ioutil: remove most references to ioutil

This change removes most references to `ioutil` and replaces them with
equivalent methods in `io` and `os`. All of the changes in this PR were
made by the attached script. The script was used to migrate the
cockroach cloud repository.

The script does not migrate `ioutil.ReadDir` to os.ReadDir. os.ReadDir has a
different type and is not a drop in replacement.

```bash
function rewrite {
    fastmod -F "${1?}" "${2?}" -g '!vendor/' -g '*go'
}

rewrite ioutil.ReadAll io.ReadAll
rewrite ioutil.ReadFile os.ReadFile
rewrite ioutil.TempDir os.MkdirTemp
rewrite ioutil.TempFile os.CreateTemp
rewrite ioutil.WriteFile os.WriteFile

goimports -w .
```

Release justification: required by go1.19 linter
Release note: None

build/bazelutil/unused_checker/unused_checker.go

@@ -24,7 +24,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -74,7 +73,7 @@ func impl() error {
 		if output, err := cmd.CombinedOutput(); err != nil {
 			return fmt.Errorf("%w (got output %s while processing file %s)", err, string(output), nogoX)
 		}
-		encoded, err := ioutil.ReadFile(filepath.Join(tmpdir, "unused.out"))
+		encoded, err := os.ReadFile(filepath.Join(tmpdir, "unused.out"))
 		if err != nil {
 			return err
 		}
@@ -92,7 +91,7 @@ func impl() error {
 	var failures []string
 	for pkgPath, objs := range unused {
 		usedPkgMap := used[pkgPath]
-		for obj, _ := range objs {
+		for obj := range objs {
 			_, ok := usedPkgMap[obj]
 			if !ok {
 				failure := fmt.Sprintf("%s.%s", pkgPath, obj)

pkg/acceptance/cluster/dockercluster.go

@@ -164,7 +164,7 @@ func CreateDocker(
 	clusterIDS := clusterID.Short()
 
 	if volumesDir == "" {
-		volumesDir, err = ioutil.TempDir("", fmt.Sprintf("cockroach-acceptance-%s", clusterIDS))
+		volumesDir, err = os.MkdirTemp("", fmt.Sprintf("cockroach-acceptance-%s", clusterIDS))
 		maybePanic(err)
 	} else {
 		volumesDir = filepath.Join(volumesDir, clusterIDS)

pkg/acceptance/localcluster/cluster.go

@@ -17,7 +17,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"net"
 	"net/url"
@@ -664,7 +663,7 @@ func (n *Node) httpAddrFile() string {
 }
 
 func readFileOrEmpty(f string) string {
-	c, err := ioutil.ReadFile(f)
+	c, err := os.ReadFile(f)
 	if err != nil {
 		if !oserror.IsNotExist(err) {
 			panic(err)
@@ -710,7 +709,7 @@ func (n *Node) waitUntilLive(dur time.Duration) error {
 			return nil
 		}
 
-		urlBytes, err := ioutil.ReadFile(n.listeningURLFile())
+		urlBytes, err := os.ReadFile(n.listeningURLFile())
 		if err != nil {
 			log.Infof(ctx, "%v", err)
 			continue

pkg/acceptance/util_docker.go

@@ -13,7 +13,6 @@ package acceptance
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -90,7 +89,7 @@ func testDocker(
 		}
 		testdataDir := filepath.Join(pwd, "testdata")
 		if bazel.BuiltWithBazel() {
-			testdataDir, err = ioutil.TempDir("", "")
+			testdataDir, err = os.MkdirTemp("", "")
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -108,7 +107,7 @@ func testDocker(
 			Binds:       []string{testdataDir + ":/mnt/data"},
 		}
 		if bazel.BuiltWithBazel() {
-			interactivetestsDir, err := ioutil.TempDir("", "")
+			interactivetestsDir, err := os.MkdirTemp("", "")
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -149,11 +148,11 @@ func copyRunfiles(source, destination string) error {
 		if dirEntry.IsDir() {
 			return os.Mkdir(filepath.Join(destination, relPath), 0755)
 		}
-		data, err := ioutil.ReadFile(filepath.Join(source, relPath))
+		data, err := os.ReadFile(filepath.Join(source, relPath))
 		if err != nil {
 			return err
 		}
-		return ioutil.WriteFile(filepath.Join(destination, relPath), data, 0755)
+		return os.WriteFile(filepath.Join(destination, relPath), data, 0755)
 	})
 }
 

