refactor: move from io/ioutil to io and os package (cosmos#10341)

## Description

The `io/ioutil` package has been deprecated in Go 1.16 (See https://golang.org/doc/go1.16#ioutil). Since cosmos-sdk has upgraded to Go 1.17 (cosmos#9987), this PR replaces the existing `io/ioutil` functions with their new definitions in `io` and `os` packages.

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [x] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [x] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -126,6 +126,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [\#9699](https://github.com/cosmos/cosmos-sdk/pull/9699) Add `:`, `.`, `-`, and `_` as allowed characters in the default denom regular expression.
 * (genesis) [\#9697](https://github.com/cosmos/cosmos-sdk/pull/9697) Ensure `InitGenesis` returns with non-empty validator set.
 * [\#10262](https://github.com/cosmos/cosmos-sdk/pull/10262) Remove unnecessary logging in `x/feegrant` simulation.
+* [\#10341](https://github.com/cosmos/cosmos-sdk/pull/10341) Move from `io/ioutil` to `io` and `os` packages.
 
 ### Bug Fixes
 

baseapp/baseapp_test.go

@@ -5,7 +5,6 @@ import (
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"math"
 	"math/rand"
 	"os"
@@ -162,7 +161,7 @@ func setupBaseAppWithSnapshots(t *testing.T, blocks uint, blockTxs int, options
 
 	snapshotInterval := uint64(2)
 	snapshotTimeout := 1 * time.Minute
-	snapshotDir, err := ioutil.TempDir("", "baseapp")
+	snapshotDir, err := os.MkdirTemp("", "baseapp")
 	require.NoError(t, err)
 	snapshotStore, err := snapshots.NewStore(dbm.NewMemDB(), snapshotDir)
 	require.NoError(t, err)
@@ -934,7 +933,7 @@ func incrementingCounter(t *testing.T, store sdk.KVStore, counterKey []byte, cou
 	return &sdk.Result{}, nil
 }
 
-//---------------------------------------------------------------------
+// ---------------------------------------------------------------------
 // Tx processing - CheckTx, DeliverTx, SimulateTx.
 // These tests use the serialized tx as input, while most others will use the
 // Check(), Deliver(), Simulate() methods directly.

client/config/config_test.go

@@ -3,7 +3,7 @@ package config_test
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"testing"
 
@@ -58,7 +58,7 @@ func TestConfigCmd(t *testing.T) {
 	cmd.SetOut(b)
 	cmd.SetArgs([]string{"node"})
 	cmd.Execute()
-	out, err := ioutil.ReadAll(b)
+	out, err := io.ReadAll(b)
 	require.NoError(t, err)
 	require.Equal(t, string(out), testNode1+"\n")
 }

client/config/toml.go

@@ -2,7 +2,6 @@ package config
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"text/template"
 
@@ -43,7 +42,7 @@ func writeConfigToFile(configFilePath string, config *ClientConfig) error {
 		return err
 	}
 
-	return ioutil.WriteFile(configFilePath, buffer.Bytes(), 0600)
+	return os.WriteFile(configFilePath, buffer.Bytes(), 0600)
 }
 
 // ensureConfigPath creates a directory configPath if it does not exist

client/keys/add_ledger_test.go

@@ -6,7 +6,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -188,7 +188,7 @@ func Test_runAddCmdLedgerDryRun(t *testing.T) {
 				_, err = kb.Key("testkey")
 				require.NoError(t, err)
 
-				out, err := ioutil.ReadAll(b)
+				out, err := io.ReadAll(b)
 				require.NoError(t, err)
 				require.Contains(t, string(out), "name: testkey")
 			} else {

client/keys/add_test.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -18,7 +18,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/simapp"
 	"github.com/cosmos/cosmos-sdk/testutil"
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	bip39 "github.com/cosmos/go-bip39"
+	"github.com/cosmos/go-bip39"
 )
 
 func Test_runAddCmdBasic(t *testing.T) {
@@ -220,7 +220,7 @@ func Test_runAddCmdDryRun(t *testing.T) {
 				_, err := kb.Key("testkey")
 				require.NoError(t, err)
 
