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 <[email protected]>

builder/builder-next/adapters/containerimage/pull.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"path"
 	"runtime"
 	"sync"
@@ -640,7 +639,7 @@ func (ld *layerDescriptor) Download(ctx context.Context, progressOutput pkgprogr
 		return nil, 0, err
 	}
 
-	return ioutil.NopCloser(content.NewReader(ra)), ld.desc.Size, nil
+	return io.NopCloser(content.NewReader(ra)), ld.desc.Size, nil
 }
 
 func (ld *layerDescriptor) Close() {

builder/builder-next/executor_unix.go

@@ -4,7 +4,6 @@
 package buildkit
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -35,7 +34,7 @@ func newExecutor(root, cgroupParent string, net libnetwork.NetworkController, dn
 	}
 
 	// make sure net state directory is cleared from previous state
-	fis, err := ioutil.ReadDir(netRoot)
+	fis, err := os.ReadDir(netRoot)
 	if err == nil {
 		for _, fi := range fis {
 			fp := filepath.Join(netRoot, fi.Name())

builder/builder-next/worker/worker.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	nethttp "net/http"
 	"runtime"
 	"strings"
@@ -445,7 +444,7 @@ func (ld *layerDescriptor) Download(ctx context.Context, progressOutput pkgprogr
 		return nil, 0, err
 	}
 
-	return ioutil.NopCloser(content.NewReader(ra)), ld.desc.Size, nil
+	return io.NopCloser(content.NewReader(ra)), ld.desc.Size, nil
 }
 
 func (ld *layerDescriptor) Close() {

builder/dockerfile/builder.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"sort"
 	"strings"
 
@@ -346,8 +345,8 @@ func BuildFromConfig(config *container.Config, changes []string, os string) (*co
 		}
 	}
 
-	b.Stdout = ioutil.Discard
-	b.Stderr = ioutil.Discard
+	b.Stdout = io.Discard
+	b.Stderr = io.Discard
 	b.disableCommit = true
 
 	var commands []instructions.Command

builder/dockerfile/utils_test.go

@@ -1,7 +1,6 @@
 package dockerfile // import "github.com/docker/docker/builder/dockerfile"
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -11,7 +10,7 @@ import (
 // It returns the created path and a cleanup function which is meant to be used as deferred call.
 // When an error occurs, it terminates the test.
 func createTestTempDir(t *testing.T, dir, prefix string) (string, func()) {
-	path, err := ioutil.TempDir(dir, prefix)
+	path, err := os.MkdirTemp(dir, prefix)
 
 	if err != nil {
 		t.Fatalf("Error when creating directory %s with prefix %s: %s", dir, prefix, err)
@@ -30,7 +29,7 @@ func createTestTempDir(t *testing.T, dir, prefix string) (string, func()) {
 // When an error occurs, it terminates the test
 func createTestTempFile(t *testing.T, dir, filename, contents string, perm os.FileMode) string {
 	filePath := filepath.Join(dir, filename)
-	err := ioutil.WriteFile(filePath, []byte(contents), perm)
+	err := os.WriteFile(filePath, []byte(contents), perm)
 
 	if err != nil {
 		t.Fatalf("Error when creating %s file: %s", filename, err)

builder/remotecontext/detect_test.go

@@ -2,7 +2,6 @@ package remotecontext // import "github.com/docker/docker/builder/remotecontext"
 
 import (
 	"errors"
-	"io/ioutil"
 	"log"
 	"os"
 	"sort"
@@ -20,7 +19,7 @@ const (
 
 const shouldStayFilename = "should_stay"
 
-func extractFilenames(files []os.FileInfo) []string {
+func extractFilenames(files []os.DirEntry) []string {
 	filenames := make([]string, len(files))
 
 	for i, file := range files {
@@ -31,7 +30,7 @@ func extractFilenames(files []os.FileInfo) []string {
 }
 
 func checkDirectory(t *testing.T, dir string, expectedFiles []string) {
-	files, err := ioutil.ReadDir(dir)
+	files, err := os.ReadDir(dir)
 
 	if err != nil {
 		t.Fatalf("Could not read directory: %s", err)

builder/remotecontext/git/gitutils.go

@@ -1,7 +1,6 @@
 package git // import "github.com/docker/docker/builder/remotecontext/git"
 
 import (
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"os"
@@ -34,7 +33,7 @@ func Clone(remoteURL string) (string, error) {
 func cloneGitRepo(repo gitRepo) (checkoutDir string, err error) {
 	fetch := fetchArgs(repo.remote, repo.ref)
 
