cli: stop using deprecated io/ioutil

This replaces deprecated ioutil variables and functions as follows:

* ioutil.Discard -> io.Discard
* ioutil.NopCloser -> io.NopCloser
* ioutil.ReadAll -> io.ReadAll
* ioutil.ReadFile -> os.ReadFile
* ioutil.TempFile -> os.CreateTemp

Signed-off-by: Stephen Kitt <skitt@redhat.com>

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/io_options.go

@@ -18,7 +18,7 @@ package genericclioptions
 
 import (
 	"bytes"
-	"io/ioutil"
+	"io"
 
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 )
@@ -48,7 +48,7 @@ func NewTestIOStreamsDiscard() genericiooptions.IOStreams {
 	in := &bytes.Buffer{}
 	return IOStreams{
 		In:     in,
-		Out:    ioutil.Discard,
+		Out:    io.Discard,
-		ErrOut: ioutil.Discard,
+		ErrOut: io.Discard,
 	}
 }

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/jsonpath_flags.go

@@ -18,7 +18,7 @@ package genericclioptions
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"sort"
 	"strings"
 
@@ -88,7 +88,7 @@ func (f *JSONPathPrintFlags) ToPrinter(templateFormat string) (printers.Resource
 	}
 
 	if templateFormat == "jsonpath-file" {
-		data, err := ioutil.ReadFile(templateValue)
+		data, err := os.ReadFile(templateValue)
 		if err != nil {
 			return nil, fmt.Errorf("error reading --template %s, %v", templateValue, err)
 		}

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/jsonpath_flags_test.go

@@ -19,7 +19,6 @@ package genericclioptions
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"sort"
 	"strings"
@@ -32,7 +31,7 @@ import (
 func TestPrinterSupportsExpectedJSONPathFormats(t *testing.T) {
 	testObject := &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "foo"}}
 
-	jsonpathFile, err := ioutil.TempFile("", "printers_jsonpath_flags")
+	jsonpathFile, err := os.CreateTemp("", "printers_jsonpath_flags")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/template_flags.go

@@ -18,7 +18,7 @@ package genericclioptions
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"sort"
 	"strings"
 
@@ -89,7 +89,7 @@ func (f *GoTemplatePrintFlags) ToPrinter(templateFormat string) (printers.Resour
 	}
 
 	if templateFormat == "templatefile" || templateFormat == "go-template-file" {
-		data, err := ioutil.ReadFile(templateValue)
+		data, err := os.ReadFile(templateValue)
 		if err != nil {
 			return nil, fmt.Errorf("error reading --template %s, %v", templateValue, err)
 		}

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/template_flags_test.go

@@ -19,7 +19,6 @@ package genericclioptions
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"sort"
 	"strings"
@@ -32,7 +31,7 @@ import (
 func TestPrinterSupportsExpectedTemplateFormats(t *testing.T) {
 	testObject := &v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "foo"}}
 
-	templateFile, err := ioutil.TempFile("", "printers_jsonpath_flags")
+	templateFile, err := os.CreateTemp("", "printers_jsonpath_flags")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

staging/src/k8s.io/cli-runtime/pkg/resource/helper_test.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"reflect"
 	"strings"
@@ -39,7 +38,7 @@ import (
 )
 
 func objBody(obj runtime.Object) io.ReadCloser {
-	return ioutil.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(corev1Codec, obj))))
+	return io.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(corev1Codec, obj))))
 }
 
 func header() http.Header {
@@ -250,7 +249,7 @@ func TestHelperCreate(t *testing.T) {
 			if tt.Req != nil && !tt.Req(client.Req) {
 				t.Errorf("%d: unexpected request: %#v", i, client.Req)
 			}
-			body, err := ioutil.ReadAll(client.Req.Body)
+			body, err := io.ReadAll(client.Req.Body)
 			if err != nil {
 				t.Fatalf("%d: unexpected error: %#v", i, err)
 			}
@@ -711,7 +710,7 @@ func TestHelperReplace(t *testing.T) {
 			if tt.Req != nil && (client.Req == nil || !tt.Req(tt.ExpectPath, client.Req)) {
 				t.Fatalf("unexpected request: %#v", client.Req)
 			}
-			body, err := ioutil.ReadAll(client.Req.Body)
+			body, err := io.ReadAll(client.Req.Body)
 			if err != nil {
 				t.Fatalf("unexpected error: %#v", err)
 			}

staging/src/k8s.io/cli-runtime/pkg/resource/visitor_test.go

@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -75,7 +74,7 @@ func TestVisitorHttpGet(t *testing.T) {
 			httpRetries: func(url string) (int, string, io.ReadCloser, error) {
 				assert.Equal(t, "hello", url)
 				i++
-				return 501, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+				return 501, "Status", io.NopCloser(new(bytes.Buffer)), nil
 			},
 			args: httpArgs{
 				duration: 0,
@@ -89,7 +88,7 @@ func TestVisitorHttpGet(t *testing.T) {
 			httpRetries: func(url string) (int, string, io.ReadCloser, error) {
 				assert.Equal(t, "hello", url)
 				i++
-				return 300, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+				return 300, "Status", io.NopCloser(new(bytes.Buffer)), nil
 
 			},
 			args: httpArgs{
@@ -104,7 +103,7 @@ func TestVisitorHttpGet(t *testing.T) {
 			httpRetries: func(url string) (int, string, io.ReadCloser, error) {
 				assert.Equal(t, "hello", url)
 				i++
-				return 501, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+				return 501, "Status", io.NopCloser(new(bytes.Buffer)), nil
 
 			},
 			args: httpArgs{
@@ -117,7 +116,7 @@ func TestVisitorHttpGet(t *testing.T) {
 		{
 			name: "Test attempts less than 1 results in an error",
 			httpRetries: func(url string) (int, string, io.ReadCloser, error) {
-				return 200, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+				return 200, "Status", io.NopCloser(new(bytes.Buffer)), nil
 
 			},
 			args: httpArgs{
@@ -133,9 +132,9 @@ func TestVisitorHttpGet(t *testing.T) {
 				assert.Equal(t, "hello", url)
 				i++
 				if i > 1 {
-					return 200, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+					return 200, "Status", io.NopCloser(new(bytes.Buffer)), nil
 				}
-				return 501, "Status", ioutil.NopCloser(new(bytes.Buffer)), nil
+				return 501, "Status", io.NopCloser(new(bytes.Buffer)), nil
 
 			},
 			args: httpArgs{