Merge pull request #6597 from hashicorp/f-state-mv

command/state mv

command/command_test.go

@@ -224,21 +224,7 @@ func testProvider() *terraform.MockResourceProvider {
 }
 
 func testTempFile(t *testing.T) string {
-	tf, err := ioutil.TempFile("", "tf")
-	if err != nil {
-		t.Fatalf("err: %s", err)
-	}
-
-	result := tf.Name()
-
-	if err := tf.Close(); err != nil {
-		t.Fatalf("err: %s", err)
-	}
-	if err := os.Remove(result); err != nil {
-		t.Fatalf("err: %s", err)
-	}
-
-	return result
+	return filepath.Join(testTempDir(t), "state.tfstate")
 }
 
 func testTempDir(t *testing.T) string {

command/plan_test.go

@@ -108,6 +108,9 @@ func TestPlan_destroy(t *testing.T) {
 }
 
 func TestPlan_noState(t *testing.T) {
+	tmp, cwd := testCwd(t)
+	defer testFixCwd(t, tmp, cwd)
+
 	p := testProvider()
 	ui := new(cli.MockUi)
 	c := &PlanCommand{

command/state_meta.go

@@ -2,13 +2,46 @@ package command
 
 import (
 	"errors"
+	"fmt"
+	"time"
 
+	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 )
 
 // StateMeta is the meta struct that should be embedded in state subcommands.
 type StateMeta struct{}
 
+// State returns the state for this meta. This is different then Meta.State
+// in the way that backups are done. This configures backups to be timestamped
+// rather than just the original state path plus a backup path.
+func (c *StateMeta) State(m *Meta) (state.State, error) {
+	// Disable backups since we wrap it manually below
+	m.backupPath = "-"
+
+	// Get the state (shouldn't be wrapped in a backup)
+	s, err := m.State()
+	if err != nil {
+		return nil, err
+	}
+
+	// Determine the backup path. stateOutPath is set to the resulting
+	// file where state is written (cached in the case of remote state)
+	backupPath := fmt.Sprintf(
+		"%s.%d.%s",
+		m.stateOutPath,
+		time.Now().UTC().Unix(),
+		DefaultBackupExtension)
+
+	// Wrap it for backups
+	s = &state.BackupState{
+		Real: s,
+		Path: backupPath,
+	}
+
+	return s, nil
+}
+
 // filterInstance filters a single instance out of filter results.
 func (c *StateMeta) filterInstance(rs []*terraform.StateFilterResult) (*terraform.StateFilterResult, error) {
 	var result *terraform.StateFilterResult