-	root, err := ioutil.TempDir("", "docker-build-git")
+	root, err := os.MkdirTemp("", "docker-build-git")
 	if err != nil {
 		return "", err
 	}

builder/remotecontext/git/gitutils_test.go

@@ -2,7 +2,6 @@ package git // import "github.com/docker/docker/builder/remotecontext/git"
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -171,7 +170,7 @@ func gitGetConfig(name string) string {
 }
 
 func TestCheckoutGit(t *testing.T) {
-	root, err := ioutil.TempDir("", "docker-build-git-checkout")
+	root, err := os.MkdirTemp("", "docker-build-git-checkout")
 	assert.NilError(t, err)
 	defer os.RemoveAll(root)
 
@@ -195,13 +194,13 @@ func TestCheckoutGit(t *testing.T) {
 	_, err = gitWithinDir(gitDir, "config", "user.name", "Docker test")
 	assert.NilError(t, err)
 
-	err = ioutil.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch"), 0644)
+	err = os.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch"), 0644)
 	assert.NilError(t, err)
 
 	subDir := filepath.Join(gitDir, "subdir")
 	assert.NilError(t, os.Mkdir(subDir, 0755))
 
-	err = ioutil.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 5000"), 0644)
+	err = os.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 5000"), 0644)
 	assert.NilError(t, err)
 
 	if runtime.GOOS != "windows" {
@@ -223,10 +222,10 @@ func TestCheckoutGit(t *testing.T) {
 	_, err = gitWithinDir(gitDir, "checkout", "-b", "test")
 	assert.NilError(t, err)
 
-	err = ioutil.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 3000"), 0644)
+	err = os.WriteFile(filepath.Join(gitDir, "Dockerfile"), []byte("FROM scratch\nEXPOSE 3000"), 0644)
 	assert.NilError(t, err)
 
-	err = ioutil.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM busybox\nEXPOSE 5000"), 0644)
+	err = os.WriteFile(filepath.Join(subDir, "Dockerfile"), []byte("FROM busybox\nEXPOSE 5000"), 0644)
 	assert.NilError(t, err)
 
 	_, err = gitWithinDir(gitDir, "add", "-A")
@@ -249,7 +248,7 @@ func TestCheckoutGit(t *testing.T) {
 	_, err = gitWithinDir(subrepoDir, "config", "user.name", "Docker test")
 	assert.NilError(t, err)
 
-	err = ioutil.WriteFile(filepath.Join(subrepoDir, "subfile"), []byte("subcontents"), 0644)
+	err = os.WriteFile(filepath.Join(subrepoDir, "subfile"), []byte("subcontents"), 0644)
 	assert.NilError(t, err)
 
 	_, err = gitWithinDir(subrepoDir, "add", "-A")
@@ -310,7 +309,7 @@ func TestCheckoutGit(t *testing.T) {
 		assert.NilError(t, err)
 		defer os.RemoveAll(r)
 		if c.submodule {
-			b, err := ioutil.ReadFile(filepath.Join(r, "sub/subfile"))
+			b, err := os.ReadFile(filepath.Join(r, "sub/subfile"))
 			assert.NilError(t, err)
 			assert.Check(t, is.Equal("subcontents", string(b)))
 		} else {
@@ -319,7 +318,7 @@ func TestCheckoutGit(t *testing.T) {
 			assert.Assert(t, os.IsNotExist(err))
 		}
 
-		b, err := ioutil.ReadFile(filepath.Join(r, "Dockerfile"))
+		b, err := os.ReadFile(filepath.Join(r, "Dockerfile"))
 		assert.NilError(t, err)
 		assert.Check(t, is.Equal(c.exp, string(b)))
 	}

builder/remotecontext/remote.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"net/url"
@@ -58,7 +57,7 @@ func GetWithStatusError(address string) (resp *http.Response, err error) {
 		return resp, nil
 	}
 	msg := fmt.Sprintf("failed to GET %s with status %s", address, resp.Status)
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	resp.Body.Close()
 	if err != nil {
 		return nil, errdefs.System(errors.New(msg + ": error reading body"))

builder/remotecontext/remote_test.go

@@ -3,7 +3,6 @@ package remotecontext // import "github.com/docker/docker/builder/remotecontext"
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -52,15 +51,15 @@ func TestSelectAcceptableMIME(t *testing.T) {
 
 func TestInspectEmptyResponse(t *testing.T) {
 	ct := "application/octet-stream"
-	br := ioutil.NopCloser(bytes.NewReader([]byte("")))
+	br := io.NopCloser(bytes.NewReader([]byte("")))
 	contentType, bReader, err := inspectResponse(ct, br, 0)
 	if err == nil {
 		t.Fatal("Should have generated an error for an empty response")
 	}
 	if contentType != "application/octet-stream" {
 		t.Fatalf("Content type should be 'application/octet-stream' but is %q", contentType)
 	}
-	body, err := ioutil.ReadAll(bReader)
+	body, err := io.ReadAll(bReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -71,15 +70,15 @@ func TestInspectEmptyResponse(t *testing.T) {
 
