feat(wrtag): chmod files with respect to umask

closes #204

Author: sentriz

cmd/internal/wrtagflag/wrtagflag.go

@@ -116,19 +116,6 @@ func ResearchLinks() *researchlink.Builder {
 	return &r
 }
 
-func OperationByName(name string, dryRun bool) (wrtag.FileSystemOperation, error) {
-	switch name {
-	case "copy":
-		return wrtag.NewCopy(dryRun), nil
-	case "move":
-		return wrtag.NewMove(dryRun), nil
-	case "reflink":
-		return wrtag.NewReflink(dryRun), nil
-	default:
-		return nil, errors.New("unknown operation")
-	}
-}
-
 var _ flag.Value = (*pathFormatParser)(nil)
 var _ flag.Value = (*researchLinkParser)(nil)
 var _ flag.Value = (*notificationsParser)(nil)
@@ -345,3 +332,19 @@ func (rl *rateLimitParser) String() string {
 	}
 	return dur.String()
 }
+
+// DefaultFileMode will be overridden in _unix.go to respect umask.
+var DefaultFileMode os.FileMode = 0666
+
+func OperationByName(name string, dryRun bool) (wrtag.FileSystemOperation, error) {
+	switch name {
+	case "copy":
+		return wrtag.NewCopy(dryRun, DefaultFileMode), nil
+	case "move":
+		return wrtag.NewMove(dryRun, DefaultFileMode), nil
+	case "reflink":
+		return wrtag.NewReflink(dryRun, DefaultFileMode), nil
+	default:
+		return nil, errors.New("unknown operation")
+	}
+}

cmd/internal/wrtagflag/wrtagflag_unix.go

@@ -0,0 +1,14 @@
+//go:build unix
+
+package wrtagflag
+
+import (
+	"io/fs"
+	"syscall"
+)
+
+func init() {
+	umask := syscall.Umask(0)
+	syscall.Umask(umask)
+	DefaultFileMode = fs.FileMode(0o666 &^ umask) //nolint:gosec
+}

cmd/wrtag/main.go

@@ -236,7 +236,7 @@ func runSync(ctx context.Context, cfg *wrtag.Config, stats *syncStats, dirs []st
 		wg.Go(func() {
 			ctxConsume(ctx, leaves, func(dir string) {
 				stats.saw.Add(1)
-				r, err := syncDir(ctx, cfg, ageYounger, ageOlder, wrtag.NewMove(dryRun), dir)
+				r, err := syncDir(ctx, cfg, ageYounger, ageOlder, wrtag.NewMove(dryRun, wrtagflag.DefaultFileMode), dir)
 				if err != nil && !errors.Is(err, context.Canceled) {
 					stats.errors.Add(1)
 					slog.ErrorContext(ctx, "processing dir", "dir", dir, "err", err)

cmd/wrtag/main_test.go

@@ -18,6 +18,7 @@ import (
 	"testing"
 
 	"github.com/rogpeppe/go-internal/testscript"
+	"go.senan.xyz/wrtag/cmd/internal/wrtagflag"
 	"go.senan.xyz/wrtag/fileutil"
 	"go.senan.xyz/wrtag/tags"
 	"go.senan.xyz/wrtag/tags/normtag"
@@ -38,13 +39,15 @@ func TestMain(m *testing.M) {
 	os.Setenv("WRTAG_CAA_RATE_LIMIT", "0")
 
 	testscript.Main(m, map[string]func(){
-		"wrtag":    main,
-		"tag":      mainTag,
-		"find":     mainFind,
-		"touch":    mainTouch,
-		"mime":     mainMIME,
-		"mod-time": mainModTime,
-		"rand":     mainRand,
+		"wrtag":     main,
+		"tag":       mainTag,
+		"find":      mainFind,
+		"touch":     mainTouch,
+		"mime":      mainMIME,
+		"chmod":     mainChmod,
+		"file-mode": mainFileMode,
+		"mod-time":  mainModTime,
+		"rand":      mainRand,
 	})
 }
 