command/state_mv.go

@@ -0,0 +1,179 @@
+package command
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/hashicorp/terraform/terraform"
+	"github.com/mitchellh/cli"
+)
+
+// StateMvCommand is a Command implementation that shows a single resource.
+type StateMvCommand struct {
+	Meta
+	StateMeta
+}
+
+func (c *StateMvCommand) Run(args []string) int {
+	args = c.Meta.process(args, true)
+
+	// We create two metas to track the two states
+	var meta1, meta2 Meta
+	cmdFlags := c.Meta.flagSet("state show")
+	cmdFlags.StringVar(&meta1.stateOutPath, "backup", "", "backup")
+	cmdFlags.StringVar(&meta1.statePath, "state", DefaultStateFilename, "path")
+	cmdFlags.StringVar(&meta2.stateOutPath, "backup-out", "", "backup")
+	cmdFlags.StringVar(&meta2.statePath, "state-out", "", "path")
+	if err := cmdFlags.Parse(args); err != nil {
+		return cli.RunResultHelp
+	}
+	args = cmdFlags.Args()
+	if len(args) != 2 {
+		c.Ui.Error("Exactly two arguments expected.\n")
+		return cli.RunResultHelp
+	}
+
+	// Copy the `-state` flag for output if we weren't given a custom one
+	if meta2.statePath == "" {
+		meta2.statePath = meta1.statePath
+	}
+
+	// Read the from state
+	stateFrom, err := c.StateMeta.State(&meta1)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateLoadingState, err))
+		return cli.RunResultHelp
+	}
+
+	stateFromReal := stateFrom.State()
+	if stateFromReal == nil {
+		c.Ui.Error(fmt.Sprintf(errStateNotFound))
+		return 1
+	}
+
+	// Read the destination state
+	stateTo := stateFrom
+	stateToReal := stateFromReal
+	if meta2.statePath != meta1.statePath {
+		stateTo, err = c.StateMeta.State(&meta2)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf(errStateLoadingState, err))
+			return cli.RunResultHelp
+		}
+
+		stateToReal = stateTo.State()
+		if stateToReal == nil {
+			stateToReal = terraform.NewState()
+		}
+	}
+
+	// Filter what we're moving
+	filter := &terraform.StateFilter{State: stateFromReal}
+	results, err := filter.Filter(args[0])
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateMv, err))
+		return cli.RunResultHelp
+	}
+	if len(results) == 0 {
+		c.Ui.Output(fmt.Sprintf("Item to move doesn't exist: %s", args[0]))
+		return 1
+	}
+
+	// Do the actual move
+	if err := stateFromReal.Remove(args[0]); err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateMv, err))
+		return 1
+	}
+
+	if err := stateToReal.Add(args[0], args[1], results[0].Value); err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateMv, err))
+		return 1
+	}
+
+	// Write the new state
+	if err := stateTo.WriteState(stateToReal); err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateMvPersist, err))
+		return 1
+	}
+
+	if err := stateTo.PersistState(); err != nil {
+		c.Ui.Error(fmt.Sprintf(errStateMvPersist, err))
+		return 1
+	}
+
+	// Write the old state if it is different
+	if stateTo != stateFrom {
+		if err := stateFrom.WriteState(stateFromReal); err != nil {
+			c.Ui.Error(fmt.Sprintf(errStateMvPersist, err))
+			return 1
+		}
+
+		if err := stateFrom.PersistState(); err != nil {
+			c.Ui.Error(fmt.Sprintf(errStateMvPersist, err))
+			return 1
+		}
+	}
+
+	c.Ui.Output(fmt.Sprintf(
+		"Moved %s to %s", args[0], args[1]))
+	return 0
+}
+
+func (c *StateMvCommand) Help() string {
+	helpText := `
+Usage: terraform state mv [options] ADDRESS ADDRESS
+
+  Move an item in the state to another location or to a completely different
+  state file.
+
+  This command is useful for module refactors (moving items into a module),
+  configuration refactors (moving items to a completely different or new
+  state file), or generally renaming of resources.
+
+  This command creates a timestamped backup of the state on every invocation.
+  This can't be disabled. Due to the destructive nature of this command,
+  the backup is ensured by Terraform for safety reasons.
+
+  If you're moving from one state file to a different state file, a backup
+  will be created for each state file.
+
+Options:
+
+  -backup=PATH        Path where Terraform should write the backup for the original
+                      state. This can't be disabled. If not set, Terraform
+                      will write it to the same path as the statefile with
+                      a backup extension.
+
+  -backup-out=PATH    Path where Terraform should write the backup for the destination
+                      state. This can't be disabled. If not set, Terraform
+                      will write it to the same path as the destination state
+                      file with a backup extension. This only needs
+                      to be specified if -state-out is set to a different path
+                      than -state.
+
+  -state=PATH         Path to a Terraform state file to use to look
+                      up Terraform-managed resources. By default it will
+                      use the state "terraform.tfstate" if it exists.
+
+  -state-out=PATH     Path to the destination state file to move the item
+                      to. This defaults to the same statefile. This will
+                      overwrite the destination state file.
+
+`
+	return strings.TrimSpace(helpText)
+}
+
+func (c *StateMvCommand) Synopsis() string {
+	return "Move an item in the state"
+}
+
+const errStateMv = `Error moving state: %[1]s
+
+Please ensure your addresses and state paths are valid. No
+state was persisted. Your existing states are untouched.`
+
+const errStateMvPersist = `Error saving the state: %s
+
+The state wasn't saved properly. If the error happening after a partial
+write occurred, a backup file will have been created. Otherwise, the state
+is in the same state it was when the operation started.`

