github.com/adrian-bl/terraform@v0.7.0-rc2.0.20160705220747-de0a34fc3517/state/backup.go (about)

     1  package state
     2  
     3  import (
     4  	"github.com/hashicorp/terraform/terraform"
     5  )
     6  
     7  // BackupState wraps a State that backs up the state on the first time that
     8  // a WriteState or PersistState is called.
     9  //
    10  // If Path exists, it will be overwritten.
    11  type BackupState struct {
    12  	Real State
    13  	Path string
    14  
    15  	done bool
    16  }
    17  
    18  func (s *BackupState) State() *terraform.State {
    19  	return s.Real.State()
    20  }
    21  
    22  func (s *BackupState) RefreshState() error {
    23  	return s.Real.RefreshState()
    24  }
    25  
    26  func (s *BackupState) WriteState(state *terraform.State) error {
    27  	if !s.done {
    28  		if err := s.backup(); err != nil {
    29  			return err
    30  		}
    31  	}
    32  
    33  	return s.Real.WriteState(state)
    34  }
    35  
    36  func (s *BackupState) PersistState() error {
    37  	if !s.done {
    38  		if err := s.backup(); err != nil {
    39  			return err
    40  		}
    41  	}
    42  
    43  	return s.Real.PersistState()
    44  }
    45  
    46  func (s *BackupState) backup() error {
    47  	state := s.Real.State()
    48  	if state == nil {
    49  		if err := s.Real.RefreshState(); err != nil {
    50  			return err
    51  		}
    52  
    53  		state = s.Real.State()
    54  	}
    55  
    56  	ls := &LocalState{Path: s.Path}
    57  	if err := ls.WriteState(state); err != nil {
    58  		return err
    59  	}
    60  
    61  	s.done = true
    62  	return nil
    63  }