replace deprecated io/ioutil with os and io for cmd

cmd/kube-proxy/app/conntrack.go

@@ -18,7 +18,7 @@ package app
 
 import (
 	"errors"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 
@@ -132,7 +132,7 @@ func isSysFSWritable() (bool, error) {
 }
 
 func readIntStringFile(filename string) (int, error) {
-	b, err := ioutil.ReadFile(filename)
+	b, err := os.ReadFile(filename)
 	if err != nil {
 		return -1, err
 	}
@@ -140,5 +140,5 @@ func readIntStringFile(filename string) (int, error) {
 }
 
 func writeIntStringFile(filename string, value int) error {
-	return ioutil.WriteFile(filename, []byte(strconv.Itoa(value)), 0640)
+	return os.WriteFile(filename, []byte(strconv.Itoa(value)), 0640)
 }

cmd/kube-proxy/app/server.go

@@ -22,7 +22,6 @@ import (
 	"errors"
 	goflag "flag"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"os"
@@ -403,7 +402,7 @@ func newLenientSchemeAndCodecs() (*runtime.Scheme, *serializer.CodecFactory, err
 // loadConfigFromFile loads the contents of file and decodes it as a
 // KubeProxyConfiguration object.
 func (o *Options) loadConfigFromFile(file string) (*kubeproxyconfig.KubeProxyConfiguration, error) {
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return nil, err
 	}

cmd/kube-proxy/app/server_test.go

@@ -19,7 +19,6 @@ package app
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -406,7 +405,7 @@ func TestProcessHostnameOverrideFlag(t *testing.T) {
 
 func TestConfigChange(t *testing.T) {
 	setUp := func() (*os.File, string, error) {
-		tempDir, err := ioutil.TempDir("", "kubeproxy-config-change")
+		tempDir, err := os.MkdirTemp("", "kubeproxy-config-change")
 		if err != nil {
 			return nil, "", fmt.Errorf("unable to create temporary directory: %v", err)
 		}