command/state_mv_test.go

@@ -0,0 +1,289 @@
+package command
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/hashicorp/terraform/terraform"
+	"github.com/mitchellh/cli"
+)
+
+func TestStateMv(t *testing.T) {
+	state := &terraform.State{
+		Modules: []*terraform.ModuleState{
+			&terraform.ModuleState{
+				Path: []string{"root"},
+				Resources: map[string]*terraform.ResourceState{
+					"test_instance.foo": &terraform.ResourceState{
+						Type: "test_instance",
+						Primary: &terraform.InstanceState{
+							ID: "bar",
+							Attributes: map[string]string{
+								"foo": "value",
+								"bar": "value",
+							},
+						},
+					},
+
+					"test_instance.baz": &terraform.ResourceState{
+						Type: "test_instance",
+						Primary: &terraform.InstanceState{
+							ID: "foo",
+							Attributes: map[string]string{
+								"foo": "value",
+								"bar": "value",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	statePath := testStateFile(t, state)
+
+	p := testProvider()
+	ui := new(cli.MockUi)
+	c := &StateMvCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(p),
+			Ui:          ui,
+		},
+	}
+
+	args := []string{
+		"-state", statePath,
+		"test_instance.foo",
+		"test_instance.bar",
+	}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter.String())
+	}
+
+	// Test it is correct
+	testStateOutput(t, statePath, testStateMvOutput)
+
+	// Test we have backups
+	backups := testStateBackups(t, filepath.Dir(statePath))
+	if len(backups) != 1 {
+		t.Fatalf("bad: %#v", backups)
+	}
+	testStateOutput(t, backups[0], testStateMvOutputOriginal)
+}
+
+func TestStateMv_stateOutNew(t *testing.T) {
+	state := &terraform.State{
+		Modules: []*terraform.ModuleState{
+			&terraform.ModuleState{
+				Path: []string{"root"},
+				Resources: map[string]*terraform.ResourceState{
+					"test_instance.foo": &terraform.ResourceState{
+						Type: "test_instance",
+						Primary: &terraform.InstanceState{
+							ID: "bar",
+							Attributes: map[string]string{
+								"foo": "value",
+								"bar": "value",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	statePath := testStateFile(t, state)
+	stateOutPath := statePath + ".out"
+
+	p := testProvider()
+	ui := new(cli.MockUi)
+	c := &StateMvCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(p),
+			Ui:          ui,
+		},
+	}
+
+	args := []string{
+		"-state", statePath,
+		"-state-out", stateOutPath,
+		"test_instance.foo",
+		"test_instance.bar",
+	}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter.String())
+	}
+
+	// Test it is correct
+	testStateOutput(t, stateOutPath, testStateMvOutput_stateOut)
+	testStateOutput(t, statePath, testStateMvOutput_stateOutSrc)
+
+	// Test we have backups
+	backups := testStateBackups(t, filepath.Dir(statePath))
+	if len(backups) != 1 {
+		t.Fatalf("bad: %#v", backups)
+	}
+	testStateOutput(t, backups[0], testStateMvOutput_stateOutOriginal)
+}
+
+func TestStateMv_stateOutExisting(t *testing.T) {
+	stateSrc := &terraform.State{
+		Modules: []*terraform.ModuleState{
+			&terraform.ModuleState{
+				Path: []string{"root"},
+				Resources: map[string]*terraform.ResourceState{
+					"test_instance.foo": &terraform.ResourceState{
+						Type: "test_instance",
+						Primary: &terraform.InstanceState{
+							ID: "bar",
+							Attributes: map[string]string{
+								"foo": "value",
+								"bar": "value",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	statePath := testStateFile(t, stateSrc)
+
+	stateDst := &terraform.State{
+		Modules: []*terraform.ModuleState{
+			&terraform.ModuleState{
+				Path: []string{"root"},
+				Resources: map[string]*terraform.ResourceState{
+					"test_instance.qux": &terraform.ResourceState{
+						Type: "test_instance",
+						Primary: &terraform.InstanceState{
+							ID: "bar",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	stateOutPath := testStateFile(t, stateDst)
+
+	p := testProvider()
+	ui := new(cli.MockUi)
+	c := &StateMvCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(p),
+			Ui:          ui,
+		},
+	}
+
+	args := []string{
+		"-state", statePath,
+		"-state-out", stateOutPath,
+		"test_instance.foo",
+		"test_instance.bar",
+	}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter.String())
+	}
+
+	// Test it is correct
+	testStateOutput(t, stateOutPath, testStateMvExisting_stateDst)
+	testStateOutput(t, statePath, testStateMvExisting_stateSrc)
+
+	// Test we have backups
+	backups := testStateBackups(t, filepath.Dir(statePath))
+	if len(backups) != 1 {
+		t.Fatalf("bad: %#v", backups)
+	}
+	testStateOutput(t, backups[0], testStateMvExisting_stateSrcOriginal)
+
+	backups = testStateBackups(t, filepath.Dir(stateOutPath))
+	if len(backups) != 1 {
+		t.Fatalf("bad: %#v", backups)
+	}
+	testStateOutput(t, backups[0], testStateMvExisting_stateDstOriginal)
+}
+
+func TestStateMv_noState(t *testing.T) {
+	tmp, cwd := testCwd(t)
+	defer testFixCwd(t, tmp, cwd)
+
+	p := testProvider()
+	ui := new(cli.MockUi)
+	c := &StateMvCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(p),
+			Ui:          ui,
+		},
+	}
+
+	args := []string{"from", "to"}
+	if code := c.Run(args); code != 1 {
+		t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter.String())
+	}
+}
+
+const testStateMvOutputOriginal = `
+test_instance.baz:
+  ID = foo
+  bar = value
+  foo = value
+test_instance.foo:
+  ID = bar
+  bar = value
+  foo = value
+`
+
+const testStateMvOutput = `
+test_instance.bar:
+  ID = bar
+  bar = value
+  foo = value
+test_instance.baz:
+  ID = foo
+  bar = value
+  foo = value
+`
+
+const testStateMvOutput_stateOut = `
+test_instance.bar:
+  ID = bar
+  bar = value
+  foo = value
+`
+
+const testStateMvOutput_stateOutSrc = `
+<no state>
+`
+
+const testStateMvOutput_stateOutOriginal = `
+test_instance.foo:
+  ID = bar
+  bar = value
+  foo = value
+`
+
+const testStateMvExisting_stateSrc = `
+<no state>
+`
+
+const testStateMvExisting_stateDst = `
+test_instance.bar:
+  ID = bar
+  bar = value
+  foo = value
+test_instance.qux:
+  ID = bar
+`
+
+const testStateMvExisting_stateSrcOriginal = `
+test_instance.foo:
+  ID = bar
+  bar = value
+  foo = value
+`
+
+const testStateMvExisting_stateDstOriginal = `
+test_instance.qux:
+  ID = bar
+`