pkg/base/store_spec.go

@@ -13,8 +13,8 @@ package base
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"net"
+	"os"
 	"path/filepath"
 	"regexp"
 	"sort"
@@ -483,7 +483,7 @@ func (ssl StoreSpecList) PriorCriticalAlertError() (err error) {
 		if path == "" {
 			continue
 		}
-		b, err := ioutil.ReadFile(path)
+		b, err := os.ReadFile(path)
 		if err != nil {
 			if !oserror.IsNotExist(err) {
 				addError(errors.Wrapf(err, "%s", path))

pkg/base/store_spec_test.go

@@ -12,7 +12,6 @@ package base_test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -287,7 +286,7 @@ func TestStoreSpecListPreventedStartupMessage(t *testing.T) {
 	err := ssl.PriorCriticalAlertError()
 	require.NoError(t, err)
 
-	require.NoError(t, ioutil.WriteFile(ssl.Specs[2].PreventedStartupFile(), []byte("boom"), 0644))
+	require.NoError(t, os.WriteFile(ssl.Specs[2].PreventedStartupFile(), []byte("boom"), 0644))
 
 	err = ssl.PriorCriticalAlertError()
 	require.Error(t, err)

pkg/bench/rttanalysis/rtt_analysis_bench.go

@@ -12,7 +12,7 @@ package rttanalysis
 
 import (
 	"context"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -177,7 +177,7 @@ func executeRoundTripTest(b testingB, tc RoundTripBenchTestCase, cc ClusterConst
 		jaegerJSON, err := r.ToJaegerJSON(tc.Stmt, "", "n0")
 		require.NoError(b, err)
 		path := filepath.Join(dir, strings.Replace(b.Name(), "/", "_", -1)) + ".jaeger.json"
-		require.NoError(b, ioutil.WriteFile(path, []byte(jaegerJSON), 0666))
+		require.NoError(b, os.WriteFile(path, []byte(jaegerJSON), 0666))
 		b.Errorf("wrote jaeger trace to %s", path)
 	}
 	b.ReportMetric(res, roundTripsMetric)

pkg/bench/tpcc/tpcc_bench_test.go

@@ -18,7 +18,7 @@ package tpcc
 
 import (
 	"context"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
@@ -185,7 +185,7 @@ type event struct {
 }
 
 func (bm *benchmark) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	data, err := ioutil.ReadAll(r.Body)
+	data, err := io.ReadAll(r.Body)
 	if err != nil {
 		bm.addEvent(err.Error())
 		w.WriteHeader(500)

pkg/blobs/bench_test.go

@@ -14,7 +14,6 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -48,7 +47,7 @@ func writeLargeFile(t testing.TB, file string, size int64) {
 		t.Fatal(err)
 	}
 	content := make([]byte, size)
-	err = ioutil.WriteFile(file, content, 0600)
+	err = os.WriteFile(file, content, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/blobs/client_test.go

@@ -14,7 +14,6 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
@@ -102,7 +101,7 @@ func writeTestFile(t testing.TB, file string, content []byte) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ioutil.WriteFile(file, content, 0600)
+	err = os.WriteFile(file, content, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -273,7 +272,7 @@ func TestBlobClientWriteFile(t *testing.T) {
 				t.Fatal(err)
 			}
 			// Check that file is now in correct node
-			content, err := ioutil.ReadFile(filepath.Join(tc.destinationNodeDir, tc.filename))
+			content, err := os.ReadFile(filepath.Join(tc.destinationNodeDir, tc.filename))
 			if err != nil {
 				t.Fatal(err, "unable to read fetched file")
 			}
@@ -469,7 +468,7 @@ func TestBlobClientDeleteFrom(t *testing.T) {
 				t.Fatal(err)
 			}
 
