Remove deprecated io/ioutil (#15707)

internal/config/certs.go

@@ -23,7 +23,7 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"errors"
-	"io/ioutil"
+	"os"
 
 	"github.com/minio/pkg/env"
 )
@@ -37,7 +37,7 @@ const EnvCertPassword = "MINIO_CERT_PASSWD"
 func ParsePublicCertFile(certFile string) (x509Certs []*x509.Certificate, err error) {
 	// Read certificate file.
 	var data []byte
-	if data, err = ioutil.ReadFile(certFile); err != nil {
+	if data, err = os.ReadFile(certFile); err != nil {
 		return nil, err
 	}
 
@@ -71,11 +71,11 @@ func ParsePublicCertFile(certFile string) (x509Certs []*x509.Certificate, err er
 // from the provided paths. The private key may be encrypted and is
 // decrypted using the ENV_VAR: MINIO_CERT_PASSWD.
 func LoadX509KeyPair(certFile, keyFile string) (tls.Certificate, error) {
-	certPEMBlock, err := ioutil.ReadFile(certFile)
+	certPEMBlock, err := os.ReadFile(certFile)
 	if err != nil {
 		return tls.Certificate{}, ErrSSLUnexpectedError(err)
 	}
-	keyPEMBlock, err := ioutil.ReadFile(keyFile)
+	keyPEMBlock, err := os.ReadFile(keyFile)
 	if err != nil {
 		return tls.Certificate{}, ErrSSLUnexpectedError(err)
 	}

internal/config/certs_test.go

@@ -18,7 +18,6 @@
 package config
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 )
@@ -26,7 +25,7 @@ import (
 func createTempFile(prefix, content string) (tempFile string, err error) {
 	var tmpfile *os.File
 
-	if tmpfile, err = ioutil.TempFile("", prefix); err != nil {
+	if tmpfile, err = os.CreateTemp("", prefix); err != nil {
 		return tempFile, err
 	}
 

internal/config/crypto_test.go

@@ -21,7 +21,6 @@ import (
 	"bytes"
 	"encoding/hex"
 	"io"
-	"io/ioutil"
 	"testing"
 
 	"github.com/minio/minio/internal/kms"
@@ -64,7 +63,7 @@ func TestEncryptDecrypt(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Test %d: failed to encrypt stream: %v", i, err)
 		}
-		data, err := ioutil.ReadAll(ciphertext)
+		data, err := io.ReadAll(ciphertext)
 		if err != nil {
 			t.Fatalf("Test %d: failed to encrypt stream: %v", i, err)
 		}
@@ -73,7 +72,7 @@ func TestEncryptDecrypt(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Test %d: failed to decrypt stream: %v", i, err)
 		}
-		data, err = ioutil.ReadAll(plaintext)
+		data, err = io.ReadAll(plaintext)
 		if err != nil {
 			t.Fatalf("Test %d: failed to decrypt stream: %v", i, err)
 		}
@@ -106,7 +105,7 @@ func BenchmarkEncrypt(b *testing.B) {
 			if err != nil {
 				b.Fatal(err)
 			}
-			if _, err = io.Copy(ioutil.Discard, ciphertext); err != nil {
+			if _, err = io.Copy(io.Discard, ciphertext); err != nil {
 				b.Fatal(err)
 			}
 			plaintext.Reset(data)

internal/config/policy/opa/config.go

@@ -21,7 +21,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/minio/minio/internal/config"
@@ -194,7 +193,7 @@ func (o *Opa) IsAllowed(args iampolicy.Args) (bool, error) {
 	defer o.args.CloseRespFn(resp.Body)
 
 	// Read the body to be saved later.
-	opaRespBytes, err := ioutil.ReadAll(resp.Body)
+	opaRespBytes, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return false, err
 	}

internal/config/policy/plugin/config.go

@@ -21,7 +21,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/minio/minio/internal/config"
@@ -188,7 +187,7 @@ func (o *AuthZPlugin) IsAllowed(args iampolicy.Args) (bool, error) {
 	defer o.args.CloseRespFn(resp.Body)
 
 	// Read the body to be saved later.
-	opaRespBytes, err := ioutil.ReadAll(resp.Body)
+	opaRespBytes, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return false, err
 	}

internal/config/subnet/subnet.go

@@ -23,7 +23,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"time"
 
@@ -62,7 +61,7 @@ func (c Config) Post(reqURL string, payload interface{}) (string, error) {
 	}
 	defer xhttp.DrainBody(resp.Body)
 
-	respBytes, err := ioutil.ReadAll(io.LimitReader(resp.Body, respBodyLimit))
+	respBytes, err := io.ReadAll(io.LimitReader(resp.Body, respBodyLimit))
 	if err != nil {
 		return "", err
 	}