command/state_show.go

@@ -26,7 +26,7 @@ func (c *StateShowCommand) Run(args []string) int {
 	}
 	args = cmdFlags.Args()
 
-	state, err := c.State()
+	state, err := c.Meta.State()
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf(errStateLoadingState, err))
 		return cli.RunResultHelp

command/state_test.go

@@ -0,0 +1,22 @@
+package command
+
+import (
+	"path/filepath"
+	"sort"
+	"testing"
+)
+
+// testStateBackups returns the list of backups in order of creation
+// (oldest first) in the given directory.
+func testStateBackups(t *testing.T, dir string) []string {
+	// Find all the backups
+	list, err := filepath.Glob(filepath.Join(dir, "*"+DefaultBackupExtension))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Sort them which will put them naturally in the right order
+	sort.Strings(list)
+
+	return list
+}

terraform/resource_address.go

@@ -52,11 +52,15 @@ func (r *ResourceAddress) String() string {
 
 	if r.Name != "" {
 		name := r.Name
-		switch r.InstanceType {
-		case TypeDeposed:
-			name += ".deposed"
-		case TypeTainted:
-			name += ".tainted"
+		if r.InstanceTypeSet {
+			switch r.InstanceType {
+			case TypePrimary:
+				name += ".primary"
+			case TypeDeposed:
+				name += ".deposed"
+			case TypeTainted:
+				name += ".tainted"
+			}
 		}
 
 		if r.Index >= 0 {

terraform/resource_address_test.go

@@ -50,7 +50,7 @@ func TestParseResourceAddress(t *testing.T) {
 				InstanceTypeSet: true,
 				Index:           2,
 			},
-			"aws_instance.foo[2]",
+			"",
 		},
 		"tainted": {
 			"aws_instance.foo.tainted",

terraform/state.go

@@ -417,12 +417,8 @@ func (s *State) init() {
 	if s.Version == 0 {
 		s.Version = StateVersion
 	}
-	if len(s.Modules) == 0 {
-		root := &ModuleState{
-			Path: rootModulePath,
-		}
-		root.init()
-		s.Modules = []*ModuleState{root}
+	if s.ModuleByPath(rootModulePath) == nil {
+		s.AddModule(rootModulePath)
 	}
 }
 
@@ -677,11 +673,13 @@ func (m *ModuleState) deepcopy() *ModuleState {
 		return nil
 	}
 	n := &ModuleState{
-		Path:      make([]string, len(m.Path)),
-		Outputs:   make(map[string]interface{}, len(m.Outputs)),
-		Resources: make(map[string]*ResourceState, len(m.Resources)),
+		Path:         make([]string, len(m.Path)),
+		Outputs:      make(map[string]interface{}, len(m.Outputs)),
+		Resources:    make(map[string]*ResourceState, len(m.Resources)),
+		Dependencies: make([]string, len(m.Dependencies)),
 	}
 	copy(n.Path, m.Path)
+	copy(n.Dependencies, m.Dependencies)
 	for k, v := range m.Outputs {
 		n.Outputs[k] = v
 	}