-				out, err := ioutil.ReadAll(b)
+				out, err := io.ReadAll(b)
 				require.NoError(t, err)
 				require.Contains(t, string(out), "name: testkey")
 			} else {

client/keys/import.go

@@ -2,7 +2,7 @@ package keys
 
 import (
 	"bufio"
-	"io/ioutil"
+	"os"
 
 	"github.com/spf13/cobra"
 
@@ -24,7 +24,7 @@ func ImportKeyCommand() *cobra.Command {
 			}
 			buf := bufio.NewReader(clientCtx.Input)
 
-			bz, err := ioutil.ReadFile(args[1])
+			bz, err := os.ReadFile(args[1])
 			if err != nil {
 				return err
 			}

client/keys/import_test.go

@@ -3,7 +3,6 @@ package keys
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -98,7 +97,7 @@ HbP+c6JmeJy9JXe2rbbF1QtCX1gLqGcDQPBXiCtFvP7/8wTZtVOPj8vREzhZ9ElO
 
 			keyfile := filepath.Join(kbHome, "key.asc")
 
-			require.NoError(t, ioutil.WriteFile(keyfile, []byte(armoredKey), 0644))
+			require.NoError(t, os.WriteFile(keyfile, []byte(armoredKey), 0644))
 
 			defer func() {
 				_ = os.RemoveAll(kbHome)

codec/unknownproto/unknown_fields.go

@@ -5,7 +5,7 @@ import (
 	"compress/gzip"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"reflect"
 	"strings"
 	"sync"
@@ -358,7 +358,7 @@ func extractFileDescMessageDesc(desc descriptorIface) (*descriptor.FileDescripto
 	if err != nil {
 		return nil, nil, err
 	}
-	protoBlob, err := ioutil.ReadAll(gzr)
+	protoBlob, err := io.ReadAll(gzr)
 	if err != nil {
 		return nil, nil, err
 	}

container/container_test.go

@@ -2,7 +2,6 @@ package container_test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"testing"
@@ -506,14 +505,14 @@ func TestLogging(t *testing.T) {
 	var logOut string
 	var dotGraph string
 
-	outfile, err := ioutil.TempFile("", "out")
+	outfile, err := os.CreateTemp("", "out")
 	require.NoError(t, err)
 	stdout := os.Stdout
 	os.Stdout = outfile
 	defer func() { os.Stdout = stdout }()
 	defer os.Remove(outfile.Name())
 
-	graphfile, err := ioutil.TempFile("", "graph")
+	graphfile, err := os.CreateTemp("", "graph")
 	require.NoError(t, err)
 	defer os.Remove(graphfile.Name())
 
@@ -533,11 +532,11 @@ func TestLogging(t *testing.T) {
 	require.Contains(t, logOut, "digraph")
 	require.Contains(t, dotGraph, "digraph")
 
-	outfileContents, err := ioutil.ReadFile(outfile.Name())
+	outfileContents, err := os.ReadFile(outfile.Name())
 	require.NoError(t, err)
 	require.Contains(t, string(outfileContents), "digraph")
 
-	graphfileContents, err := ioutil.ReadFile(graphfile.Name())
+	graphfileContents, err := os.ReadFile(graphfile.Name())
 	require.NoError(t, err)
 	require.Contains(t, string(graphfileContents), "<svg")
 }

cosmovisor/args.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -246,7 +245,7 @@ func (cfg *Config) UpgradeInfo() UpgradeInfo {
 	if err != nil { // no current directory
 		goto returnError
 	}
-	if bz, err = ioutil.ReadFile(filename); err != nil {
+	if bz, err = os.ReadFile(filename); err != nil {
 		goto returnError
 	}
 	if err = json.Unmarshal(bz, &u); err != nil {

cosmovisor/process.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -113,7 +112,7 @@ func doBackup(cfg *Config) error {
 	if !cfg.UnsafeSkipBackup {
 		// check if upgrade-info.json is not empty.
 		var uInfo UpgradeInfo
-		upgradeInfoFile, err := ioutil.ReadFile(filepath.Join(cfg.Home, "data", "upgrade-info.json"))
+		upgradeInfoFile, err := os.ReadFile(filepath.Join(cfg.Home, "data", "upgrade-info.json"))
 		if err != nil {
 			return fmt.Errorf("error while reading upgrade-info.json: %w", err)
 		}

