migrations: move logic of upgrade_repo_v2 to repository package

The migration modifies repository internals and thus should live within
the repository package.

internal/migrations/upgrade_repo_v2.go

@@ -3,10 +3,8 @@ package migrations
 import (
 	"context"
 	"fmt"
-	"os"
-	"path/filepath"
 
-	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/repository"
 	"github.com/restic/restic/internal/restic"
 )
 
@@ -14,26 +12,6 @@ func init() {
 	register(&UpgradeRepoV2{})
 }
 
-type UpgradeRepoV2Error struct {
-	UploadNewConfigError   error
-	ReuploadOldConfigError error
-
-	BackupFilePath string
-}
-
-func (err *UpgradeRepoV2Error) Error() string {
-	if err.ReuploadOldConfigError != nil {
-		return fmt.Sprintf("error uploading config (%v), re-uploading old config filed failed as well (%v), but there is a backup of the config file in %v", err.UploadNewConfigError, err.ReuploadOldConfigError, err.BackupFilePath)
-	}
-
-	return fmt.Sprintf("error uploading config (%v), re-uploaded old config was successful, there is a backup of the config file in %v", err.UploadNewConfigError, err.BackupFilePath)
-}
-
-func (err *UpgradeRepoV2Error) Unwrap() error {
-	// consider the original upload error as the primary cause
-	return err.UploadNewConfigError
-}
-
 type UpgradeRepoV2 struct{}
 
 func (*UpgradeRepoV2) Name() string {
@@ -56,70 +34,7 @@ func (*UpgradeRepoV2) Check(_ context.Context, repo restic.Repository) (bool, st
 func (*UpgradeRepoV2) RepoCheck() bool {
 	return true
 }
-func (*UpgradeRepoV2) upgrade(ctx context.Context, repo restic.Repository) error {
-	h := backend.Handle{Type: backend.ConfigFile}
-
-	if !repo.Backend().HasAtomicReplace() {
-		// remove the original file for backends which do not support atomic overwriting
-		err := repo.Backend().Remove(ctx, h)
-		if err != nil {
-			return fmt.Errorf("remove config failed: %w", err)
-		}
-	}
-
-	// upgrade config
-	cfg := repo.Config()
-	cfg.Version = 2
-
-	err := restic.SaveConfig(ctx, repo, cfg)
-	if err != nil {
-		return fmt.Errorf("save new config file failed: %w", err)
-	}
-
-	return nil
-}
 
 func (m *UpgradeRepoV2) Apply(ctx context.Context, repo restic.Repository) error {
-	tempdir, err := os.MkdirTemp("", "restic-migrate-upgrade-repo-v2-")
+	return repository.UpgradeRepo(ctx, repo.(*repository.Repository))
-	if err != nil {
-		return fmt.Errorf("create temp dir failed: %w", err)
-	}
-
-	h := backend.Handle{Type: restic.ConfigFile}
-
-	// read raw config file and save it to a temp dir, just in case
-	rawConfigFile, err := repo.LoadRaw(ctx, restic.ConfigFile, restic.ID{})
-	if err != nil {
-		return fmt.Errorf("load config file failed: %w", err)
-	}
-
-	backupFileName := filepath.Join(tempdir, "config")
-	err = os.WriteFile(backupFileName, rawConfigFile, 0600)
-	if err != nil {
-		return fmt.Errorf("write config file backup to %v failed: %w", tempdir, err)
-	}
-
-	// run the upgrade
-	err = m.upgrade(ctx, repo)
-	if err != nil {
-
-		// build an error we can return to the caller
-		repoError := &UpgradeRepoV2Error{
-			UploadNewConfigError: err,
-			BackupFilePath:       backupFileName,
-		}
-
-		// try contingency methods, reupload the original file
-		_ = repo.Backend().Remove(ctx, h)
-		err = repo.Backend().Save(ctx, h, backend.NewByteReader(rawConfigFile, nil))
-		if err != nil {
-			repoError.ReuploadOldConfigError = err
-		}
-
-		return repoError
-	}
-
-	_ = os.Remove(backupFileName)
-	_ = os.Remove(tempdir)
-	return nil
 }

internal/migrations/upgrade_repo_v2_test.go

@@ -2,15 +2,9 @@ package migrations
 
 import (
 	"context"
-	"os"
-	"path/filepath"
-	"sync"
 	"testing"
 