terraform/state_add.go

@@ -0,0 +1,315 @@
+package terraform
+
+import (
+	"fmt"
+)
+
+// Add adds the item in the state at the given address.
+//
+// The item can be a ModuleState, ResourceState, or InstanceState. Depending
+// on the item type, the address may or may not be valid. For example, a
+// module cannot be moved to a resource address, however a resource can be
+// moved to a module address (it retains the same name, under that resource).
+//
+// The full semantics of Add:
+//
+//                         ┌───────────────────────┬───────────────────────┬───────────────────────┐
+//                         │    Module Address     │   Resource Address    │   Instance Address    │
+// ┌───────────────────────┼───────────────────────┼───────────────────────┼───────────────────────┤
+// │      ModuleState      │           ✓           │           x           │           x           │
+// ├───────────────────────┼───────────────────────┼───────────────────────┼───────────────────────┤
+// │     ResourceState     │           ✓           │           ✓           │        maybe*         │
+// ├───────────────────────┼───────────────────────┼───────────────────────┼───────────────────────┤
+// │    Instance State     │           ✓           │           ✓           │           ✓           │
+// └───────────────────────┴───────────────────────┴───────────────────────┴───────────────────────┘
+//
+// *maybe - Resources can be added at an instance address only if the resource
+//          represents a single instance (primary). Example:
+//          "aws_instance.foo" can be moved to "aws_instance.bar.tainted"
+//
+func (s *State) Add(fromAddrRaw string, toAddrRaw string, raw interface{}) error {
+	// Parse the address
+	toAddr, err := ParseResourceAddress(toAddrRaw)
+	if err != nil {
+		return err
+	}
+
+	// Parse the from address
+	fromAddr, err := ParseResourceAddress(fromAddrRaw)
+	if err != nil {
+		return err
+	}
+
+	// Determine the types
+	from := detectValueAddLoc(raw)
+	to := detectAddrAddLoc(toAddr)
+
+	// Find the function to do this
+	fromMap, ok := stateAddFuncs[from]
+	if !ok {
+		return fmt.Errorf("invalid source to add to state: %T", raw)
+	}
+	f, ok := fromMap[to]
+	if !ok {
+		return fmt.Errorf("invalid destination: %s (%d)", toAddr, to)
+	}
+
+	// Call the migrator
+	if err := f(s, fromAddr, toAddr, raw); err != nil {
+		return err
+	}
+
+	// Prune the state
+	s.prune()
+	return nil
+}
+
+func stateAddFunc_Module_Module(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
+	src := raw.(*ModuleState).deepcopy()
+
+	// If the target module exists, it is an error
+	path := append([]string{"root"}, addr.Path...)
+	if s.ModuleByPath(path) != nil {
+		return fmt.Errorf("module target is not empty: %s", addr)
+	}
+
+	// Create it and copy our outputs and dependencies
+	mod := s.AddModule(path)
+	mod.Outputs = src.Outputs
+	mod.Dependencies = src.Dependencies
+
+	// Go through the resources perform an add for each of those
+	for k, v := range src.Resources {
+		resourceKey, err := ParseResourceStateKey(k)
+		if err != nil {
+			return err
+		}
+
+		// Update the resource address for this
+		addrCopy := *addr
+		addrCopy.Type = resourceKey.Type
+		addrCopy.Name = resourceKey.Name
+		addrCopy.Index = resourceKey.Index
+
+		// Perform an add
+		if err := s.Add(fromAddr.String(), addrCopy.String(), v); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func stateAddFunc_Resource_Module(
+	s *State, from, to *ResourceAddress, raw interface{}) error {
+	// Build the more specific to addr
+	addr := *to
+	addr.Type = from.Type
+	addr.Name = from.Name
+
+	return s.Add(from.String(), addr.String(), raw)
+}
+
+func stateAddFunc_Resource_Resource(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
+	src := raw.(*ResourceState).deepcopy()
+
+	// Initialize the resource
+	resourceRaw, exists := stateAddInitAddr(s, addr)
+	if exists {
+		return fmt.Errorf("resource exists and not empty: %s", addr)
+	}
+	resource := resourceRaw.(*ResourceState)
+	resource.Type = src.Type
+	resource.Dependencies = src.Dependencies
+	resource.Provider = src.Provider
+
+	// Move the primary
+	if src.Primary != nil {
+		addrCopy := *addr
+		addrCopy.InstanceType = TypePrimary
+		addrCopy.InstanceTypeSet = true
+		if err := s.Add(fromAddr.String(), addrCopy.String(), src.Primary); err != nil {
+			return err
+		}
+	}
+
+	// Move all tainted
+	if len(src.Tainted) > 0 {