-			_, err = ioutil.ReadFile(filepath.Join(localExternalDir, tc.filename))
+			_, err = os.ReadFile(filepath.Join(localExternalDir, tc.filename))
 			if err == nil {
 				t.Fatal(err, "file should have been deleted")
 			}

pkg/blobs/local_storage.go

@@ -13,7 +13,6 @@ package blobs
 import (
 	"context"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -122,9 +121,9 @@ func (l *LocalStorage) Writer(ctx context.Context, filename string) (io.WriteClo
 	// - it avoids a cross-filesystem rename in the common case.
 	//   (There can still be cross-filesystem renames in very
 	//   exotic edge cases, hence the use fileutil.Move below.)
-	// See the explanatory comment for ioutil.TempFile to understand
+	// See the explanatory comment for os.CreateTemp to understand
 	// what the "*" in the suffix means.
-	tmpFile, err := ioutil.TempFile(targetDir, filepath.Base(fullPath)+"*.tmp")
+	tmpFile, err := os.CreateTemp(targetDir, filepath.Base(fullPath)+"*.tmp")
 	if err != nil {
 		return nil, errors.Wrap(err, "creating temporary file")
 	}

pkg/ccl/backupccl/backup_test.go

@@ -140,7 +140,7 @@ func TestBackupRestoreStatementResult(t *testing.T) {
 	t.Run("GZipBackupManifest", func(t *testing.T) {
 		backupDir := fmt.Sprintf("%s/foo", dir)
 		backupManifestFile := backupDir + "/" + backupbase.BackupManifestName
-		backupManifestBytes, err := ioutil.ReadFile(backupManifestFile)
+		backupManifestBytes, err := os.ReadFile(backupManifestFile)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -297,7 +297,7 @@ func TestBackupRestorePartitioned(t *testing.T) {
 				fName := f.Name()
 				if partitionMatcher.MatchString(fName) {
 					backupPartitionFile := subDir + "/" + fName
-					backupPartitionBytes, err := ioutil.ReadFile(backupPartitionFile)
+					backupPartitionBytes, err := os.ReadFile(backupPartitionFile)
 					if err != nil {
 						t.Fatal(err)
 					}
@@ -1589,7 +1589,7 @@ func TestBackupRestoreResume(t *testing.T) {
 					t.Fatal(err)
 				}
 				checkpointFile := backupDir + item.checkpointDirectory + "/" + backupinfo.BackupManifestCheckpointName
-				if err := ioutil.WriteFile(checkpointFile, mockManifest, 0644); err != nil {
+				if err := os.WriteFile(checkpointFile, mockManifest, 0644); err != nil {
 					t.Fatal(err)
 				}
 				createAndWaitForJob(
@@ -1604,7 +1604,7 @@ func TestBackupRestoreResume(t *testing.T) {
 				// If the backup properly took the (incorrect) checkpoint into account, it
 				// won't have tried to re-export any keys within backupCompletedSpan.
 				backupManifestFile := backupDir + "/" + backupbase.BackupManifestName
-				backupManifestBytes, err := ioutil.ReadFile(backupManifestFile)
+				backupManifestBytes, err := os.ReadFile(backupManifestFile)
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -3952,7 +3952,7 @@ func TestBackupRestoreChecksum(t *testing.T) {
 
 	var backupManifest backuppb.BackupManifest
 	{
-		backupManifestBytes, err := ioutil.ReadFile(filepath.Join(dir, backupbase.BackupManifestName))
+		backupManifestBytes, err := os.ReadFile(filepath.Join(dir, backupbase.BackupManifestName))
 		if err != nil {
 			t.Fatalf("%+v", err)
 		}
@@ -4110,7 +4110,7 @@ func checkBackupStatsEncrypted(t *testing.T, rawDir string) {
 			return err
 		}
 		if partitionMatcher.MatchString(fName) {
-			statsBytes, err := ioutil.ReadFile(fName)
+			statsBytes, err := os.ReadFile(fName)
 			if err != nil {
 				return err
 			}
@@ -4129,7 +4129,7 @@ func checkBackupFilesEncrypted(t *testing.T, rawDir string) {
 	checkedFiles := 0
 	if err := filepath.Walk(rawDir, func(path string, info os.FileInfo, err error) error {
 		if !info.IsDir() && !strings.Contains(path, "foo/cleartext") {
-			data, err := ioutil.ReadFile(path)
+			data, err := os.ReadFile(path)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -8220,7 +8220,7 @@ func TestManifestTooNew(t *testing.T) {
 
