Merge pull request #60565 from WanLinghao/kubectl_cp_slash

Automatic merge from submit-queue (batch tested with PRs 60990, 60947, 45275, 60565, 61091). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

kubectl cp command bug fix

**What this PR does / why we need it**:
	when copy file from host to pod like this:	
        1.kubectl copy /tmp/test-file test-pod:/
	2.kubectl copy /tmp/test-file test-pod:
	example 1 will fail, example 2 will cause a panic.
	This patch fix bugs above.


**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #60564

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

pkg/kubectl/cmd/cp.go

@@ -162,13 +162,13 @@ func checkDestinationIsDir(dest fileSpec, f cmdutil.Factory, cmd *cobra.Command)
 }
 
 func copyToPod(f cmdutil.Factory, cmd *cobra.Command, stdout, stderr io.Writer, src, dest fileSpec) error {
-	if len(src.File) == 0 {
+	if len(src.File) == 0 || len(dest.File) == 0 {
 		return errFileCannotBeEmpty
 	}
 	reader, writer := io.Pipe()
 
 	// strip trailing slash (if any)
-	if strings.HasSuffix(string(dest.File[len(dest.File)-1]), "/") {
+	if dest.File != "/" && strings.HasSuffix(string(dest.File[len(dest.File)-1]), "/") {
 		dest.File = dest.File[:len(dest.File)-1]
 	}
 
@@ -209,7 +209,7 @@ func copyToPod(f cmdutil.Factory, cmd *cobra.Command, stdout, stderr io.Writer,
 }
 
 func copyFromPod(f cmdutil.Factory, cmd *cobra.Command, cmderr io.Writer, src, dest fileSpec) error {
-	if len(src.File) == 0 {
+	if len(src.File) == 0 || len(dest.File) == 0 {
 		return errFileCannotBeEmpty
 	}
 

pkg/kubectl/cmd/cp_test.go

@@ -21,12 +21,22 @@ import (
 	"bytes"
 	"io"
 	"io/ioutil"
+	"net/http"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/rest/fake"
+	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	cmdtesting "k8s.io/kubernetes/pkg/kubectl/cmd/testing"
+	"k8s.io/kubernetes/pkg/kubectl/scheme"
 )
 
 type FileType int
@@ -497,3 +507,72 @@ func TestClean(t *testing.T) {
 		}
 	}
 }
+
+func TestCopyToPod(t *testing.T) {
+	tf := cmdtesting.NewTestFactory()
+	tf.Namespace = "test"
+	ns := legacyscheme.Codecs
+	codec := legacyscheme.Codecs.LegacyCodec(scheme.Versions...)
+
+	tf.Client = &fake.RESTClient{
+		GroupVersion:         schema.GroupVersion{Group: "", Version: "v1"},
+		NegotiatedSerializer: ns,
+		Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
+			responsePod := &v1.Pod{}
+			return &http.Response{StatusCode: http.StatusNotFound, Header: defaultHeader(), Body: ioutil.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(codec, responsePod))))}, nil
+		}),
+	}
+
+	tf.ClientConfigVal = defaultClientConfig()
+	buf := bytes.NewBuffer([]byte{})
+	errBuf := bytes.NewBuffer([]byte{})
+	cmd := NewCmdCp(tf, buf, errBuf)
+
+	srcFile, err := ioutil.TempDir("", "test")
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+		t.FailNow()
+	}
+	defer os.RemoveAll(srcFile)
+
+	tests := map[string]struct {
+		dest        string
+		expectedErr bool
+	}{
+		"copy to directory": {
+			dest:        "/tmp/",
+			expectedErr: false,
+		},
+		"copy to root": {
+			dest:        "/",
+			expectedErr: false,
+		},
+		"copy to empty file name": {
+			dest:        "",
+			expectedErr: true,
+		},
+	}
+
+	for name, test := range tests {
+		src := fileSpec{
+			File: srcFile,
+		}
+		dest := fileSpec{
+			PodNamespace: "pod-ns",
+			PodName:      "pod-name",
+			File:         test.dest,
+		}
+		t.Run(name, func(t *testing.T) {
+			err = copyToPod(tf, cmd, buf, errBuf, src, dest)
+			//If error is NotFound error , it indicates that the
+			//request has been sent correctly.
+			//Treat this as no error.
+			if test.expectedErr && errors.IsNotFound(err) {
+				t.Errorf("expected error but didn't get one")
+			}
+			if !test.expectedErr && !errors.IsNotFound(err) {
+				t.Errorf("unexpected error: %v", err)
+			}
+		})
+	}
+}