replace deprecated io/ioutil with os and io for cmd

cmd/clicheck/check_cli_conventions.go

@@ -18,7 +18,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 
 	"k8s.io/cli-runtime/pkg/genericclioptions"
@@ -29,7 +29,7 @@ import (
 func main() {
 	var errorCount int
 
-	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: os.Stdin, Out: ioutil.Discard, ErrOut: ioutil.Discard}})
+	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: os.Stdin, Out: io.Discard, ErrOut: io.Discard}})
 	errors := cmdsanity.RunCmdChecks(kubectl, cmdsanity.AllCmdChecks, []string{})
 	for _, err := range errors {
 		errorCount++

cmd/dependencycheck/dependencycheck.go

@@ -25,8 +25,8 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
+	"os"
 	"regexp"
 )
 
@@ -65,7 +65,7 @@ func main() {
 			log.Fatalf("Error compiling excluded package regex: %v", err)
 		}
 	}
-	b, err := ioutil.ReadFile(args[0])
+	b, err := os.ReadFile(args[0])
 	if err != nil {
 		log.Fatalf("Error reading dependencies file: %v", err)
 	}

cmd/dependencyverifier/dependencyverifier.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -81,7 +80,7 @@ func runCommand(cmd ...string) (string, error) {
 }
 
 func readFile(path string) (string, error) {
-	content, err := ioutil.ReadFile(path)
+	content, err := os.ReadFile(path)
 	// Convert []byte to string and print to screen
 	return string(content), err
 }

cmd/gendocs/gen_kubectl_docs.go

@@ -19,7 +19,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 
 	"github.com/spf13/cobra/doc"
@@ -47,6 +47,6 @@ func main() {
 	// Set environment variables used by kubectl so the output is consistent,
 	// regardless of where we run.
 	os.Setenv("HOME", "/home/username")
-	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: ioutil.Discard, ErrOut: ioutil.Discard}})
+	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: io.Discard, ErrOut: io.Discard}})
 	doc.GenMarkdownTree(kubectl, outDir)
 }

cmd/genkubedocs/gen_kube_docs.go

@@ -19,7 +19,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 
 	"github.com/spf13/cobra/doc"
@@ -79,7 +79,7 @@ func main() {
 		pflag.CommandLine = pflag.NewFlagSet(os.Args[0], pflag.ExitOnError)
 
 		// generate docs for kubeadm
-		kubeadm := kubeadmapp.NewKubeadmCommand(bytes.NewReader(nil), ioutil.Discard, ioutil.Discard)
+		kubeadm := kubeadmapp.NewKubeadmCommand(bytes.NewReader(nil), io.Discard, io.Discard)
 		doc.GenMarkdownTree(kubeadm, outDir)
 
 		// cleanup generated code for usage as include in the website

cmd/genkubedocs/postprocessing.go

@@ -17,7 +17,7 @@ limitations under the License.
 package main
 
 import (
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -38,14 +38,14 @@ func MarkdownPostProcessing(cmd *cobra.Command, dir string, processor func(strin
 	basename := strings.Replace(cmd.CommandPath(), " ", "_", -1) + ".md"
 	filename := filepath.Join(dir, basename)
 
-	markdownBytes, err := ioutil.ReadFile(filename)
+	markdownBytes, err := os.ReadFile(filename)
 	if err != nil {
 		return err
 	}
 
 	processedMarkDown := processor(string(markdownBytes))
 
-	return ioutil.WriteFile(filename, []byte(processedMarkDown), 0644)
+	return os.WriteFile(filename, []byte(processedMarkDown), 0644)
 }
 
 // cleanupForInclude parts of markdown that will make difficult to use it as include in the website:

cmd/genman/gen_kube_man.go

@@ -19,7 +19,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 
@@ -97,14 +97,14 @@ func main() {
 		}
 	case "kubectl":
 		// generate manpage for kubectl
-		kubectl := kubectlcmd.NewKubectlCommand(kubectlcmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: ioutil.Discard, ErrOut: ioutil.Discard}})
+		kubectl := kubectlcmd.NewKubectlCommand(kubectlcmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: io.Discard, ErrOut: io.Discard}})
 		genMarkdown(kubectl, "", outDir)
 		for _, c := range kubectl.Commands() {
 			genMarkdown(c, "kubectl", outDir)
 		}
 	case "kubeadm":
 		// generate manpage for kubeadm
-		kubeadm := kubeadmapp.NewKubeadmCommand(bytes.NewReader(nil), ioutil.Discard, ioutil.Discard)
+		kubeadm := kubeadmapp.NewKubeadmCommand(bytes.NewReader(nil), io.Discard, io.Discard)
 		genMarkdown(kubeadm, "", outDir)
 		for _, c := range kubeadm.Commands() {
 			genMarkdown(c, "kubeadm", outDir)

cmd/genyaml/gen_kubectl_yaml.go

@@ -19,7 +19,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 
@@ -66,7 +66,7 @@ func main() {
 	// Set environment variables used by kubectl so the output is consistent,
 	// regardless of where we run.
 	os.Setenv("HOME", "/home/username")
-	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: ioutil.Discard, ErrOut: ioutil.Discard}})
+	kubectl := cmd.NewKubectlCommand(cmd.KubectlOptions{IOStreams: genericclioptions.IOStreams{In: bytes.NewReader(nil), Out: io.Discard, ErrOut: io.Discard}})
 	genYaml(kubectl, "", outDir)
 	for _, c := range kubectl.Commands() {
 		genYaml(c, "kubectl", outDir)

