command: use new state lock/unlock helpers for better UX

command/meta_backend.go

@@ -16,6 +16,7 @@ import (
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/hcl"
 	"github.com/hashicorp/terraform/backend"
+	clistate "github.com/hashicorp/terraform/command/state"
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
@@ -531,11 +532,12 @@ func (m *Meta) backendFromPlan(opts *BackendOpts) (backend.Backend, error) {
 		return nil, fmt.Errorf("Error reading state: %s", err)
 	}
 
-	unlock, err := lockState(realMgr, "backend from plan")
+	// Lock the state if we can
+	err = clistate.Lock(realMgr, "backend from plan", m.Ui, m.Colorize())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Error locking state: %s", err)
 	}
-	defer unlock()
+	defer clistate.Unlock(realMgr, m.Ui, m.Colorize())
 
 	if err := realMgr.RefreshState(); err != nil {
 		return nil, fmt.Errorf("Error reading state: %s", err)
@@ -983,11 +985,12 @@ func (m *Meta) backend_C_r_s(
 		}
 	}
 
-	unlock, err := lockState(sMgr, "backend_C_r_s")
+	// Lock the state if we can
+	err = clistate.Lock(sMgr, "backend from config", m.Ui, m.Colorize())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Error locking state: %s", err)
 	}
-	defer unlock()
+	defer clistate.Unlock(sMgr, m.Ui, m.Colorize())
 
 	// Store the metadata in our saved state location
 	s := sMgr.State()
@@ -1087,11 +1090,12 @@ func (m *Meta) backend_C_r_S_changed(
 		}
 	}
 
-	unlock, err := lockState(sMgr, "backend_C_r_S_changed")
+	// Lock the state if we can
+	err = clistate.Lock(sMgr, "backend from config", m.Ui, m.Colorize())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Error locking state: %s", err)
 	}
-	defer unlock()
+	defer clistate.Unlock(sMgr, m.Ui, m.Colorize())
 
 	// Update the backend state
 	s = sMgr.State()
@@ -1244,11 +1248,12 @@ func (m *Meta) backend_C_R_S_unchanged(
 		}
 	}
 
-	unlock, err := lockState(sMgr, "backend_C_R_S_unchanged")
+	// Lock the state if we can
+	err = clistate.Lock(sMgr, "backend from config", m.Ui, m.Colorize())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("Error locking state: %s", err)
 	}
-	defer unlock()
+	defer clistate.Unlock(sMgr, m.Ui, m.Colorize())
 
 	// Unset the remote state
 	s = sMgr.State()
@@ -1399,21 +1404,6 @@ func init() {
 	backendlegacy.Init(Backends)
 }
 
-// simple wrapper to check for a state.Locker and always provide an unlock
-// function to defer.
-func lockState(s state.State, info string) (func() error, error) {
-	l, ok := s.(state.Locker)
-	if !ok {
-		return func() error { return nil }, nil
-	}
-
-	if err := l.Lock(info); err != nil {
-		return nil, err
-	}
-
-	return l.Unlock, nil
-}
-
 // errBackendInitRequired is the final error message shown when reinit
 // is required for some reason. The error message includes the reason.
 var errBackendInitRequired = errors.New(

command/meta_backend_migrate.go

@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	clistate "github.com/hashicorp/terraform/command/state"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 )
@@ -23,17 +24,17 @@ import (
 //
 // This will attempt to lock both states for the migration.
 func (m *Meta) backendMigrateState(opts *backendMigrateOpts) error {
-	unlockOne, err := lockState(opts.One, "migrate from")
+	err := clistate.Lock(opts.One, "migration source state", m.Ui, m.Colorize())
 	if err != nil {
-		return err
+		return fmt.Errorf("Error locking source state: %s", err)
 	}
-	defer unlockOne()
+	defer clistate.Unlock(opts.One, m.Ui, m.Colorize())
 
-	unlockTwo, err := lockState(opts.Two, "migrate to")
+	err = clistate.Lock(opts.Two, "migration destination state", m.Ui, m.Colorize())
 	if err != nil {
-		return err
+		return fmt.Errorf("Error locking destination state: %s", err)
 	}
-	defer unlockTwo()
+	defer clistate.Unlock(opts.Two, m.Ui, m.Colorize())
 
 	one := opts.One.State()
 	two := opts.Two.State()

command/taint.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"strings"
 
-	"github.com/hashicorp/terraform/state"
+	clistate "github.com/hashicorp/terraform/command/state"
 	"github.com/hashicorp/terraform/terraform"
 )
 
@@ -72,13 +72,14 @@ func (c *TaintCommand) Run(args []string) int {
 		return 1
 	}
 
-	if s, ok := st.(state.Locker); c.Meta.stateLock && ok {
-		if err := s.Lock("taint"); err != nil {
-			c.Ui.Error(fmt.Sprintf("Failed to lock state: %s", err))
+	if c.Meta.stateLock {
+		err := clistate.Lock(st, "taint", c.Ui, c.Colorize())
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error locking state: %s", err))
 			return 1
 		}
 
-		defer s.Unlock()
+		defer clistate.Unlock(st, c.Ui, c.Colorize())
 	}
 
 	// Get the actual state structure

command/unlock.go

@@ -124,7 +124,7 @@ func (c *UnlockCommand) Synopsis() string {
 }
 
 const outputUnlockSuccess = `
-[reset][bold][red]Terraform state has been successfully unlocked![reset][red]
+[reset][bold][green]Terraform state has been successfully unlocked![reset][green]
 
 The state has been unlocked, and Terraform commands should now be able to
 obtain a new lock on the remote state.

command/untaint.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"strings"
 
-	"github.com/hashicorp/terraform/state"
+	clistate "github.com/hashicorp/terraform/command/state"
 )
 
 // UntaintCommand is a cli.Command implementation that manually untaints
@@ -60,13 +60,14 @@ func (c *UntaintCommand) Run(args []string) int {
 		return 1
 	}
 
-	if s, ok := st.(state.Locker); c.Meta.stateLock && ok {
-		if err := s.Lock("untaint"); err != nil {
-			c.Ui.Error(fmt.Sprintf("Failed to lock state: %s", err))
+	if c.Meta.stateLock {
+		err := clistate.Lock(st, "untaint", c.Ui, c.Colorize())
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Error locking state: %s", err))
 			return 1
 		}
 
-		defer s.Unlock()
+		defer clistate.Unlock(st, c.Ui, c.Colorize())
 	}
 
 	// Get the actual state structure