From 5e31a6bb744d829561c7ecde9166a3c0ac21203d Mon Sep 17 00:00:00 2001
From: Yago Nobre <nobre.yago@gmail.com>
Date: Fri, 9 Nov 2018 15:39:17 -0200
Subject: [PATCH] Handler error when kubeconfig file not exist on kubeadm reset

---
 cmd/kubeadm/app/cmd/reset.go      | 19 ++++++++++++-------
 cmd/kubeadm/app/cmd/reset_test.go | 27 +++++++++++++++++++++------
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/cmd/kubeadm/app/cmd/reset.go b/cmd/kubeadm/app/cmd/reset.go
index 94def13805..70f112ebc6 100644
--- a/cmd/kubeadm/app/cmd/reset.go
+++ b/cmd/kubeadm/app/cmd/reset.go
@@ -18,7 +18,6 @@ package cmd
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -26,6 +25,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"k8s.io/klog"
 
@@ -51,6 +51,7 @@ func NewCmdReset(in io.Reader, out io.Writer) *cobra.Command {
 	var criSocketPath string
 	var ignorePreflightErrors []string
 	var forceReset bool
+	var client clientset.Interface
 	kubeConfigFile := kubeadmconstants.GetAdminKubeConfigPath()
 
 	cmd := &cobra.Command{
@@ -61,8 +62,10 @@ func NewCmdReset(in io.Reader, out io.Writer) *cobra.Command {
 			kubeadmutil.CheckErr(err)
 
 			kubeConfigFile = cmdutil.FindExistingKubeConfig(kubeConfigFile)
-			client, err := getClientset(kubeConfigFile, false)
-			kubeadmutil.CheckErr(err)
+			if _, err := os.Stat(kubeConfigFile); !os.IsNotExist(err) {
+				client, err = getClientset(kubeConfigFile, false)
+				kubeadmutil.CheckErr(err)
+			}
 
 			r, err := NewReset(in, ignorePreflightErrorsSet, forceReset, certsDir, criSocketPath)
 			kubeadmutil.CheckErr(err)
@@ -189,11 +192,13 @@ func getEtcdDataDir(manifestPath string, client clientset.Interface) (string, er
 	const etcdVolumeName = "etcd-data"
 	var dataDir string
 
-	cfg, err := configutil.FetchConfigFromFileOrCluster(client, os.Stdout, "reset", "", false)
-	if err == nil {
-		return cfg.Etcd.Local.DataDir, nil
+	if client != nil {
+		cfg, err := configutil.FetchConfigFromFileOrCluster(client, os.Stdout, "reset", "", false)
+		if err == nil {
+			return cfg.Etcd.Local.DataDir, nil
+		}
+		klog.Warningf("[reset] Unable to fetch the kubeadm-config ConfigMap, using etcd pod spec as fallback: %v", err)
 	}
-	klog.Warningf("[reset] Unable to fetch the kubeadm-config ConfigMap, using etcd pod spec as fallback: %v", err)
 
 	etcdPod, err := utilstaticpod.ReadStaticPodFromDisk(manifestPath)
 	if err != nil {
diff --git a/cmd/kubeadm/app/cmd/reset_test.go b/cmd/kubeadm/app/cmd/reset_test.go
index f15dec5039..063d59b6cb 100644
--- a/cmd/kubeadm/app/cmd/reset_test.go
+++ b/cmd/kubeadm/app/cmd/reset_test.go
@@ -273,30 +273,38 @@ func TestGetEtcdDataDir(t *testing.T) {
 		podYaml       string
 		expectErr     bool
 		writeManifest bool
+		validClient   bool
 	}{
 		"non-existent file returns error": {
-			dataDir:       "",
-			podYaml:       "",
 			expectErr:     true,
 			writeManifest: false,
+			validClient:   true,
 		},
 		"return etcd data dir": {
 			dataDir:       "/path/to/etcd",
 			podYaml:       etcdPod,
 			expectErr:     false,
 			writeManifest: true,
+			validClient:   true,
 		},
 		"invalid etcd pod": {
-			dataDir:       "",
 			podYaml:       etcdPodInvalid,
 			expectErr:     true,
 			writeManifest: true,
+			validClient:   true,
 		},
 		"etcd pod spec without data volume": {
-			dataDir:       "",
 			podYaml:       etcdPodWithoutDataVolume,
 			expectErr:     true,
 			writeManifest: true,
+			validClient:   true,
+		},
+		"kubeconfig file doesn't exist": {
+			dataDir:       "/path/to/etcd",
+			podYaml:       etcdPod,
+			expectErr:     false,
+			writeManifest: true,
+			validClient:   false,
 		},
 	}
 
@@ -312,8 +320,15 @@ func TestGetEtcdDataDir(t *testing.T) {
 			}
 		}
 
-		client := clientsetfake.NewSimpleClientset()
-		dataDir, err := getEtcdDataDir(manifestPath, client)
+		var dataDir string
+		var err error
+		if test.validClient {
+			client := clientsetfake.NewSimpleClientset()
+			dataDir, err = getEtcdDataDir(manifestPath, client)
+		} else {
+			dataDir, err = getEtcdDataDir(manifestPath, nil)
+		}
+
 		if (err != nil) != test.expectErr {
 			t.Fatalf(dedent.Dedent(
 				"getEtcdDataDir failed\n%s\nexpected error: %t\n\tgot: %t\nerror: %v"),