+		resource.Tainted = src.Tainted
+	}
+
+	// Move all deposed
+	if len(src.Deposed) > 0 {
+		resource.Deposed = src.Deposed
+	}
+
+	return nil
+}
+
+func stateAddFunc_Instance_Instance(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
+	src := raw.(*InstanceState).deepcopy()
+
+	// Create the instance
+	instanceRaw, _ := stateAddInitAddr(s, addr)
+	instance := instanceRaw.(*InstanceState)
+
+	// Set it
+	*instance = *src
+
+	return nil
+}
+
+func stateAddFunc_Instance_Module(
+	s *State, from, to *ResourceAddress, raw interface{}) error {
+	addr := *to
+	addr.Type = from.Type
+	addr.Name = from.Name
+
+	return s.Add(from.String(), addr.String(), raw)
+}
+
+func stateAddFunc_Instance_Resource(
+	s *State, from, to *ResourceAddress, raw interface{}) error {
+	addr := *to
+	addr.InstanceType = TypePrimary
+	addr.InstanceTypeSet = true
+
+	return s.Add(from.String(), addr.String(), raw)
+}
+
+// stateAddFunc is the type of function for adding an item to a state
+type stateAddFunc func(s *State, from, to *ResourceAddress, item interface{}) error
+
+// stateAddFuncs has the full matrix mapping of the state adders.
+var stateAddFuncs map[stateAddLoc]map[stateAddLoc]stateAddFunc
+
+func init() {
+	stateAddFuncs = map[stateAddLoc]map[stateAddLoc]stateAddFunc{
+		stateAddModule: {
+			stateAddModule: stateAddFunc_Module_Module,
+		},
+		stateAddResource: {
+			stateAddModule:   stateAddFunc_Resource_Module,
+			stateAddResource: stateAddFunc_Resource_Resource,
+		},
+		stateAddInstance: {
+			stateAddInstance: stateAddFunc_Instance_Instance,
+			stateAddModule:   stateAddFunc_Instance_Module,
+			stateAddResource: stateAddFunc_Instance_Resource,
+		},
+	}
+}
+
+// stateAddLoc is an enum to represent the location where state is being
+// moved from/to. We use this for quick lookups in a function map.
+type stateAddLoc uint
+
+const (
+	stateAddInvalid stateAddLoc = iota
+	stateAddModule
+	stateAddResource
+	stateAddInstance
+)
+
+// detectAddrAddLoc detects the state type for the given address. This
+// function is specifically not unit tested since we consider the State.Add
+// functionality to be comprehensive enough to cover this.
+func detectAddrAddLoc(addr *ResourceAddress) stateAddLoc {
+	if addr.Name == "" {
+		return stateAddModule
+	}
+
+	if !addr.InstanceTypeSet {
+		return stateAddResource
+	}
+
+	return stateAddInstance
+}
+
+// detectValueAddLoc determines the stateAddLoc value from the raw value
+// that is some State structure.
+func detectValueAddLoc(raw interface{}) stateAddLoc {
+	switch raw.(type) {
+	case *ModuleState:
+		return stateAddModule
+	case *ResourceState:
+		return stateAddResource
+	case *InstanceState:
+		return stateAddInstance
+	default:
+		return stateAddInvalid
+	}
+}
+
+// stateAddInitAddr takes a ResourceAddress and creates the non-existing
+// resources up to that point, returning the empty (or existing) interface
+// at that address.
+func stateAddInitAddr(s *State, addr *ResourceAddress) (interface{}, bool) {
+	addType := detectAddrAddLoc(addr)
+
+	// Get the module
+	path := append([]string{"root"}, addr.Path...)
+	exists := true
+	mod := s.ModuleByPath(path)
+	if mod == nil {
+		mod = s.AddModule(path)
+		exists = false
+	}
+	if addType == stateAddModule {
+		return mod, exists
+	}
+
+	// Add the resource
+	resourceKey := (&ResourceStateKey{
+		Name:  addr.Name,
+		Type:  addr.Type,
+		Index: addr.Index,
+	}).String()
+	exists = true
+	resource, ok := mod.Resources[resourceKey]
+	if !ok {
+		resource = &ResourceState{Type: addr.Type}
+		resource.init()
+		mod.Resources[resourceKey] = resource
+		exists = false
+	}
+	if addType == stateAddResource {
+		return resource, exists
+	}
+
+	// Get the instance
+	exists = true
+	instance := &InstanceState{}
+	switch addr.InstanceType {
+	case TypePrimary:
+		if v := resource.Primary; v != nil {
+			instance = resource.Primary
+		} else {
+			exists = false
+		}
+	case TypeTainted:
+		idx := addr.Index
+		if addr.Index < 0 {
+			idx = 0
+		}
+		if len(resource.Tainted) > idx {
+			instance = resource.Tainted[idx]
+		} else {
+			resource.Tainted = append(resource.Tainted, instance)
+			exists = false
+		}
+	case TypeDeposed:
+		idx := addr.Index
+		if addr.Index < 0 {
+			idx = 0
+		}
+		if len(resource.Deposed) > idx {
+			instance = resource.Deposed[idx]
+		} else {
+			resource.Deposed = append(resource.Deposed, instance)
+			exists = false
+		}
+	}
+
+	return instance, exists
+}

