replace ioutil with os, update doc

pkg/kubeapiserver/admission/config.go

@@ -17,8 +17,8 @@ limitations under the License.
 package admission
 
 import (
-	"io/ioutil"
 	"net/http"
+	"os"
 	"time"
 
 	"k8s.io/klog/v2"
@@ -55,7 +55,7 @@ func (c *Config) New(proxyTransport *http.Transport, egressSelector *egressselec
 	var cloudConfig []byte
 	if c.CloudConfigFile != "" {
 		var err error
-		cloudConfig, err = ioutil.ReadFile(c.CloudConfigFile)
+		cloudConfig, err = os.ReadFile(c.CloudConfigFile)
 		if err != nil {
 			klog.Fatalf("Error reading from cloud configuration file %s: %#v", c.CloudConfigFile, err)
 		}

pkg/kubelet/kubeletconfig/util/files/files.go

@@ -91,7 +91,7 @@ func WriteTmpFile(fs utilfs.Filesystem, path string, data []byte) (tmpPath strin
 		}
 	}()
 
-	// Name() will be an absolute path when using utilfs.DefaultFS, because ioutil.TempFile passes
+	// Name() will be an absolute path when using utilfs.DefaultFS, because os.CreateTemp passes
 	// an absolute path to os.Open, and we ensure similar behavior in utilfs.FakeFS for testing.
 	tmpPath = tmpFile.Name()
 

pkg/kubelet/kuberuntime/logs/logs_test.go

@@ -22,7 +22,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -407,7 +406,7 @@ func TestReadLogsLimitsWithTimestamps(t *testing.T) {
 	logLineFmt := "2022-10-29T16:10:22.592603036-05:00 stdout P %v\n"
 	logLineNewLine := "2022-10-29T16:10:22.592603036-05:00 stdout F \n"
 
-	tmpfile, err := ioutil.TempFile("", "log.*.txt")
+	tmpfile, err := os.CreateTemp("", "log.*.txt")
 	assert.NoError(t, err)
 
 	count := 10000

pkg/kubelet/prober/common_test.go

@@ -17,7 +17,7 @@ limitations under the License.
 package prober
 
 import (
-	"io/ioutil"
+	"os"
 	"reflect"
 	"sync"
 
@@ -111,7 +111,7 @@ func newTestManager() *manager {
 	// Add test pod to pod manager, so that status manager can get the pod from pod manager if needed.
 	podManager.AddPod(getTestPod())
 	testRootDir := ""
-	if tempDir, err := ioutil.TempDir("", "kubelet_test."); err != nil {
+	if tempDir, err := os.MkdirTemp("", "kubelet_test."); err != nil {
 		return nil
 	} else {
 		testRootDir = tempDir

pkg/kubelet/prober/scale_test.go

@@ -19,9 +19,9 @@ package prober
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"net/http"
+	"os"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -82,7 +82,7 @@ func TestTCPPortExhaustion(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(fmt.Sprintf(tt.name), func(t *testing.T) {
 			testRootDir := ""
-			if tempDir, err := ioutil.TempDir("", "kubelet_test."); err != nil {
+			if tempDir, err := os.MkdirTemp("", "kubelet_test."); err != nil {
 				t.Fatalf("can't make a temp rootdir: %v", err)
 			} else {
 				testRootDir = tempDir

pkg/kubelet/prober/worker_test.go

@@ -19,7 +19,7 @@ package prober
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"testing"
 	"time"
 
@@ -155,7 +155,7 @@ func TestDoProbe(t *testing.T) {
 
 			// Clean up.
 			testRootDir := ""
-			if tempDir, err := ioutil.TempDir("", "kubelet_test."); err != nil {
+			if tempDir, err := os.MkdirTemp("", "kubelet_test."); err != nil {
 				t.Fatalf("can't make a temp rootdir: %v", err)
 			} else {
 				testRootDir = tempDir

pkg/kubelet/status/status_manager_test.go

@@ -18,8 +18,8 @@ package status
 
 import (
 	"fmt"
-	"io/ioutil"
 	"math/rand"
+	"os"
 	"reflect"
 	"strconv"
 	"strings"
@@ -90,7 +90,7 @@ func newTestManager(kubeClient clientset.Interface) *manager {
 	podManager.AddPod(getTestPod())
 	podStartupLatencyTracker := util.NewPodStartupLatencyTracker()
 	testRootDir := ""
-	if tempDir, err := ioutil.TempDir("", "kubelet_test."); err != nil {
+	if tempDir, err := os.MkdirTemp("", "kubelet_test."); err != nil {
 		return nil
 	} else {
 		testRootDir = tempDir

pkg/util/filesystem/defaultfs.go

@@ -85,7 +85,7 @@ func (fs *DefaultFs) RemoveAll(path string) error {
 	return os.RemoveAll(fs.prefix(path))
 }
 
-// Remove via os.RemoveAll
+// Remove via os.Remove
 func (fs *DefaultFs) Remove(name string) error {
 	return os.Remove(fs.prefix(name))
 }

pkg/util/filesystem/filesystem.go

@@ -33,7 +33,7 @@ type Filesystem interface {
 	RemoveAll(path string) error
 	Remove(name string) error
 
-	// from "io/ioutil"
+	// from "os"
 	ReadFile(filename string) ([]byte, error)
 	TempDir(dir, prefix string) (string, error)
 	TempFile(dir, prefix string) (File, error)