mount-utils: stop using ioutil in tests

io/ioutil is deprecated since Go 1.16. Besides, we now have a nice
t.TempDir() function which simplifies things a lot.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

staging/src/k8s.io/mount-utils/mount_helper_test.go

@@ -18,7 +18,6 @@ package mount
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -105,11 +104,7 @@ func TestDoCleanupMountPoint(t *testing.T) {
 
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {
-			tmpDir, err := ioutil.TempDir("", "unmount-mount-point-test")
-			if err != nil {
-				t.Fatalf("failed to create tmpdir: %v", err)
-			}
-			defer os.RemoveAll(tmpDir)
+			tmpDir := t.TempDir()
 
 			if tt.prepareMnt == nil {
 				t.Fatalf("prepareMnt function required")
@@ -150,15 +145,12 @@ func TestDoCleanupMountPoint(t *testing.T) {
 }
 
 func validateDirExists(dir string) error {
-	_, err := ioutil.ReadDir(dir)
-	if err != nil {
-		return err
-	}
-	return nil
+	_, err := os.ReadDir(dir)
+	return err
 }
 
 func validateDirNotExists(dir string) error {
-	_, err := ioutil.ReadDir(dir)
+	_, err := os.ReadDir(dir)
 	if os.IsNotExist(err) {
 		return nil
 	}

staging/src/k8s.io/mount-utils/mount_helper_unix_test.go

@@ -20,25 +20,19 @@ limitations under the License.
 package mount
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
 )
 
-func writeFile(content string) (string, string, error) {
-	tempDir, err := ioutil.TempDir("", "mounter_shared_test")
+func writeFile(t *testing.T, content string) string {
+	filename := filepath.Join(t.TempDir(), "mountinfo")
+	err := os.WriteFile(filename, []byte(content), 0o600)
 	if err != nil {
-		return "", "", err
+		t.Fatal(err)
 	}
-	filename := filepath.Join(tempDir, "mountinfo")
-	err = ioutil.WriteFile(filename, []byte(content), 0o600)
-	if err != nil {
-		os.RemoveAll(tempDir)
-		return "", "", err
-	}
-	return tempDir, filename, nil
+	return filename
 }
 
 func TestParseMountInfo(t *testing.T) {
@@ -84,11 +78,7 @@ func TestParseMountInfo(t *testing.T) {
 40 28 0:36 / /sys/fs/cgroup/perf_event rw,nosuid,nodev,noexec,relatime shared:22 - cgroup cgroup rw,perf_event
 761 60 8:0 / /var/lib/kubelet/plugins/kubernetes.io/iscsi/iface-default/127.0.0.1:3260-iqn.2003-01.org.linux-iscsi.f21.x8664:sn.4b0aae584f7c-lun-0 rw,relatime shared:421 - ext4 /dev/sda rw,context="system_u:object_r:container_file_t:s0:c314,c894",data=ordered
 `
-	tempDir, filename, err := writeFile(info)
-	if err != nil {
-		t.Fatalf("cannot create temporary file: %v", err)
-	}
-	defer os.RemoveAll(tempDir)
+	filename := writeFile(t, info)
 
 	tests := []struct {
 		name         string
@@ -303,11 +293,7 @@ func TestBadParseMountInfo(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		tempDir, filename, err := writeFile(test.info)
-		if err != nil {
-			t.Fatalf("cannot create temporary file: %v", err)
-		}
-		defer os.RemoveAll(tempDir)
+		filename := writeFile(t, test.info)
 
 		infos, err := ParseMountInfo(filename)
 		if err != nil {

staging/src/k8s.io/mount-utils/mount_linux_test.go

@@ -22,7 +22,6 @@ package mount
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"reflect"
@@ -430,7 +429,7 @@ func TestSearchMountPoints(t *testing.T) {
 			nil,
 		},
 	}
-	tmpFile, err := ioutil.TempFile("", "test-get-filetype")
+	tmpFile, err := os.CreateTemp("", "test-get-filetype")
 	if err != nil {
 		t.Fatal(err)
 	}

staging/src/k8s.io/mount-utils/mount_windows_test.go

@@ -21,7 +21,6 @@ package mount
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -200,12 +199,7 @@ func TestIsLikelyNotMountPoint(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		base, err := ioutil.TempDir("", test.fileName)
-		if err != nil {
-			t.Fatalf(err.Error())
-		}
-
-		defer os.RemoveAll(base)
+		base := t.TempDir()
 
 		if err := test.setUp(base, test.fileName, test.targetLinkName); err != nil {
 			t.Fatalf("unexpected error in setUp(%s, %s): %v", test.fileName, test.targetLinkName, err)
@@ -280,13 +274,7 @@ func TestFormatAndMount(t *testing.T) {
 			Interface: &fakeMounter,
 			Exec:      fakeExec,
 		}
-		base, err := ioutil.TempDir("", test.device)
-		if err != nil {
-			t.Fatalf(err.Error())
-		}
-		defer os.RemoveAll(base)
-
-		target := filepath.Join(base, test.target)
+		target := filepath.Join(t.TempDir(), test.target)
 		err = mounter.FormatAndMount(test.device, target, test.fstype, test.mountOptions)
 		if test.expectError {
 			assert.NotNil(t, err, "Expect error during FormatAndMount(%s, %s, %s, %v)", test.device, test.target, test.fstype, test.mountOptions)

staging/src/k8s.io/mount-utils/safe_format_and_mount_test.go

@@ -18,8 +18,6 @@ package mount
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
 	"runtime"
 	"strings"
 	"testing"
@@ -58,11 +56,6 @@ func TestSafeFormatAndMount(t *testing.T) {
 	if runtime.GOOS == "darwin" || runtime.GOOS == "windows" {
 		t.Skipf("not supported on GOOS=%s", runtime.GOOS)
 	}
-	mntDir, err := ioutil.TempDir(os.TempDir(), "mount")
-	if err != nil {
-		t.Fatalf("failed to create tmp dir: %v", err)
-	}
-	defer os.RemoveAll(mntDir)
 	tests := []struct {
 		description           string
 		fstype                string
@@ -241,7 +234,7 @@ func TestSafeFormatAndMount(t *testing.T) {
 		}
 
 		device := "/dev/foo"
-		dest := mntDir
+		dest := t.TempDir()
 		var err error
 		if len(test.formatOptions) > 0 {
 			err = mounter.FormatAndMountSensitiveWithFormatOptions(device, dest, test.fstype, test.mountOptions, test.sensitiveMountOptions, test.formatOptions)