terraform/state_add_test.go

@@ -0,0 +1,422 @@
+package terraform
+
+import (
+	"testing"
+)
+
+func TestStateAdd(t *testing.T) {
+	cases := map[string]struct {
+		Err      bool
+		From, To string
+		Value    interface{}
+		One, Two *State
+	}{
+		"ModuleState => Module Addr (new)": {
+			false,
+			"",
+			"module.foo",
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"test_instance.foo": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"test_instance.bar": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo"},
+						Resources: map[string]*ResourceState{
+							"test_instance.foo": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+
+							"test_instance.bar": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ModuleState => Nested Module Addr (new)": {
+			false,
+			"",
+			"module.foo.module.bar",
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"test_instance.foo": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"test_instance.bar": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo", "bar"},
+						Resources: map[string]*ResourceState{
+							"test_instance.foo": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+
+							"test_instance.bar": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ModuleState w/ outputs and deps => Module Addr (new)": {
+			false,
+			"",
+			"module.foo",
+			&ModuleState{
+				Path: rootModulePath,
+				Outputs: map[string]interface{}{
+					"foo": "bar",
+				},
+				Dependencies: []string{"foo"},
+				Resources: map[string]*ResourceState{
+					"test_instance.foo": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"test_instance.bar": &ResourceState{
+						Type: "test_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo"},
+						Outputs: map[string]interface{}{
+							"foo": "bar",
+						},
+						Dependencies: []string{"foo"},
+						Resources: map[string]*ResourceState{
+							"test_instance.foo": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+
+							"test_instance.bar": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ModuleState => Module Addr (existing)": {
+			true,
+			"",
+			"module.foo",
+			&ModuleState{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo"},
+						Resources: map[string]*ResourceState{
+							"test_instance.baz": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+			nil,
+		},
+
+		"ResourceState => Resource Addr (new)": {
+			false,
+			"aws_instance.bar",
+			"aws_instance.foo",
+			&ResourceState{
+				Type: "test_instance",
+				Primary: &InstanceState{
+					ID: "foo",
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.foo": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ResourceState w/ deps, provider => Resource Addr (new)": {
+			false,
+			"aws_instance.bar",
+			"aws_instance.foo",
+			&ResourceState{
+				Type:         "test_instance",
+				Provider:     "foo",
+				Dependencies: []string{"bar"},
+				Primary: &InstanceState{
+					ID: "foo",
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.foo": &ResourceState{
+								Type:         "test_instance",
+								Provider:     "foo",
+								Dependencies: []string{"bar"},
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ResourceState w/ tainted => Resource Addr (new)": {
+			false,
+			"aws_instance.bar",
+			"aws_instance.foo",
+			&ResourceState{
+				Type: "test_instance",
+				Tainted: []*InstanceState{
+					&InstanceState{
+						ID: "foo",
+					},
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.foo": &ResourceState{
+								Type:    "test_instance",
+								Primary: &InstanceState{},
+								Tainted: []*InstanceState{
+									&InstanceState{
+										ID: "foo",
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"ResourceState => Resource Addr (existing)": {
+			true,
+			"aws_instance.bar",
+			"aws_instance.foo",
+			&ResourceState{
+				Type: "test_instance",
+				Primary: &InstanceState{
+					ID: "foo",
+				},
+			},
+
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.foo": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+			nil,
+		},
+
+		"ResourceState => Module (new)": {
+			false,
+			"aws_instance.bar",
+			"module.foo",
+			&ResourceState{
+				Type: "test_instance",
+				Primary: &InstanceState{
+					ID: "foo",
+				},
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.bar": &ResourceState{
+								Type: "test_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"InstanceState => Resource (new)": {
+			false,
+			"aws_instance.bar.primary",
+			"aws_instance.baz",
+			&InstanceState{
+				ID: "foo",
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.baz": &ResourceState{
+								Type: "aws_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+
+		"InstanceState => Module (new)": {
+			false,
+			"aws_instance.bar.primary",
+			"module.foo",
+			&InstanceState{
+				ID: "foo",
+			},
+
+			&State{},
+			&State{
+				Modules: []*ModuleState{
+					&ModuleState{
+						Path: []string{"root", "foo"},
+						Resources: map[string]*ResourceState{
+							"aws_instance.bar": &ResourceState{
+								Type: "aws_instance",
+								Primary: &InstanceState{
+									ID: "foo",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for k, tc := range cases {
+		// Make sure they're both initialized as normal
+		tc.One.init()
+		if tc.Two != nil {
+			tc.Two.init()
+		}
+
+		// Add the value
+		err := tc.One.Add(tc.From, tc.To, tc.Value)
+		if (err != nil) != tc.Err {
+			t.Fatalf("bad: %s\n\n%s", k, err)
+		}
+		if tc.Err {
+			continue
+		}
+
+		// Prune them both to be sure
+		tc.One.prune()
+		tc.Two.prune()
+
+		// Verify equality
+		if !tc.One.Equal(tc.Two) {
+			t.Fatalf("Bad: %s\n\n%#v\n\n%#v", k, tc.One, tc.Two)
+			//t.Fatalf("Bad: %s\n\n%s\n\n%s", k, tc.One.String(), tc.Two.String())
+		}
+	}
+}

