refactor: move from io/ioutil to io and os package

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

pkg/cri/server/helpers_linux_test.go

@@ -17,7 +17,6 @@
 package server
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -66,11 +65,11 @@ func TestEnsureRemoveAllWithMount(t *testing.T) {
 		t.Skip("skipping test that requires root")
 	}
 
-	dir1, err := ioutil.TempDir("", "test-ensure-removeall-with-dir1")
+	dir1, err := os.MkdirTemp("", "test-ensure-removeall-with-dir1")
 	if err != nil {
 		t.Fatal(err)
 	}
-	dir2, err := ioutil.TempDir("", "test-ensure-removeall-with-dir2")
+	dir2, err := os.MkdirTemp("", "test-ensure-removeall-with-dir2")
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/cri/server/helpers_test.go

@@ -18,7 +18,7 @@ package server
 
 import (
 	"context"
-	"io/ioutil"
+	"os"
 	"testing"
 	"time"
 
@@ -489,7 +489,7 @@ func TestEnsureRemoveAllNotExist(t *testing.T) {
 }
 
 func TestEnsureRemoveAllWithDir(t *testing.T) {
-	dir, err := ioutil.TempDir("", "test-ensure-removeall-with-dir")
+	dir, err := os.MkdirTemp("", "test-ensure-removeall-with-dir")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -499,7 +499,7 @@ func TestEnsureRemoveAllWithDir(t *testing.T) {
 }
 
 func TestEnsureRemoveAllWithFile(t *testing.T) {
-	tmp, err := ioutil.TempFile("", "test-ensure-removeall-with-dir")
+	tmp, err := os.CreateTemp("", "test-ensure-removeall-with-dir")
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/cri/server/image_pull.go

@@ -21,10 +21,10 @@ import (
 	"crypto/x509"
 	"encoding/base64"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"path/filepath"
 	"strings"
 	"time"
@@ -301,7 +301,7 @@ func (c *criService) getTLSConfig(registryTLSConfig criconfig.TLSConfig) (*tls.C
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to get system cert pool")
 		}
-		caCert, err := ioutil.ReadFile(registryTLSConfig.CAFile)
+		caCert, err := os.ReadFile(registryTLSConfig.CAFile)
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to load CA file")
 		}

pkg/cri/server/restart.go

@@ -17,7 +17,6 @@
 package server
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	goruntime "runtime"
@@ -458,7 +457,7 @@ func (c *criService) loadImages(ctx context.Context, cImages []containerd.Image)
 
 func cleanupOrphanedIDDirs(ctx context.Context, cntrs []containerd.Container, base string) error {
 	// Cleanup orphaned id directories.
-	dirs, err := ioutil.ReadDir(base)
+	dirs, err := os.ReadDir(base)
 	if err != nil && !os.IsNotExist(err) {
 		return errors.Wrap(err, "failed to read base directory")
 	}

pkg/cri/server/service_test.go

@@ -18,7 +18,6 @@ package server
 
 import (
 	"encoding/json"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -73,7 +72,7 @@ func newTestCRIService() *criService {
 func TestLoadBaseOCISpec(t *testing.T) {
 	spec := oci.Spec{Version: "1.0.2", Hostname: "default"}
 
-	file, err := ioutil.TempFile("", "spec-test-")
+	file, err := os.CreateTemp("", "spec-test-")
 	require.NoError(t, err)
 
 	defer func() {

pkg/cri/server/update_runtime_config_test.go

@@ -17,7 +17,6 @@
 package server
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -94,11 +93,11 @@ func TestUpdateRuntimeConfig(t *testing.T) {
 		},
 	} {
 		t.Run(name, func(t *testing.T) {
-			testDir, err := ioutil.TempDir(os.TempDir(), "test-runtime-config")
+			testDir, err := os.MkdirTemp(os.TempDir(), "test-runtime-config")
 			require.NoError(t, err)
 			defer os.RemoveAll(testDir)
 			templateName := filepath.Join(testDir, "template")
-			err = ioutil.WriteFile(templateName, []byte(testTemplate), 0666)
+			err = os.WriteFile(templateName, []byte(testTemplate), 0666)
 			require.NoError(t, err)
 			confDir := filepath.Join(testDir, "net.d")
 			confName := filepath.Join(confDir, cniConfigFileName)
@@ -131,7 +130,7 @@ func TestUpdateRuntimeConfig(t *testing.T) {
 				_, err := os.Stat(confName)
 				assert.Error(t, err)
 			} else {
-				got, err := ioutil.ReadFile(confName)
+				got, err := os.ReadFile(confName)
 				assert.NoError(t, err)
 				assert.Equal(t, expected, string(got))
 			}