@@ -54,6 +57,13 @@ func TestScripts(t *testing.T) {
 	testscript.Run(t, testscript.Params{
 		Dir:                 "testdata/scripts",
 		RequireExplicitExec: true,
+		Condition: func(cond string) (bool, error) {
+			if mask, ok := strings.CutPrefix(cond, "defaultfilemode:"); ok {
+				want, _ := strconv.ParseInt(mask, 8, 32)
+				return wrtagflag.DefaultFileMode == os.FileMode(want), nil
+			}
+			return false, fmt.Errorf("unknown condition %q", cond)
+		},
 	})
 }
 
@@ -156,6 +166,45 @@ func mainMIME() {
 	fmt.Println(mime)
 }
 
+func mainChmod() {
+	flag.Parse()
+
+	mode, err := strconv.ParseInt(flag.Arg(0), 8, 32)
+	if err != nil {
+		log.Fatalf("parse mode: %v", err)
+	}
+
+	pat := flag.Arg(1)
+	paths := parsePattern(pat)
+	if len(paths) == 0 {
+		log.Fatalf("no paths to match pattern")
+	}
+
+	for _, p := range paths {
+		if err := os.Chmod(p, os.FileMode(mode)); err != nil {
+			log.Fatalf("chmod %s: %v", p, err)
+		}
+	}
+}
+
+func mainFileMode() {
+	flag.Parse()
+
+	pat := flag.Arg(0)
+	paths := parsePattern(pat)
+	if len(paths) == 0 {
+		log.Fatalf("no paths to match pattern")
+	}
+
+	for _, p := range paths {
+		info, err := os.Stat(p)
+		if err != nil {
+			log.Fatalf("error stating: %v", err)
+		}
+		fmt.Printf("%04o\n", info.Mode().Perm())
+	}
+}
+
 func mainModTime() {
 	flag.Parse()
 

cmd/wrtag/testdata/scripts/copy-preserves-perms.txtar

@@ -0,0 +1,32 @@
+[!defaultfilemode:644] skip 'assumes default permission mode 0644'
+
+exec tag write kat_moda/01.flac
+exec tag write kat_moda/02.flac
+exec tag write kat_moda/03.flac
+exec touch kat_moda/keep-me
+exec touch kat_moda/cover.png
+
+exec chmod 0612 kat_moda/*.flac
+exec chmod 0612 kat_moda/cover.png
+exec chmod 0612 kat_moda/keep-me
+
+exec file-mode kat_moda/*.flac
+stdout -count=3 0612
+exec file-mode kat_moda/cover.png
+stdout 0612
+exec file-mode kat_moda/keep-me
+stdout 0612
+
+env WRTAG_PATH_FORMAT='albums/{{ .Release.Title }}/{{ .Track.Position }}{{ .Ext }}'
+env WRTAG_KEEP_FILE=keep-me
+
+# copy
+exec wrtag copy -yes -mbid e47d04a4-7460-427d-a731-cc82386d85f1 kat_moda/
+
+# expect all respect umask
+exec file-mode 'albums/Kat Moda/*.flac'
+stdout -count=3 0644
+exec file-mode 'albums/Kat Moda/cover.png'
+stdout 0644
+exec file-mode 'albums/Kat Moda/keep-me'
+stdout 0644

wrtag.go

@@ -770,12 +770,13 @@ func NewDirContext() DirContext {
 
 // Move implements FileSystemOperation to move files from source to destination.
 type Move struct {
-	dryRun bool
+	dryRun   bool
+	destMode os.FileMode
 }
 
 // NewMove creates a new Move operation with the specified dry-run mode.
 // If dryRun is true, no files will actually be moved.
-func NewMove(dryRun bool) Move { return Move{dryRun: dryRun} }
+func NewMove(dryRun bool, destMode os.FileMode) Move { return Move{dryRun: dryRun, destMode: destMode} }
 
 // CanModifyDest returns whether this operation can modify destination files.
 // For Move operations, this is determined by the dryRun setting.
@@ -811,10 +812,14 @@ func (m Move) ProcessPath(ctx context.Context, dc DirContext, src, dest string)
 			if err := os.Remove(src); err != nil {
 				return fmt.Errorf("remove from move: %w", err)
 			}
+			if err := os.Chmod(dest, m.destMode); err != nil {
+				return fmt.Errorf("chmod dest: %w", err)
+			}
 
 			slog.DebugContext(ctx, "moved path", "from", src, "to", dest)
 			return nil
 		}
+
 		return fmt.Errorf("rename: %w", err)
 	}
 
