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

The io/ioutil package has been deprecated in Go 1.16. 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>

3 files changed, 10 insertions, 11 deletions

diff --git a/integration/plugin/authz/authz_plugin_test.go b/integration/plugin/authz/authz_plugin_test.go
index 6cce66cd6c..3c8cfc6a65 100644
--- a/integration/plugin/authz/authz_plugin_test.go
+++ b/integration/plugin/authz/authz_plugin_test.go
@@ -7,7 +7,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/http/httputil"
@@ -61,7 +60,7 @@ func setupTestV1(t *testing.T) func() {
 	assert.NilError(t, err)
 
 	fileName := fmt.Sprintf("/etc/docker/plugins/%s.spec", testAuthZPlugin)
-	err = ioutil.WriteFile(fileName, []byte(server.URL), 0644)
+	err = os.WriteFile(fileName, []byte(server.URL), 0644)
 	assert.NilError(t, err)
 
 	return func() {
@@ -336,7 +335,7 @@ func TestAuthZPluginEnsureLoadImportWorking(t *testing.T) {
 	c := d.NewClientT(t)
 	ctx := context.Background()
 
-	tmp, err := ioutil.TempDir("", "test-authz-load-import")
+	tmp, err := os.MkdirTemp("", "test-authz-load-import")
 	assert.NilError(t, err)
 	defer os.RemoveAll(tmp)
 
@@ -370,11 +369,11 @@ func TestAuthzPluginEnsureContainerCopyToFrom(t *testing.T) {
 	ctrl.resRes.Allow = true
 	d.StartWithBusybox(t, "--authorization-plugin="+testAuthZPlugin, "--authorization-plugin="+testAuthZPlugin)
 
-	dir, err := ioutil.TempDir("", t.Name())
+	dir, err := os.MkdirTemp("", t.Name())
 	assert.NilError(t, err)
 	defer os.RemoveAll(dir)
 
-	f, err := ioutil.TempFile(dir, "send")
+	f, err := os.CreateTemp(dir, "send")
 	assert.NilError(t, err)
 	defer f.Close()
 
@@ -409,7 +408,7 @@ func TestAuthzPluginEnsureContainerCopyToFrom(t *testing.T) {
 
 	rdr, _, err := c.CopyFromContainer(ctx, cID, "/test")
 	assert.NilError(t, err)
-	_, err = io.Copy(ioutil.Discard, rdr)
+	_, err = io.Copy(io.Discard, rdr)
 	assert.NilError(t, err)
 }
 
diff --git a/integration/plugin/authz/authz_plugin_v2_test.go b/integration/plugin/authz/authz_plugin_v2_test.go
index f567f5a448..173d0a5df6 100644
--- a/integration/plugin/authz/authz_plugin_v2_test.go
+++ b/integration/plugin/authz/authz_plugin_v2_test.go
@@ -6,7 +6,7 @@ package authz // import "github.com/docker/docker/integration/plugin/authz"
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 	"testing"
@@ -166,6 +166,6 @@ func pluginInstallGrantAllPermissions(client client.APIClient, name string) erro
 	// we have to read the response out here because the client API
 	// actually starts a goroutine which we can only be sure has
 	// completed when we get EOF from reading responseBody
-	_, err = ioutil.ReadAll(responseReader)
+	_, err = io.ReadAll(responseReader)
 	return err
 }
diff --git a/integration/plugin/authz/main_test.go b/integration/plugin/authz/main_test.go
index ff39d61372..b4e6564081 100644
--- a/integration/plugin/authz/main_test.go
+++ b/integration/plugin/authz/main_test.go
@@ -6,7 +6,7 @@ package authz // import "github.com/docker/docker/integration/plugin/authz"
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -77,7 +77,7 @@ func setupSuite() {
 
 	mux.HandleFunc("/AuthZPlugin.AuthZReq", func(w http.ResponseWriter, r *http.Request) {
 		defer r.Body.Close()
-		body, err := ioutil.ReadAll(r.Body)
+		body, err := io.ReadAll(r.Body)
 		if err != nil {
 			panic("could not read body for /AuthZPlugin.AuthZReq: " + err.Error())
 		}
@@ -115,7 +115,7 @@ func setupSuite() {
 
 	mux.HandleFunc("/AuthZPlugin.AuthZRes", func(w http.ResponseWriter, r *http.Request) {
 		defer r.Body.Close()
-		body, err := ioutil.ReadAll(r.Body)
+		body, err := io.ReadAll(r.Body)
 		if err != nil {
 			panic("could not read body for /AuthZPlugin.AuthZRes: " + err.Error())
 		}