cmd/importverifier/importverifier.go

@@ -21,7 +21,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -216,7 +215,7 @@ func main() {
 }
 
 func loadImportRestrictions(configFile string) ([]ImportRestriction, error) {
-	config, err := ioutil.ReadFile(configFile)
+	config, err := os.ReadFile(configFile)
 	if err != nil {
 		return nil, fmt.Errorf("failed to load configuration from %s: %v", configFile, err)
 	}

cmd/kube-apiserver/app/testing/testserver.go

@@ -19,7 +19,6 @@ package testing
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"path"
@@ -127,7 +126,7 @@ func StartTestServer(t Logger, instanceOptions *TestServerInstanceOptions, custo
 		}
 	}()
 
-	result.TmpDir, err = ioutil.TempDir("", "kubernetes-kube-apiserver")
+	result.TmpDir, err = os.MkdirTemp("", "kubernetes-kube-apiserver")
 	if err != nil {
 		return result, fmt.Errorf("failed to create temp dir: %v", err)
 	}
@@ -156,7 +155,7 @@ func StartTestServer(t Logger, instanceOptions *TestServerInstanceOptions, custo
 			return result, err
 		}
 		proxyCACertFile := path.Join(s.SecureServing.ServerCert.CertDirectory, "proxy-ca.crt")
-		if err := ioutil.WriteFile(proxyCACertFile, testutil.EncodeCertPEM(proxySigningCert), 0644); err != nil {
+		if err := os.WriteFile(proxyCACertFile, testutil.EncodeCertPEM(proxySigningCert), 0644); err != nil {
 			return result, err
 		}
 		s.Authentication.RequestHeader.ClientCAFile = proxyCACertFile
@@ -169,7 +168,7 @@ func StartTestServer(t Logger, instanceOptions *TestServerInstanceOptions, custo
 			return result, err
 		}
 		clientCACertFile := path.Join(s.SecureServing.ServerCert.CertDirectory, "client-ca.crt")
-		if err := ioutil.WriteFile(clientCACertFile, testutil.EncodeCertPEM(clientSigningCert), 0644); err != nil {
+		if err := os.WriteFile(clientCACertFile, testutil.EncodeCertPEM(clientSigningCert), 0644); err != nil {
 			return result, err
 		}
 		s.Authentication.ClientCert.ClientCA = clientCACertFile
@@ -191,12 +190,12 @@ func StartTestServer(t Logger, instanceOptions *TestServerInstanceOptions, custo
 		return result, err
 	}
 
-	saSigningKeyFile, err := ioutil.TempFile("/tmp", "insecure_test_key")
+	saSigningKeyFile, err := os.CreateTemp("/tmp", "insecure_test_key")
 	if err != nil {
 		t.Fatalf("create temp file failed: %v", err)
 	}
 	defer os.RemoveAll(saSigningKeyFile.Name())
-	if err = ioutil.WriteFile(saSigningKeyFile.Name(), []byte(ecdsaPrivateKey), 0666); err != nil {
+	if err = os.WriteFile(saSigningKeyFile.Name(), []byte(ecdsaPrivateKey), 0666); err != nil {
 		t.Fatalf("write file %s failed: %v", saSigningKeyFile.Name(), err)
 	}
 	s.ServiceAccountSigningKeyFile = saSigningKeyFile.Name()

cmd/kube-controller-manager/app/controllermanager.go

@@ -23,7 +23,6 @@ package app
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"math/rand"
 	"net/http"
 	"os"
@@ -646,7 +645,7 @@ func (c serviceAccountTokenControllerStarter) startServiceAccountTokenController
 }
 
 func readCA(file string) ([]byte, error) {
-	rootCA, err := ioutil.ReadFile(file)
+	rootCA, err := os.ReadFile(file)
 	if err != nil {
 		return nil, err
 	}

cmd/kube-controller-manager/app/testing/testserver.go

@@ -19,7 +19,6 @@ package testing
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"time"
@@ -73,7 +72,7 @@ func StartTestServer(t Logger, customFlags []string) (result TestServer, err err
 		}
 	}()
 
-	result.TmpDir, err = ioutil.TempDir("", "kube-controller-manager")
+	result.TmpDir, err = os.MkdirTemp("", "kube-controller-manager")
 	if err != nil {
 		return result, fmt.Errorf("failed to create temp dir: %v", err)
 	}

cmd/kube-proxy/app/conntrack.go

@@ -18,7 +18,7 @@ package app
 
 import (
 	"errors"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 
@@ -132,13 +132,13 @@ 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
 	}
 	return strconv.Atoi(strings.TrimSpace(string(b)))
 }
 
 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)
 		}

cmd/kube-scheduler/app/options/configfile.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 
 	"k8s.io/apimachinery/pkg/runtime"
@@ -32,7 +31,7 @@ import (
 )
 
 func loadConfigFromFile(file string) (*config.KubeSchedulerConfiguration, error) {
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return nil, err
 	}