all: Remove usage of deprecated io/ioutil (syncthing#7971)

As of Go 1.16 io/ioutil is deprecated. This replaces usage with the
corresponding functions in package os and package io.

build.go

@@ -20,7 +20,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -723,7 +722,7 @@ func shouldBuildSyso(dir string) (string, error) {
 	}
 
 	jsonPath := filepath.Join(dir, "versioninfo.json")
-	err = ioutil.WriteFile(jsonPath, bs, 0644)
+	err = os.WriteFile(jsonPath, bs, 0644)
 	if err != nil {
 		return "", errors.New("failed to create " + jsonPath + ": " + err.Error())
 	}
@@ -762,12 +761,12 @@ func shouldCleanupSyso(sysoFilePath string) {
 // exists. The permission bits are copied as well. If dst already exists and
 // the contents are identical to src the modification time is not updated.
 func copyFile(src, dst string, perm os.FileMode) error {
-	in, err := ioutil.ReadFile(src)
+	in, err := os.ReadFile(src)
 	if err != nil {
 		return err
 	}
 
-	out, err := ioutil.ReadFile(dst)
+	out, err := os.ReadFile(dst)
 	if err != nil {
 		// The destination probably doesn't exist, we should create
 		// it.
@@ -783,7 +782,7 @@ func copyFile(src, dst string, perm os.FileMode) error {
 
 copy:
 	os.MkdirAll(filepath.Dir(dst), 0777)
-	if err := ioutil.WriteFile(dst, in, perm); err != nil {
+	if err := os.WriteFile(dst, in, perm); err != nil {
 		return err
 	}
 
@@ -958,7 +957,7 @@ func rmr(paths ...string) {
 }
 
 func getReleaseVersion() (string, error) {
-	bs, err := ioutil.ReadFile("RELEASE")
+	bs, err := os.ReadFile("RELEASE")
 	if err != nil {
 		return "", err
 	}
@@ -1290,7 +1289,7 @@ func zipFile(out string, files []archiveFile) {
 
 		if strings.HasSuffix(f.dst, ".txt") {
 			// Text file. Read it and convert line endings.
-			bs, err := ioutil.ReadAll(sf)
+			bs, err := io.ReadAll(sf)
 			if err != nil {
 				log.Fatal(err)
 			}

cmd/stcrashreceiver/main.go

@@ -17,7 +17,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -58,7 +57,7 @@ func main() {
 func handleFailureFn(dsn, failureDir string) func(w http.ResponseWriter, req *http.Request) {
 	return func(w http.ResponseWriter, req *http.Request) {
 		lr := io.LimitReader(req.Body, maxRequestSize)
-		bs, err := ioutil.ReadAll(lr)
+		bs, err := io.ReadAll(lr)
 		req.Body.Close()
 		if err != nil {
 			http.Error(w, err.Error(), 500)

cmd/stcrashreceiver/sentry.go

@@ -9,7 +9,7 @@ package main
 import (
 	"bytes"
 	"errors"
-	"io/ioutil"
+	"io"
 	"regexp"
 	"strings"
 	"sync"
@@ -93,7 +93,7 @@ func parseCrashReport(path string, report []byte) (*raven.Packet, error) {
 	}
 
 	r := bytes.NewReader(report)
-	ctx, err := stack.ParseDump(r, ioutil.Discard, false)
+	ctx, err := stack.ParseDump(r, io.Discard, false)
 	if err != nil {
 		return nil, err
 	}

cmd/stcrashreceiver/sentry_test.go

@@ -8,7 +8,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"testing"
 )
 