terraform/state_filter.go

@@ -124,7 +124,7 @@ func (f *StateFilter) filterSingle(a *ResourceAddress) []*StateFilterResult {
 				// Add the instances
 				if r.Primary != nil {
 					addr.InstanceType = TypePrimary
-					addr.InstanceTypeSet = true
+					addr.InstanceTypeSet = false
 					results = append(results, &StateFilterResult{
 						Path:    addr.Path,
 						Address: addr.String(),

website/source/docs/commands/state/mv.html.md

@@ -0,0 +1,89 @@
+---
+layout: "commands-state"
+page_title: "Command: state mv"
+sidebar_current: "docs-state-sub-mv"
+description: |-
+  The `terraform state rm` command removes items from the Terraform state.
+---
+
+# Command: state mv
+
+The `terraform state mv` command is used to move items in a
+[Terraform state](/docs/state/index.html). This command can move
+single resources, single instances of a resource, entire modules, and more.
+This command can also move items to a completely different state file,
+enabling efficient refactoring.
+
+## Usage
+
+Usage: `terraform state mv [options] SOURCE DESTINATION`
+
+This command will move an item matched by the address given to the
+destination address. This command can also move to a destination address
+in a completely different state file.
+
+This can be used for simple resource renaming, moving items to and from
+a module, moving entire modules, and more. And because this command can also
+move data to a completely new state, it can also be used for refactoring
+one configuration into multiple separately managed Terraform configurations.
+
+This command will output a backup copy of the state prior to saving any
+changes. The backup cannot be disabled. Due to the destructive nature
+of this command, backups are required.
+
+If you're moving an item to a different state file, a backup will be created
+for each state file.
+
+This command requires a source and destination address of the item to move.
+Addresses are
+in [resource addressing format](/docs/commands/state/addressing.html).
+
+The command-line flags are all optional. The list of available flags are:
+
+* `-backup=path` - Path to a backup file Defaults to the state path plus
+                   a timestamp with the ".backup" extension.
+
+* `-backup-out=path` - Path to the backup file for the output state.
+                       This is only necessary if `-state-out` is specified.
+
+* `-state=path` - Path to the state file. Defaults to "terraform.tfstate".
+
+* `-state-out=path` - Path to the state file to write to. If this isn't specified
+                      the state specified by `-state` will be used. This can be
+                      a new or existing path.
+
+## Example: Rename a Resource
+
+The example below renames a single resource:
+
+```
+$ terraform state mv aws_instance.foo aws_instance.bar
+```
+
+## Example: Move a Resource Into a Module
+
+The example below moves a resource into a module. The module will be
+created if it doesn't exist.
+
+```
+$ terraform state mv aws_instance.foo module.web
+```
+
+## Example: Move a Module Into a Module
+
+The example below moves a module into another module.
+
+```
+$ terraform state mv module.foo module.parent.module.foo
+```
+
+## Example: Move a Module to Another State
+
+The example below moves a module into another state file. This removes
+the module from the original state file and adds it to the destination.
+The source and destination are the same meaning we're keeping the same name.
+
+```
+$ terraform state mv -state-out=other.tfstate \
+    module.web module.web
+```

website/source/layouts/commands-state.erb

@@ -21,6 +21,14 @@
 							<a href="/docs/commands/state/list.html">list</a>
 						</li>
 
+						<li<%= sidebar_current("docs-state-sub-mv") %>>
+							<a href="/docs/commands/state/mv.html">mv</a>
+						</li>
+
+						<li<%= sidebar_current("docs-state-sub-rm") %>>
+							<a href="/docs/commands/state/rm.html">rm</a>
+						</li>
+
 						<li<%= sidebar_current("docs-state-sub-show") %>>
 							<a href="/docs/commands/state/show.html">show</a>
 						</li>