command: backup stuff works better

command/meta.go

@@ -40,19 +40,22 @@ type Meta struct {
 	color bool
 	oldUi cli.Ui
 
+	// The fields below are expected to be set by the command via
+	// command line flags. See the Apply command for an example.
+	//
 	// statePath is the path to the state file. If this is empty, then
 	// no state will be loaded. It is also okay for this to be a path to
 	// a file that doesn't exist; it is assumed that this means that there
 	// is simply no state.
-	statePath string
-
+	//
 	// stateOutPath is used to override the output path for the state.
 	// If not provided, the StatePath is used causing the old state to
 	// be overriden.
-	stateOutPath string
-
+	//
 	// backupPath is used to backup the state file before writing a modified
 	// version. It defaults to stateOutPath + DefaultBackupExtention
+	statePath    string
+	stateOutPath string
 	backupPath   string
 }
 
@@ -123,12 +126,10 @@ func (m *Meta) Context(copts contextOpts) (*terraform.Context, bool, error) {
 	}
 
 	// Store the loaded state
-	state, statePath, err := State(m.statePath)
+	state, err := m.State()
 	if err != nil {
 		return nil, false, err
 	}
-	m.state = state
-	m.stateOutPath = statePath
 
 	// Load the root module
 	mod, err := module.NewTreeModule("", copts.Path)
@@ -173,12 +174,17 @@ func (m *Meta) State() (state.State, error) {
 		return m.state, nil
 	}
 
-	state, _, err := State(m.statePath)
+	state, statePath, err := State(&StateOpts{
+		LocalPath:    m.statePath,
+		LocalPathOut: m.stateOutPath,
+		BackupPath:   m.backupPath,
+	})
 	if err != nil {
 		return nil, err
 	}
 
 	m.state = state
+	m.stateOutPath = statePath
 	return state, nil
 }
 

command/state.go

@@ -11,13 +11,28 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
+// StateOpts are options to get the state for a command.
+type StateOpts struct {
+	// LocalPath is the path where the state is stored locally.
+	//
+	// LocalPathOut is the path where the local state will be saved. If this
+	// isn't set, it will be saved back to LocalPath.
+	LocalPath    string
+	LocalPathOut string
+
+	// BackupPath is the path where the backup will be placed. If not set,
+	// it is assumed to be the path where the state is stored locally
+	// plus the DefaultBackupExtension.
+	BackupPath string
+}
+
 // State returns the proper state.State implementation to represent the
 // current environment.
 //
 // localPath is the path to where state would be if stored locally.
 // dataDir is the path to the local data directory where the remote state
 // cache would be stored.
-func State(localPath string) (state.State, string, error) {
+func State(opts *StateOpts) (state.State, string, error) {
 	var result state.State
 	var resultPath string
 
@@ -33,8 +48,11 @@ func State(localPath string) (state.State, string, error) {
 	}
 
 	// Do we have a local state?
-	if localPath != "" {
-		local := &state.LocalState{Path: localPath}
+	if opts.LocalPath != "" {
+		local := &state.LocalState{
+			Path:    opts.LocalPath,
+			PathOut: opts.LocalPathOut,
+		}
 		err := local.RefreshState()
 		if err != nil {
 			isNotExist := false
@@ -51,7 +69,7 @@ func State(localPath string) (state.State, string, error) {
 				// We already have a remote state... that is an error.
 				return nil, "", fmt.Errorf(
 					"Remote state found, but state file '%s' also present.",
-					localPath)
+					opts.LocalPath)
 			}
 		}
 		if err != nil {
@@ -60,14 +78,22 @@ func State(localPath string) (state.State, string, error) {
 		}
 
 		result = local
-		resultPath = localPath
+		resultPath = opts.LocalPath
+		if opts.LocalPathOut != "" {
+			resultPath = opts.LocalPathOut
+		}
 	}
 
 	// If we have a result, make sure to back it up
 	if result != nil {
+		backupPath := resultPath + DefaultBackupExtention
+		if opts.BackupPath != "" {
+			backupPath = opts.BackupPath
+		}
+
 		result = &state.BackupState{
 			Real: result,
-			Path: resultPath + DefaultBackupExtention,
+			Path: backupPath,
 		}
 	}