Deprecate s3legacy layout

changelog/unreleased/issue-4602

@@ -1,7 +1,7 @@
-Change: Deprecate legacy index format
+Change: Deprecate legacy index format and s3legacy layout
 
 Support for the legacy index format used by restic before version 0.2.0 has
-been depreacted and will be removed in the next minor restic version. You can
+been deprecated and will be removed in the next minor restic version. You can
 use `restic repair index` to update the index to the current format.
 
 It is possible to temporarily reenable support for the legacy index format by
@@ -9,5 +9,15 @@ setting the environment variable
 `RESTIC_FEATURES=deprecate-legacy-index=false`. Note that this feature flag
 will be removed in the next minor restic version.
 
+Support for the s3legacy layout used for the S3 backend before restic 0.7.0
+has been deprecated and will be removed in the next minor restic version. You
+can migrate your S3 repository using `RESTIC_FEATURES=deprecate-s3-legacy-layout=false restic migrate s3_layout`.
+
+It is possible to temporarily reenable support for the legacy s3layout by
+setting the environment variable
+`RESTIC_FEATURES=deprecate-s3-legacy-layout=false`. Note that this feature flag
+will be removed in the next minor restic version.
+
 https://github.com/restic/restic/issues/4602
 https://github.com/restic/restic/pull/4724
+https://github.com/restic/restic/pull/4743

cmd/restic/cmd_restore_integration_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/restic/restic/internal/feature"
 	"github.com/restic/restic/internal/filter"
 	"github.com/restic/restic/internal/restic"
 	rtest "github.com/restic/restic/internal/test"
@@ -274,6 +275,7 @@ func TestRestoreNoMetadataOnIgnoredIntermediateDirs(t *testing.T) {
 }
 
 func TestRestoreLocalLayout(t *testing.T) {
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeprecateS3LegacyLayout, false)()
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 

internal/backend/layout/layout.go

@@ -10,6 +10,7 @@ import (
 	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
+	"github.com/restic/restic/internal/feature"
 	"github.com/restic/restic/internal/fs"
 	"github.com/restic/restic/internal/restic"
 )
@@ -93,6 +94,8 @@ func hasBackendFile(ctx context.Context, fs Filesystem, dir string) (bool, error
 // cannot be detected automatically.
 var ErrLayoutDetectionFailed = errors.New("auto-detecting the filesystem layout failed")
 
+var ErrLegacyLayoutFound = errors.New("detected legacy S3 layout. Use `RESTIC_FEATURES=deprecate-s3-legacy-layout=false restic migrate s3_layout` to migrate your repository")
+
 // DetectLayout tries to find out which layout is used in a local (or sftp)
 // filesystem at the given path. If repo is nil, an instance of LocalFilesystem
 // is used.
@@ -123,6 +126,10 @@ func DetectLayout(ctx context.Context, repo Filesystem, dir string) (Layout, err
 	}
 
 	if foundKeyFile && !foundKeysFile {
+		if feature.Flag.Enabled(feature.DeprecateS3LegacyLayout) {
+			return nil, ErrLegacyLayoutFound
+		}
+
 		debug.Log("found s3 layout at %v", dir)
 		return &S3LegacyLayout{
 			Path: dir,
@@ -145,6 +152,10 @@ func ParseLayout(ctx context.Context, repo Filesystem, layout, defaultLayout, pa
 			Join: repo.Join,
 		}
 	case "s3legacy":
+		if feature.Flag.Enabled(feature.DeprecateS3LegacyLayout) {
+			return nil, ErrLegacyLayoutFound
+		}
+
 		l = &S3LegacyLayout{
 			Path: path,
 			Join: repo.Join,

internal/backend/layout/layout_test.go

@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/feature"
 	rtest "github.com/restic/restic/internal/test"
 )
 
