	options.namespace, options.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(options.local && clientcmd.IsEmptyConfig(err)) {
 		return nil, err
 	}
 	options.builder = f.NewBuilder()

staging/src/k8s.io/kubectl/pkg/cmd/label/label.go

@@ -38,6 +38,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/scheme"
 	"k8s.io/kubectl/pkg/util/completion"
@@ -204,7 +205,7 @@ func (o *LabelOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []st
 	}
 
 	o.namespace, o.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}
 	o.builder = f.NewBuilder()

staging/src/k8s.io/kubectl/pkg/cmd/patch/patch.go

@@ -40,6 +40,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/scheme"
 	"k8s.io/kubectl/pkg/util/completion"
@@ -171,7 +172,7 @@ func (o *PatchOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []st
 	}
 
 	o.namespace, o.enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.Local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}
 	o.args = args

staging/src/k8s.io/kubectl/pkg/cmd/set/set_image.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/polymorphichelpers"
 	"k8s.io/kubectl/pkg/scheme"
@@ -167,7 +168,7 @@ func (o *SetImageOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args [
 	o.PrintObj = printer.PrintObj
 
 	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.Local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}
 

staging/src/k8s.io/kubectl/pkg/cmd/set/set_resources.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	generateversioned "k8s.io/kubectl/pkg/generate/versioned"
 	"k8s.io/kubectl/pkg/polymorphichelpers"
@@ -166,7 +167,7 @@ func (o *SetResourcesOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, ar
 	o.PrintObj = printer.PrintObj
 
 	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.Local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}
 

staging/src/k8s.io/kubectl/pkg/cmd/set/set_serviceaccount.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/polymorphichelpers"
 	"k8s.io/kubectl/pkg/scheme"
@@ -149,7 +150,7 @@ func (o *SetServiceAccountOptions) Complete(f cmdutil.Factory, cmd *cobra.Comman
 	o.PrintObj = printer.PrintObj
 
 	cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}
 	if len(args) == 0 {

staging/src/k8s.io/kubectl/pkg/cmd/set/set_subject.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/cli-runtime/pkg/printers"
 	"k8s.io/cli-runtime/pkg/resource"
+	"k8s.io/client-go/tools/clientcmd"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/scheme"
 	"k8s.io/kubectl/pkg/util/i18n"
@@ -138,7 +139,7 @@ func (o *SubjectOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []
 
 	var enforceNamespace bool
 	o.namespace, enforceNamespace, err = f.ToRawKubeConfigLoader().Namespace()
-	if err != nil {
+	if err != nil && !(o.Local && clientcmd.IsEmptyConfig(err)) {
 		return err
 	}