github.com/paultyng/terraform@v0.6.11-0.20180227224804-66ff8f8bed40/command/state_meta.go (about)

     1  package command
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"time"
     7  
     8  	backendlocal "github.com/hashicorp/terraform/backend/local"
     9  	"github.com/hashicorp/terraform/state"
    10  	"github.com/hashicorp/terraform/terraform"
    11  )
    12  
    13  // StateMeta is the meta struct that should be embedded in state subcommands.
    14  type StateMeta struct {
    15  	Meta
    16  }
    17  
    18  // State returns the state for this meta. This gets the appropriate state from
    19  // the backend, but changes the way that backups are done. This configures
    20  // backups to be timestamped rather than just the original state path plus a
    21  // backup path.
    22  func (c *StateMeta) State() (state.State, error) {
    23  	var realState state.State
    24  	backupPath := c.backupPath
    25  	stateOutPath := c.statePath
    26  
    27  	// use the specified state
    28  	if c.statePath != "" {
    29  		realState = &state.LocalState{
    30  			Path: c.statePath,
    31  		}
    32  	} else {
    33  		// Load the backend
    34  		b, err := c.Backend(nil)
    35  		if err != nil {
    36  			return nil, err
    37  		}
    38  
    39  		env := c.Workspace()
    40  		// Get the state
    41  		s, err := b.State(env)
    42  		if err != nil {
    43  			return nil, err
    44  		}
    45  
    46  		// Get a local backend
    47  		localRaw, err := c.Backend(&BackendOpts{ForceLocal: true})
    48  		if err != nil {
    49  			// This should never fail
    50  			panic(err)
    51  		}
    52  		localB := localRaw.(*backendlocal.Local)
    53  		_, stateOutPath, _ = localB.StatePaths(env)
    54  		if err != nil {
    55  			return nil, err
    56  		}
    57  
    58  		realState = s
    59  	}
    60  
    61  	// We always backup state commands, so set the back if none was specified
    62  	// (the default is "-", but some tests bypass the flag parsing).
    63  	if backupPath == "-" || backupPath == "" {
    64  		// Determine the backup path. stateOutPath is set to the resulting
    65  		// file where state is written (cached in the case of remote state)
    66  		backupPath = fmt.Sprintf(
    67  			"%s.%d%s",
    68  			stateOutPath,
    69  			time.Now().UTC().Unix(),
    70  			DefaultBackupExtension)
    71  	}
    72  
    73  	// Wrap it for backups
    74  	realState = &state.BackupState{
    75  		Real: realState,
    76  		Path: backupPath,
    77  	}
    78  
    79  	return realState, nil
    80  }
    81  
    82  // filterInstance filters a single instance out of filter results.
    83  func (c *StateMeta) filterInstance(rs []*terraform.StateFilterResult) (*terraform.StateFilterResult, error) {
    84  	var result *terraform.StateFilterResult
    85  	for _, r := range rs {
    86  		if _, ok := r.Value.(*terraform.InstanceState); !ok {
    87  			continue
    88  		}
    89  
    90  		if result != nil {
    91  			return nil, errors.New(errStateMultiple)
    92  		}
    93  
    94  		result = r
    95  	}
    96  
    97  	return result, nil
    98  }
    99  
   100  const errStateMultiple = `Multiple instances found for the given pattern!
   101  
   102  This command requires that the pattern match exactly one instance
   103  of a resource. To view the matched instances, use "terraform state list".
   104  Please modify the pattern to match only a single instance.`