-	"github.com/restic/restic/internal/backend"
-	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/repository"
-	"github.com/restic/restic/internal/test"
 )
 
 func TestUpgradeRepoV2(t *testing.T) {
@@ -35,73 +29,3 @@ func TestUpgradeRepoV2(t *testing.T) {
 		t.Fatal(err)
 	}
 }
-
-type failBackend struct {
-	backend.Backend
-
-	mu                        sync.Mutex
-	ConfigFileSavesUntilError uint
-}
-
-func (be *failBackend) Save(ctx context.Context, h backend.Handle, rd backend.RewindReader) error {
-	if h.Type != backend.ConfigFile {
-		return be.Backend.Save(ctx, h, rd)
-	}
-
-	be.mu.Lock()
-	if be.ConfigFileSavesUntilError == 0 {
-		be.mu.Unlock()
-		return errors.New("failure induced for testing")
-	}
-
-	be.ConfigFileSavesUntilError--
-	be.mu.Unlock()
-
-	return be.Backend.Save(ctx, h, rd)
-}
-
-func TestUpgradeRepoV2Failure(t *testing.T) {
-	be := repository.TestBackend(t)
-
-	// wrap backend so that it fails upgrading the config after the initial write
-	be = &failBackend{
-		ConfigFileSavesUntilError: 1,
-		Backend:                   be,
-	}
-
-	repo := repository.TestRepositoryWithBackend(t, be, 1, repository.Options{})
-	if repo.Config().Version != 1 {
-		t.Fatal("test repo has wrong version")
-	}
-
-	m := &UpgradeRepoV2{}
-
-	ok, _, err := m.Check(context.Background(), repo)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !ok {
-		t.Fatal("migration check returned false")
-	}
-
-	err = m.Apply(context.Background(), repo)
-	if err == nil {
-		t.Fatal("expected error returned from Apply(), got nil")
-	}
-
-	upgradeErr := err.(*UpgradeRepoV2Error)
-	if upgradeErr.UploadNewConfigError == nil {
-		t.Fatal("expected upload error, got nil")
-	}
-
-	if upgradeErr.ReuploadOldConfigError == nil {
-		t.Fatal("expected reupload error, got nil")
-	}
-
-	if upgradeErr.BackupFilePath == "" {
-		t.Fatal("no backup file path found")
-	}
-	test.OK(t, os.Remove(upgradeErr.BackupFilePath))
-	test.OK(t, os.Remove(filepath.Dir(upgradeErr.BackupFilePath)))
-}