@@ -59,7 +59,7 @@ func TestParseVersion(t *testing.T) {
 }
 
 func TestParseReport(t *testing.T) {
-	bs, err := ioutil.ReadFile("_testdata/panic.log")
+	bs, err := os.ReadFile("_testdata/panic.log")
 	if err != nil {
 		t.Fatal(err)
 	}

cmd/stcrashreceiver/sourcecodeloader.go

@@ -9,7 +9,7 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"path/filepath"
 	"strings"
@@ -80,7 +80,7 @@ func (l *githubSourceCodeLoader) Load(filename string, line, context int) ([][]b
 			fmt.Println("Loading source:", resp.Status)
 			return nil, 0
 		}
-		data, err := ioutil.ReadAll(resp.Body)
+		data, err := io.ReadAll(resp.Body)
 		_ = resp.Body.Close()
 		if err != nil {
 			fmt.Println("Loading source:", err.Error())

cmd/stcrashreceiver/stcrashreceiver.go

@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"compress/gzip"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -96,7 +95,7 @@ func (r *crashReceiver) servePut(reportID, fullPath string, w http.ResponseWrite
 	// Read at most maxRequestSize of report data.
 	log.Println("Receiving report", reportID)
 	lr := io.LimitReader(req.Body, maxRequestSize)
-	bs, err := ioutil.ReadAll(lr)
+	bs, err := io.ReadAll(lr)
 	if err != nil {
 		log.Println("Reading report:", err)
 		http.Error(w, "Internal server error", http.StatusInternalServerError)
@@ -110,7 +109,7 @@ func (r *crashReceiver) servePut(reportID, fullPath string, w http.ResponseWrite
 	gw.Close()
 
 	// Create an output file with the compressed report
-	err = ioutil.WriteFile(fullPath, buf.Bytes(), 0644)
+	err = os.WriteFile(fullPath, buf.Bytes(), 0644)
 	if err != nil {
 		log.Println("Saving report:", err)
 		http.Error(w, "Internal server error", http.StatusInternalServerError)

cmd/stcrashreceiver/util.go

@@ -10,9 +10,9 @@ import (
 	"bytes"
 	"compress/gzip"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"net/http"
+	"os"
 	"path/filepath"
 	"time"
 
@@ -53,5 +53,5 @@ func compressAndWrite(bs []byte, fullPath string) error {
 	gw.Close()
 
 	// Create an output file with the compressed report
-	return ioutil.WriteFile(fullPath, buf.Bytes(), 0644)
+	return os.WriteFile(fullPath, buf.Bytes(), 0644)
 }

cmd/strelaypoolsrv/main.go

@@ -11,7 +11,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
@@ -560,7 +559,7 @@ func limit(addr string, cache *lru.Cache, lock sync.Mutex, intv time.Duration, b
 }
 
 func loadRelays(file string) []*relay {
-	content, err := ioutil.ReadFile(file)
+	content, err := os.ReadFile(file)
 	if err != nil {
 		log.Println("Failed to load relays: " + err.Error())
 		return nil
@@ -598,11 +597,11 @@ func saveRelays(file string, relays []*relay) error {
 	for _, relay := range relays {
 		content += relay.uri.String() + "\n"
 	}
-	return ioutil.WriteFile(file, []byte(content), 0777)
+	return os.WriteFile(file, []byte(content), 0777)
 }
 
 func createTestCertificate() tls.Certificate {
-	tmpDir, err := ioutil.TempDir("", "relaypoolsrv")
+	tmpDir, err := os.MkdirTemp("", "relaypoolsrv")
 	if err != nil {
 		log.Fatal(err)
 	}

cmd/strelaysrv/pool.go

@@ -6,7 +6,7 @@ import (
 	"bytes"
 	"crypto/tls"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/url"
@@ -56,7 +56,7 @@ func poolHandler(pool string, uri *url.URL, mapping mapping, ownCert tls.Certifi
 			continue
 		}
 