 func TestInspectResponseBinary(t *testing.T) {
 	ct := "application/octet-stream"
-	br := ioutil.NopCloser(bytes.NewReader(binaryContext))
+	br := io.NopCloser(bytes.NewReader(binaryContext))
 	contentType, bReader, err := inspectResponse(ct, br, int64(len(binaryContext)))
 	if err != nil {
 		t.Fatal(err)
 	}
 	if contentType != "application/octet-stream" {
 		t.Fatalf("Content type should be 'application/octet-stream' but is %q", contentType)
 	}
-	body, err := ioutil.ReadAll(bReader)
+	body, err := io.ReadAll(bReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -96,7 +95,7 @@ func TestInspectResponseBinary(t *testing.T) {
 func TestResponseUnsupportedContentType(t *testing.T) {
 	content := []byte(dockerfileContents)
 	ct := "application/json"
-	br := ioutil.NopCloser(bytes.NewReader(content))
+	br := io.NopCloser(bytes.NewReader(content))
 	contentType, bReader, err := inspectResponse(ct, br, int64(len(dockerfileContents)))
 
 	if err == nil {
@@ -105,7 +104,7 @@ func TestResponseUnsupportedContentType(t *testing.T) {
 	if contentType != ct {
 		t.Fatalf("Should not have altered content-type: orig: %s, altered: %s", ct, contentType)
 	}
-	body, err := ioutil.ReadAll(bReader)
+	body, err := io.ReadAll(bReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -117,15 +116,15 @@ func TestResponseUnsupportedContentType(t *testing.T) {
 func TestInspectResponseTextSimple(t *testing.T) {
 	content := []byte(dockerfileContents)
 	ct := "text/plain"
-	br := ioutil.NopCloser(bytes.NewReader(content))
+	br := io.NopCloser(bytes.NewReader(content))
 	contentType, bReader, err := inspectResponse(ct, br, int64(len(content)))
 	if err != nil {
 		t.Fatal(err)
 	}
 	if contentType != "text/plain" {
 		t.Fatalf("Content type should be 'text/plain' but is %q", contentType)
 	}
-	body, err := ioutil.ReadAll(bReader)
+	body, err := io.ReadAll(bReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -136,15 +135,15 @@ func TestInspectResponseTextSimple(t *testing.T) {
 
 func TestInspectResponseEmptyContentType(t *testing.T) {
 	content := []byte(dockerfileContents)
-	br := ioutil.NopCloser(bytes.NewReader(content))
+	br := io.NopCloser(bytes.NewReader(content))
 	contentType, bodyReader, err := inspectResponse("", br, int64(len(content)))
 	if err != nil {
 		t.Fatal(err)
 	}
 	if contentType != "text/plain" {
 		t.Fatalf("Content type should be 'text/plain' but is %q", contentType)
 	}
-	body, err := ioutil.ReadAll(bodyReader)
+	body, err := io.ReadAll(bodyReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -156,15 +155,15 @@ func TestInspectResponseEmptyContentType(t *testing.T) {
 func TestUnknownContentLength(t *testing.T) {
 	content := []byte(dockerfileContents)
 	ct := "text/plain"
-	br := ioutil.NopCloser(bytes.NewReader(content))
+	br := io.NopCloser(bytes.NewReader(content))
 	contentType, bReader, err := inspectResponse(ct, br, -1)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if contentType != "text/plain" {
 		t.Fatalf("Content type should be 'text/plain' but is %q", contentType)
 	}
-	body, err := ioutil.ReadAll(bReader)
+	body, err := io.ReadAll(bReader)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -191,7 +190,7 @@ func TestDownloadRemote(t *testing.T) {
 	assert.NilError(t, err)
 
 	assert.Check(t, is.Equal(mimeTypes.TextPlain, contentType))
-	raw, err := ioutil.ReadAll(content)
+	raw, err := io.ReadAll(content)
 	assert.NilError(t, err)
 	assert.Check(t, is.Equal(dockerfileContents, string(raw)))
 }
@@ -238,5 +237,5 @@ func TestGetWithStatusError(t *testing.T) {
 
 func readBody(b io.ReadCloser) ([]byte, error) {
 	defer b.Close()
-	return ioutil.ReadAll(b)
+	return io.ReadAll(b)
 }

builder/remotecontext/tarsum_test.go

@@ -1,7 +1,6 @@
 package remotecontext // import "github.com/docker/docker/builder/remotecontext"
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -23,7 +22,7 @@ func init() {
 }
 
 func TestCloseRootDirectory(t *testing.T) {
-	contextDir, err := ioutil.TempDir("", "builder-tarsum-test")
+	contextDir, err := os.MkdirTemp("", "builder-tarsum-test")
 	defer os.RemoveAll(contextDir)
 	if err != nil {
 		t.Fatalf("Error with creating temporary directory: %s", err)