internal/repository/upgrade_repo.go

@@ -0,0 +1,103 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/restic"
+)
+
+type upgradeRepoV2Error struct {
+	UploadNewConfigError   error
+	ReuploadOldConfigError error
+
+	BackupFilePath string
+}
+
+func (err *upgradeRepoV2Error) Error() string {
+	if err.ReuploadOldConfigError != nil {
+		return fmt.Sprintf("error uploading config (%v), re-uploading old config filed failed as well (%v), but there is a backup of the config file in %v", err.UploadNewConfigError, err.ReuploadOldConfigError, err.BackupFilePath)
+	}
+
+	return fmt.Sprintf("error uploading config (%v), re-uploaded old config was successful, there is a backup of the config file in %v", err.UploadNewConfigError, err.BackupFilePath)
+}
+
+func (err *upgradeRepoV2Error) Unwrap() error {
+	// consider the original upload error as the primary cause
+	return err.UploadNewConfigError
+}
+
+func upgradeRepository(ctx context.Context, repo *Repository) error {
+	h := backend.Handle{Type: backend.ConfigFile}
+
+	if !repo.be.HasAtomicReplace() {
+		// remove the original file for backends which do not support atomic overwriting
+		err := repo.be.Remove(ctx, h)
+		if err != nil {
+			return fmt.Errorf("remove config failed: %w", err)
+		}
+	}
+
+	// upgrade config
+	cfg := repo.Config()
+	cfg.Version = 2
+
+	err := restic.SaveConfig(ctx, repo, cfg)
+	if err != nil {
+		return fmt.Errorf("save new config file failed: %w", err)
+	}
+
+	return nil
+}
+
+func UpgradeRepo(ctx context.Context, repo *Repository) error {
+	if repo.Config().Version != 1 {
+		return fmt.Errorf("repository has version %v, only upgrades from version 1 are supported", repo.Config().Version)
+	}
+
+	tempdir, err := os.MkdirTemp("", "restic-migrate-upgrade-repo-v2-")
+	if err != nil {
+		return fmt.Errorf("create temp dir failed: %w", err)
+	}
+
+	h := backend.Handle{Type: restic.ConfigFile}
+
+	// read raw config file and save it to a temp dir, just in case
+	rawConfigFile, err := repo.LoadRaw(ctx, restic.ConfigFile, restic.ID{})
+	if err != nil {
+		return fmt.Errorf("load config file failed: %w", err)
+	}
+
+	backupFileName := filepath.Join(tempdir, "config")
+	err = os.WriteFile(backupFileName, rawConfigFile, 0600)
+	if err != nil {
+		return fmt.Errorf("write config file backup to %v failed: %w", tempdir, err)
+	}
+
+	// run the upgrade
+	err = upgradeRepository(ctx, repo)
+	if err != nil {
+
+		// build an error we can return to the caller
+		repoError := &upgradeRepoV2Error{
+			UploadNewConfigError: err,
+			BackupFilePath:       backupFileName,
+		}
+
+		// try contingency methods, reupload the original file
+		_ = repo.Backend().Remove(ctx, h)
+		err = repo.Backend().Save(ctx, h, backend.NewByteReader(rawConfigFile, nil))
+		if err != nil {
+			repoError.ReuploadOldConfigError = err
+		}
+
+		return repoError
+	}
+
+	_ = os.Remove(backupFileName)
+	_ = os.Remove(tempdir)
+	return nil
+}

internal/repository/upgrade_repo_test.go

@@ -0,0 +1,82 @@
+package repository
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+
+	"github.com/restic/restic/internal/backend"
+	"github.com/restic/restic/internal/errors"
+	rtest "github.com/restic/restic/internal/test"
+)
+
+func TestUpgradeRepoV2(t *testing.T) {
+	repo := TestRepositoryWithVersion(t, 1)
+	if repo.Config().Version != 1 {
+		t.Fatal("test repo has wrong version")
+	}
+
+	err := UpgradeRepo(context.Background(), repo.(*Repository))
+	rtest.OK(t, err)
+}
+
+type failBackend struct {
+	backend.Backend
+
+	mu                        sync.Mutex
+	ConfigFileSavesUntilError uint
+}
+
+func (be *failBackend) Save(ctx context.Context, h backend.Handle, rd backend.RewindReader) error {
+	if h.Type != backend.ConfigFile {
+		return be.Backend.Save(ctx, h, rd)
+	}
+
+	be.mu.Lock()
+	if be.ConfigFileSavesUntilError == 0 {
+		be.mu.Unlock()
+		return errors.New("failure induced for testing")
+	}
+
+	be.ConfigFileSavesUntilError--
+	be.mu.Unlock()
+
+	return be.Backend.Save(ctx, h, rd)
+}
+
+func TestUpgradeRepoV2Failure(t *testing.T) {
+	be := TestBackend(t)
+
+	// wrap backend so that it fails upgrading the config after the initial write
+	be = &failBackend{
+		ConfigFileSavesUntilError: 1,
+		Backend:                   be,
+	}
+
+	repo := TestRepositoryWithBackend(t, be, 1, Options{})
+	if repo.Config().Version != 1 {
+		t.Fatal("test repo has wrong version")
+	}
+
+	err := UpgradeRepo(context.Background(), repo.(*Repository))
+	if err == nil {
+		t.Fatal("expected error returned from Apply(), got nil")
+	}
+
+	upgradeErr := err.(*upgradeRepoV2Error)
+	if upgradeErr.UploadNewConfigError == nil {
+		t.Fatal("expected upload error, got nil")
+	}
+
+	if upgradeErr.ReuploadOldConfigError == nil {
+		t.Fatal("expected reupload error, got nil")
+	}
+
+	if upgradeErr.BackupFilePath == "" {
+		t.Fatal("no backup file path found")
+	}
+	rtest.OK(t, os.Remove(upgradeErr.BackupFilePath))
+	rtest.OK(t, os.Remove(filepath.Dir(upgradeErr.BackupFilePath)))
+}