-		bs, err := ioutil.ReadAll(resp.Body)
+		bs, err := io.ReadAll(resp.Body)
 		resp.Body.Close()
 		if err != nil {
 			log.Printf("Error joining pool %v: reading response: %v", pool, err)

cmd/stsigtool/main.go

@@ -9,7 +9,6 @@ package main
 import (
 	"flag"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 
@@ -69,7 +68,7 @@ func gen() {
 }
 
 func sign(keyname, dataname string) {
-	privkey, err := ioutil.ReadFile(keyname)
+	privkey, err := os.ReadFile(keyname)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -95,15 +94,15 @@ func sign(keyname, dataname string) {
 }
 
 func verifyWithFile(signame, dataname, keyname string) {
-	pubkey, err := ioutil.ReadFile(keyname)
+	pubkey, err := os.ReadFile(keyname)
 	if err != nil {
 		log.Fatal(err)
 	}
 	verifyWithKey(signame, dataname, pubkey)
 }
 
 func verifyWithKey(signame, dataname string, pubkey []byte) {
-	sig, err := ioutil.ReadFile(signame)
+	sig, err := os.ReadFile(signame)
 	if err != nil {
 		log.Fatal(err)
 	}

cmd/syncthing/cli/main.go

@@ -9,7 +9,7 @@ package cli
 import (
 	"bufio"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 
@@ -151,7 +151,7 @@ func parseFlags(c *preCli) error {
 		}
 	}
 	// We don't want kong to print anything nor os.Exit (e.g. on -h)
-	parser, err := kong.New(c, kong.Writers(ioutil.Discard, ioutil.Discard), kong.Exit(func(int) {}))
+	parser, err := kong.New(c, kong.Writers(io.Discard, io.Discard), kong.Exit(func(int) {}))
 	if err != nil {
 		return err
 	}

cmd/syncthing/cli/utils.go

@@ -10,7 +10,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"mime"
 	"net/http"
 	"os"
@@ -23,7 +23,7 @@ import (
 )
 
 func responseToBArray(response *http.Response) ([]byte, error) {
-	bytes, err := ioutil.ReadAll(response.Body)
+	bytes, err := io.ReadAll(response.Body)
 	if err != nil {
 		return nil, err
 	}

cmd/syncthing/crash_reporting.go

@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -62,7 +61,7 @@ func uploadPanicLogs(ctx context.Context, urlBase, dir string) {
 // the log contents. A HEAD request is made to see if the log has already
 // been reported. If not, a PUT is made with the log contents.
 func uploadPanicLog(ctx context.Context, urlBase, file string) error {
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return err
 	}

cmd/syncthing/decrypt/decrypt.go

@@ -12,8 +12,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
+	"os"
 	"path/filepath"
 
 	"github.com/syncthing/syncthing/lib/config"
@@ -112,7 +112,7 @@ func (c *CLI) withContinue(err error) error {
 // error.
 func (c *CLI) getFolderID() (string, error) {
 	tokenPath := filepath.Join(c.Path, c.TokenPath)
-	bs, err := ioutil.ReadFile(tokenPath)
+	bs, err := os.ReadFile(tokenPath)
 	if err != nil {
 		return "", fmt.Errorf("reading folder token: %w", err)
 	}

cmd/syncthing/main.go

@@ -12,7 +12,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/http"
 	_ "net/http/pprof" // Need to import this to support STPROFILER.
@@ -500,7 +499,7 @@ func upgradeViaRest() error {
 		return err
 	}
 	if resp.StatusCode != 200 {
-		bs, err := ioutil.ReadAll(resp.Body)
+		bs, err := io.ReadAll(resp.Body)
 		defer resp.Body.Close()
 		if err != nil {
 			return err

cmd/syncthing/monitor_test.go

@@ -8,7 +8,6 @@ package main
 
 import (
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -18,7 +17,7 @@ import (
 func TestRotatedFile(t *testing.T) {
 	// Verify that log rotation happens.
 
-	dir, err := ioutil.TempDir("", "syncthing")
+	dir, err := os.MkdirTemp("", "syncthing")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -179,7 +178,7 @@ func TestAutoClosedFile(t *testing.T) {
 	}
 
 	// The file should have both writes in it.
-	bs, err := ioutil.ReadFile(file)
+	bs, err := os.ReadFile(file)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -199,7 +198,7 @@ func TestAutoClosedFile(t *testing.T) {
 	}
 
 	// It should now contain three writes, as the file is always opened for appending
-	bs, err = ioutil.ReadFile(file)
+	bs, err = os.ReadFile(file)
 	if err != nil {
 		t.Fatal(err)
 	}