// Apply applies the migration in question.
// This migration merely adds a version file.
func (m Migration) Apply(opts migrate.Options) error {
repolk, err := lock.Lock(opts.Path)
if err != nil {
return err
}
defer repolk.Close()
repo := mfsr.RepoPath(opts.Path)
// first, check if there is a version file.
// if there is, bail out.
if v, err := repo.Version(); err == nil {
return fmt.Errorf("repo at %s is version %s (not 0)", opts.Path, v)
} else if !strings.Contains(err.Error(), "no version file in repo") {
return err
}
// add the version file
if err := repo.WriteVersion("1"); err != nil {
return err
}
if opts.Verbose {
fmt.Println("wrote version file")
}
return nil
}
// Revert un-applies the migration in question. This should be best-effort.
// Some migrations are definitively one-way. If so, return an error.
func (m Migration) Revert(opts migrate.Options) error {
repo := mfsr.RepoPath(opts.Path)
repolk, err := lock.Lock(opts.Path)
if err != nil {
return err
}
defer repolk.Close()
if err := repo.CheckVersion("1"); err != nil {
return err
}
// remove the version file
if err := os.Remove(repo.VersionFile()); err != nil {
return err
}
if opts.Verbose {
fmt.Println("deleted version file")
}
return nil
}