github.com/nevins-b/terraform@v0.3.8-0.20170215184714-bbae22007d5a/state/remote/state.go (about)

     1  package remote
     2  
     3  import (
     4  	"bytes"
     5  
     6  	"github.com/hashicorp/terraform/terraform"
     7  )
     8  
     9  // State implements the State interfaces in the state package to handle
    10  // reading and writing the remote state. This State on its own does no
    11  // local caching so every persist will go to the remote storage and local
    12  // writes will go to memory.
    13  type State struct {
    14  	Client Client
    15  
    16  	state, readState *terraform.State
    17  }
    18  
    19  // StateReader impl.
    20  func (s *State) State() *terraform.State {
    21  	return s.state.DeepCopy()
    22  }
    23  
    24  // StateWriter impl.
    25  func (s *State) WriteState(state *terraform.State) error {
    26  	s.state = state
    27  	return nil
    28  }
    29  
    30  // StateRefresher impl.
    31  func (s *State) RefreshState() error {
    32  	payload, err := s.Client.Get()
    33  	if err != nil {
    34  		return err
    35  	}
    36  
    37  	// no remote state is OK
    38  	if payload == nil {
    39  		return nil
    40  	}
    41  
    42  	state, err := terraform.ReadState(bytes.NewReader(payload.Data))
    43  	if err != nil {
    44  		return err
    45  	}
    46  
    47  	s.state = state
    48  	s.readState = state
    49  	return nil
    50  }
    51  
    52  // StatePersister impl.
    53  func (s *State) PersistState() error {
    54  	s.state.IncrementSerialMaybe(s.readState)
    55  
    56  	var buf bytes.Buffer
    57  	if err := terraform.WriteState(s.state, &buf); err != nil {
    58  		return err
    59  	}
    60  
    61  	return s.Client.Put(buf.Bytes())
    62  }
    63  
    64  // Lock calls the Client's Lock method if it's implemented.
    65  func (s *State) Lock(reason string) error {
    66  	if c, ok := s.Client.(stateLocker); ok {
    67  		return c.Lock(reason)
    68  	}
    69  	return nil
    70  }
    71  
    72  // Unlock calls the Client's Unlock method if it's implemented.
    73  func (s *State) Unlock() error {
    74  	if c, ok := s.Client.(stateLocker); ok {
    75  		return c.Unlock()
    76  	}
    77  	return nil
    78  }
    79  
    80  // stateLocker mirrors the state.Locker interface.  This can be implemented by
    81  // Clients to provide methods for locking and unlocking remote state.
    82  type stateLocker interface {
    83  	Lock(reason string) error
    84  	Unlock() error
    85  }