@@ -352,6 +353,7 @@ func TestS3LegacyLayout(t *testing.T) {
 }
 
 func TestDetectLayout(t *testing.T) {
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeprecateS3LegacyLayout, false)()
 	path := rtest.TempDir(t)
 
 	var tests = []struct {
@@ -389,6 +391,7 @@ func TestDetectLayout(t *testing.T) {
 }
 
 func TestParseLayout(t *testing.T) {
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeprecateS3LegacyLayout, false)()
 	path := rtest.TempDir(t)
 
 	var tests = []struct {

internal/backend/local/config.go

@@ -10,7 +10,7 @@ import (
 // Config holds all information needed to open a local repository.
 type Config struct {
 	Path   string
-	Layout string `option:"layout" help:"use this backend directory layout (default: auto-detect)"`
+	Layout string `option:"layout" help:"use this backend directory layout (default: auto-detect) (deprecated)"`
 
 	Connections uint `option:"connections" help:"set a limit for the number of concurrent operations (default: 2)"`
 }

internal/backend/local/layout_test.go

@@ -6,10 +6,12 @@ import (
 	"testing"
 
 	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/feature"
 	rtest "github.com/restic/restic/internal/test"
 )
 
 func TestLayout(t *testing.T) {
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeprecateS3LegacyLayout, false)()
 	path := rtest.TempDir(t)
 
 	var tests = []struct {

internal/backend/s3/config.go

@@ -20,7 +20,7 @@ type Config struct {
 	Secret       options.SecretString
 	Bucket       string
 	Prefix       string
-	Layout       string `option:"layout" help:"use this backend layout (default: auto-detect)"`
+	Layout       string `option:"layout" help:"use this backend layout (default: auto-detect) (deprecated)"`
 	StorageClass string `option:"storage-class" help:"set S3 storage class (STANDARD, STANDARD_IA, ONEZONE_IA, INTELLIGENT_TIERING or REDUCED_REDUNDANCY)"`
 
 	Connections   uint   `option:"connections" help:"set a limit for the number of concurrent connections (default: 5)"`

internal/backend/sftp/config.go

@@ -13,7 +13,7 @@ import (
 type Config struct {
 	User, Host, Port, Path string
 
-	Layout  string `option:"layout"  help:"use this backend directory layout (default: auto-detect)"`
+	Layout  string `option:"layout"  help:"use this backend directory layout (default: auto-detect) (deprecated)"`
 	Command string `option:"command" help:"specify command to create sftp connection"`
 	Args    string `option:"args"    help:"specify arguments for ssh"`
 

internal/backend/sftp/layout_test.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/backend/sftp"
+	"github.com/restic/restic/internal/feature"
 	rtest "github.com/restic/restic/internal/test"
 )
 
@@ -16,6 +17,7 @@ func TestLayout(t *testing.T) {
 		t.Skip("sftp server binary not available")
 	}
 
+	defer feature.TestSetFlag(t, feature.Flag, feature.DeprecateS3LegacyLayout, false)()
 	path := rtest.TempDir(t)
 
 	var tests = []struct {

internal/feature/registry.go

@@ -6,12 +6,14 @@ var Flag = New()
 // flag names are written in kebab-case
 const (
 	DeprecateLegacyIndex    FlagName = "deprecate-legacy-index"
+	DeprecateS3LegacyLayout FlagName = "deprecate-s3-legacy-layout"
 	DeviceIDForHardlinks    FlagName = "device-id-for-hardlinks"
 )
 
 func init() {
 	Flag.SetFlags(map[FlagName]FlagDesc{
 		DeprecateLegacyIndex:    {Type: Beta, Description: "disable support for index format used by restic 0.1.0. Use `restic repair index` to update the index if necessary."},
+		DeprecateS3LegacyLayout: {Type: Beta, Description: "disable support for S3 legacy layout used up to restic 0.7.0. Use `RESTIC_FEATURES=deprecate-s3-legacy-layout=false restic migrate s3_layout` to migrate your S3 repository if necessary."},
 		DeviceIDForHardlinks:    {Type: Alpha, Description: "store deviceID only for hardlinks to reduce metadata changes for example when using btrfs subvolumes. Will be removed in a future restic version after repository format 3 is available"},
 	})
 }