restic/internal/migrations/upgrade_repo_v2.go
2022-05-09 22:31:30 +02:00

93 lines
2.3 KiB
Go

package migrations
import (
"context"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"github.com/restic/restic/internal/restic"
)
func init() {
register(&UpgradeRepoV2{})
}
type UpgradeRepoV2 struct{}
func (*UpgradeRepoV2) Name() string {
return "upgrade_repo_v2"
}
func (*UpgradeRepoV2) Desc() string {
return "upgrade a repository to version 2"
}
func (*UpgradeRepoV2) Check(ctx context.Context, repo restic.Repository) (bool, error) {
isV1 := repo.Config().Version == 1
return isV1, nil
}
func (*UpgradeRepoV2) upgrade(ctx context.Context, repo restic.Repository) error {
h := restic.Handle{Type: restic.ConfigFile}
// now remove the original file
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 = repo.SaveJSONUnpacked(ctx, restic.ConfigFile, 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 := ioutil.TempDir("", "restic-migrate-upgrade-repo-v2-")
if err != nil {
return fmt.Errorf("create temp dir failed: %w", err)
}
h := restic.Handle{Type: restic.ConfigFile}
// read raw config file and save it to a temp dir, just in case
var rawConfigFile []byte
err = repo.Backend().Load(ctx, h, 0, 0, func(rd io.Reader) (err error) {
rawConfigFile, err = ioutil.ReadAll(rd)
return err
})
if err != nil {
return fmt.Errorf("load config file failed: %w", err)
}
err = ioutil.WriteFile(filepath.Join(tempdir, "config.old"), 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 {
// try contingency methods, reupload the original file
_ = repo.Backend().Remove(ctx, h)
uploadError := repo.Backend().Save(ctx, h, restic.NewByteReader(rawConfigFile, nil))
if uploadError != nil {
return fmt.Errorf("error uploading config (%w), re-uploading old config filed failed as well (%v) but there is a backup in %v", err, uploadError, tempdir)
}
return fmt.Errorf("error uploading config (%w), re-uploadid old config, there is a backup in %v", err, tempdir)
}
_ = os.Remove(backupFileName)
_ = os.Remove(tempdir)
return nil
}