chore: remove refs to deprecated io/ioutil

pkg/webhook/util/health/checker.go

@@ -20,8 +20,8 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
-	"io/ioutil"
 	"net/http"
+	"os"
 	"path"
 	"sync"
 
@@ -40,7 +40,7 @@ var (
 )
 
 func loadHTTPClientWithCACert() error {
-	caCert, err := ioutil.ReadFile(caCertFilePath)
+	caCert, err := os.ReadFile(caCertFilePath)
 	if err != nil {
 		return err
 	}

pkg/webhook/util/writer/fs.go

@@ -20,7 +20,6 @@ package writer
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path"
 
@@ -158,19 +157,19 @@ func (f *fsCertWriter) read() (*generator.Artifacts, error) {
 	if err := ensureExist(f.Path); err != nil {
 		return nil, err
 	}
-	caKeyBytes, err := ioutil.ReadFile(path.Join(f.Path, CAKeyName))
+	caKeyBytes, err := os.ReadFile(path.Join(f.Path, CAKeyName))
 	if err != nil {
 		return nil, err
 	}
-	caCertBytes, err := ioutil.ReadFile(path.Join(f.Path, CACertName))
+	caCertBytes, err := os.ReadFile(path.Join(f.Path, CACertName))
 	if err != nil {
 		return nil, err
 	}
-	certBytes, err := ioutil.ReadFile(path.Join(f.Path, ServerCertName))
+	certBytes, err := os.ReadFile(path.Join(f.Path, ServerCertName))
 	if err != nil {
 		return nil, err
 	}
-	keyBytes, err := ioutil.ReadFile(path.Join(f.Path, ServerKeyName))
+	keyBytes, err := os.ReadFile(path.Join(f.Path, ServerKeyName))
 	if err != nil {
 		return nil, err
 	}

test/e2e/framework/test_context.go

@@ -20,7 +20,6 @@ package framework
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"time"
 
@@ -346,7 +345,7 @@ func AfterReadingAllFlags(t *TestContextType) {
 	if len(t.Host) == 0 && len(t.KubeConfig) == 0 {
 		// Check if we can use the in-cluster config
 		if clusterConfig, err := restclient.InClusterConfig(); err == nil {
-			if tempFile, err := ioutil.TempFile(os.TempDir(), "kubeconfig-"); err == nil {
+			if tempFile, err := os.CreateTemp(os.TempDir(), "kubeconfig-"); err == nil {
 				kubeConfig := createKubeConfig(clusterConfig)
 				clientcmd.WriteToFile(*kubeConfig, tempFile.Name())
 				t.KubeConfig = tempFile.Name()

test/e2e/framework/testfiles/testfiles.go

@@ -30,7 +30,6 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
@@ -123,7 +122,7 @@ func (r RootFileSource) ReadTestFile(filePath string) ([]byte, error) {
 	} else {
 		fullPath = filepath.Join(r.Root, filePath)
 	}
-	data, err := ioutil.ReadFile(fullPath)
+	data, err := os.ReadFile(fullPath)
 	if os.IsNotExist(err) {
 		// Not an error (yet), some other provider may have the file.
 		return nil, nil