@@ -853,12 +858,13 @@ func (m Move) PostSource(ctx context.Context, dc DirContext, limit string, src s
 
 // Copy implements FileSystemOperation to copy files from source to destination.
 type Copy struct {
-	dryRun bool
+	dryRun   bool
+	destMode os.FileMode
 }
 
 // NewCopy creates a new Copy operation with the specified dry-run mode.
 // If dryRun is true, no files will actually be copied.
-func NewCopy(dryRun bool) Copy { return Copy{dryRun: dryRun} }
+func NewCopy(dryRun bool, destMode os.FileMode) Copy { return Copy{dryRun: dryRun, destMode: destMode} }
 
 // CanModifyDest returns whether this operation can modify destination files.
 // For Copy operations, this is determined by the dryRun setting.
@@ -889,6 +895,10 @@ func (c Copy) ProcessPath(ctx context.Context, dc DirContext, src, dest string)
 		return err
 	}
 
+	if err := os.Chmod(dest, c.destMode); err != nil {
+		return fmt.Errorf("chmod dest: %w", err)
+	}
+
 	slog.DebugContext(ctx, "copied path", "from", src, "to", dest)
 	return nil
 }
@@ -901,12 +911,15 @@ func (Copy) PostSource(ctx context.Context, dc DirContext, limit string, src str
 
 // Reflink implements FileSystemOperation to copy files using reflink (copy-on-write) when supported.
 type Reflink struct {
-	dryRun bool
+	dryRun   bool
+	destMode os.FileMode
 }
 
 // NewReflink creates a new Reflink operation with the specified dry-run mode.
 // If dryRun is true, no files will actually be reflinked.
-func NewReflink(dryRun bool) Reflink { return Reflink{dryRun: dryRun} }
+func NewReflink(dryRun bool, destMode os.FileMode) Reflink {
+	return Reflink{dryRun: dryRun, destMode: destMode}
+}
 
 // CanModifyDest returns whether this operation can modify destination files.
 // For Reflink operations, this is determined by the dryRun setting.
@@ -937,6 +950,10 @@ func (c Reflink) ProcessPath(ctx context.Context, dc DirContext, src, dest strin
 		return fmt.Errorf("reflink file: %w", err)
 	}
 
+	if err := os.Chmod(dest, c.destMode); err != nil {
+		return fmt.Errorf("chmod dest: %w", err)
+	}
+
 	slog.DebugContext(ctx, "reflinked path", "from", src, "to", dest)
 	return nil
 }

wrtag_test.go

@@ -145,29 +145,29 @@ func TestNewDirContext(t *testing.T) {
 func TestMoveCanModifyDest(t *testing.T) {
 	t.Parallel()
 
-	move := NewMove(false)
+	move := NewMove(false, 0600)
 	assert.True(t, move.CanModifyDest())
 
-	dryRunMove := NewMove(true)
+	dryRunMove := NewMove(true, 0600)
 	assert.False(t, dryRunMove.CanModifyDest())
 }
 
 func TestCopyCanModifyDest(t *testing.T) {
 	t.Parallel()
 
-	cpy := NewCopy(false)
+	cpy := NewCopy(false, 0600)
 	assert.True(t, cpy.CanModifyDest())
 
-	dryRunCopy := NewCopy(true)
+	dryRunCopy := NewCopy(true, 0600)
 	assert.False(t, dryRunCopy.CanModifyDest())
 }
 
 func TestReflinkCanModifyDest(t *testing.T) {
 	t.Parallel()
 
-	reflink := NewReflink(false)
+	reflink := NewReflink(false, 0600)
 	assert.True(t, reflink.CanModifyDest())
 
-	dryRunReflink := NewReflink(true)
+	dryRunReflink := NewReflink(true, 0600)
 	assert.False(t, dryRunReflink.CanModifyDest())
 }