 	// Load/deserialize the manifest so we can mess with it.
 	manifestPath := filepath.Join(rawDir, "too_new", backupbase.BackupManifestName)
-	manifestData, err := ioutil.ReadFile(manifestPath)
+	manifestData, err := os.ReadFile(manifestPath)
 	require.NoError(t, err)
 	manifestData, err = backupinfo.DecompressData(context.Background(), nil, manifestData)
 	require.NoError(t, err)
@@ -8231,11 +8231,11 @@ func TestManifestTooNew(t *testing.T) {
 	backupManifest.ClusterVersion = roachpb.Version{Major: 99, Minor: 1}
 	manifestData, err = protoutil.Marshal(&backupManifest)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath, manifestData, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath, manifestData, 0644 /* perm */))
 	// Also write the checksum file to match the new manifest.
 	checksum, err := backupinfo.GetChecksum(manifestData)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
 
 	// Verify we reject it.
 	sqlDB.ExpectErr(t, "backup from version 99.1 is newer than current version", `RESTORE DATABASE r1 FROM 'nodelocal://0/too_new'`)
@@ -8244,11 +8244,11 @@ func TestManifestTooNew(t *testing.T) {
 	backupManifest.ClusterVersion = roachpb.Version{Major: 20, Minor: 2, Internal: 2}
 	manifestData, err = protoutil.Marshal(&backupManifest)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath, manifestData, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath, manifestData, 0644 /* perm */))
 	// Also write the checksum file to match the new manifest.
 	checksum, err = backupinfo.GetChecksum(manifestData)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
 
 	// Prove we can restore again.
 	sqlDB.Exec(t, `RESTORE DATABASE r1 FROM 'nodelocal://0/too_new'`)
@@ -8258,11 +8258,11 @@ func TestManifestTooNew(t *testing.T) {
 	backupManifest.ClusterVersion = roachpb.Version{}
 	manifestData, err = protoutil.Marshal(&backupManifest)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath, manifestData, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath, manifestData, 0644 /* perm */))
 	// Also write the checksum file to match the new manifest.
 	checksum, err = backupinfo.GetChecksum(manifestData)
 	require.NoError(t, err)
-	require.NoError(t, ioutil.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
+	require.NoError(t, os.WriteFile(manifestPath+backupinfo.BackupManifestChecksumSuffix, checksum, 0644 /* perm */))
 	// Prove we can restore again.
 	sqlDB.Exec(t, `RESTORE DATABASE r1 FROM 'nodelocal://0/too_new'`)
 	sqlDB.Exec(t, `DROP DATABASE r1`)
@@ -8303,10 +8303,10 @@ func flipBitInManifests(t *testing.T, rawDir string) {
 		log.Infof(context.Background(), "visiting %s", path)
 		if filepath.Base(path) == backupbase.BackupManifestName {
 			foundManifest = true
-			data, err := ioutil.ReadFile(path)
+			data, err := os.ReadFile(path)
 			require.NoError(t, err)
 			data[20] ^= 1
-			if err := ioutil.WriteFile(path, data, 0644 /* perm */); err != nil {
+			if err := os.WriteFile(path, data, 0644 /* perm */); err != nil {
 				t.Fatal(err)
 			}
 		}
@@ -10221,7 +10221,7 @@ func TestBackupDoNotIncludeViewSpans(t *testing.T) {
 	// Read the backup manifest.
 	var backupManifest backuppb.BackupManifest
 	{
-		backupManifestBytes, err := ioutil.ReadFile(filepath.Join(dir, "foo", res[0][0], backupbase.BackupManifestName))
+		backupManifestBytes, err := os.ReadFile(filepath.Join(dir, "foo", res[0][0], backupbase.BackupManifestName))
 		if err != nil {
 			t.Fatalf("%+v", err)
 		}