cosmovisor/upgrade.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -108,7 +107,7 @@ func GetDownloadURL(info UpgradeInfo) (string, error) {
 	doc := strings.TrimSpace(info.Info)
 	// if this is a url, then we download that and try to get a new doc with the real info
 	if _, err := url.Parse(doc); err == nil {
-		tmpDir, err := ioutil.TempDir("", "upgrade-manager-reference")
+		tmpDir, err := os.MkdirTemp("", "upgrade-manager-reference")
 		if err != nil {
 			return "", fmt.Errorf("create tempdir for reference file: %w", err)
 		}
@@ -119,7 +118,7 @@ func GetDownloadURL(info UpgradeInfo) (string, error) {
 			return "", fmt.Errorf("downloading reference link %s: %w", doc, err)
 		}
 
-		refBytes, err := ioutil.ReadFile(refPath)
+		refBytes, err := os.ReadFile(refPath)
 		if err != nil {
 			return "", fmt.Errorf("reading downloaded reference: %w", err)
 		}

crypto/hd/fundraiser_test.go

@@ -4,7 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -35,7 +35,7 @@ func initFundraiserTestVectors(t *testing.T) []addrData {
 	// var hdPath string = "m/44'/118'/0'/0/0"
 	var hdToAddrTable []addrData
 
-	b, err := ioutil.ReadFile("testdata/test.json")
+	b, err := os.ReadFile("testdata/test.json")
 	if err != nil {
 		t.Fatalf("could not read fundraiser test vector file (testdata/test.json): %s", err)
 	}

crypto/keyring/keyring.go

@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -682,7 +681,7 @@ func newRealPrompt(dir string, buf io.Reader) func(string) (string, error) {
 
 		switch {
 		case err == nil:
-			keyhash, err = ioutil.ReadFile(keyhashFilePath)
+			keyhash, err = os.ReadFile(keyhashFilePath)
 			if err != nil {
 				return "", fmt.Errorf("failed to read %s: %v", keyhashFilePath, err)
 			}
@@ -746,7 +745,7 @@ func newRealPrompt(dir string, buf io.Reader) func(string) (string, error) {
 				continue
 			}
 
-			if err := ioutil.WriteFile(dir+"/keyhash", passwordHash, 0555); err != nil {
+			if err := os.WriteFile(dir+"/keyhash", passwordHash, 0555); err != nil {
 				return "", err
 			}
 

server/export.go

@@ -4,7 +4,6 @@ package server
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	"github.com/spf13/cobra"
@@ -49,7 +48,7 @@ func ExportCmd(appExporter types.AppExporter, defaultNodeHome string) *cobra.Com
 					return err
 				}
 
-				genesis, err := ioutil.ReadFile(config.GenesisFile())
+				genesis, err := os.ReadFile(config.GenesisFile())
 				if err != nil {
 					return err
 				}

server/grpc/gogoreflection/serverreflection.go

@@ -41,7 +41,6 @@ import (
 	"compress/gzip"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"reflect"
 	"sort"
@@ -219,7 +218,7 @@ func decompress(b []byte) ([]byte, error) {
 	if err != nil {
 		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
 	}
-	out, err := ioutil.ReadAll(r)
+	out, err := io.ReadAll(r)
 	if err != nil {
 		return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
 	}

server/grpc/grpc_web_test.go

@@ -7,7 +7,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/textproto"
 	"strconv"
@@ -197,7 +196,7 @@ func (s *GRPCWebTestSuite) makeGrpcRequest(
 		return nil, Trailer{}, nil, err
 	}
 	defer resp.Body.Close()
-	contents, err := ioutil.ReadAll(resp.Body)
+	contents, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, Trailer{}, nil, err
 	}

server/mock/helpers.go

@@ -2,7 +2,6 @@ package mock
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -14,7 +13,7 @@ import (
 func SetupApp() (abci.Application, func(), error) {
 	logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout)).
 		With("module", "mock")
-	rootDir, err := ioutil.TempDir("", "mock-sdk")
+	rootDir, err := os.MkdirTemp("", "mock-sdk")
 	if err != nil {
 		return nil, nil, err
 	}