command/plan: add -destroy flag to plan a destroy

command/command_test.go

@@ -42,6 +42,21 @@ func testPlanFile(t *testing.T, plan *terraform.Plan) string {
 	return path
 }
 
+func testReadPlan(t *testing.T, path string) *terraform.Plan {
+	f, err := os.Open(path)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer f.Close()
+
+	p, err := terraform.ReadPlan(f)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return p
+}
+
 func testStateFile(t *testing.T, s *terraform.State) string {
 	path := testTempFile(t)
 

command/plan.go

@@ -20,10 +20,11 @@ type PlanCommand struct {
 }
 
 func (c *PlanCommand) Run(args []string) int {
-	var refresh bool
+	var destroy, refresh bool
 	var outPath, statePath string
 
 	cmdFlags := flag.NewFlagSet("plan", flag.ContinueOnError)
+	cmdFlags.BoolVar(&destroy, "destroy", false, "destroy")
 	cmdFlags.BoolVar(&refresh, "refresh", true, "refresh")
 	cmdFlags.StringVar(&outPath, "out", "", "path")
 	cmdFlags.StringVar(&statePath, "state", "", "path")
@@ -80,8 +81,9 @@ func (c *PlanCommand) Run(args []string) int {
 	}
 
 	plan, err := tf.Plan(&terraform.PlanOpts{
-		Config: b,
+		Config:  b,
-		State:  state,
+		Destroy: destroy,
+		State:   state,
 	})
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error running plan: %s", err))

command/plan_test.go

@@ -10,6 +10,43 @@ import (
 	"github.com/mitchellh/cli"
 )
 
+func TestPlan_destroy(t *testing.T) {
+	originalState := &terraform.State{
+		Resources: map[string]*terraform.ResourceState{
+			"test_instance.foo": &terraform.ResourceState{
+				ID:   "bar",
+				Type: "test_instance",
+			},
+		},
+	}
+
+	outPath := testTempFile(t)
+	statePath := testStateFile(t, originalState)
+
+	p := testProvider()
+	ui := new(cli.MockUi)
+	c := &PlanCommand{
+		TFConfig: testTFConfig(p),
+		Ui:       ui,
+	}
+
+	args := []string{
+		"-destroy",
+		"-out", outPath,
+		"-state", statePath,
+		testFixturePath("plan"),
+	}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter.String())
+	}
+
+	plan := testReadPlan(t, outPath)
+	for _, r := range plan.Diff.Resources {
+		if !r.Destroy {
+			t.Fatalf("bad: %#v", r)
+		}
+	}
+}
 func TestPlan_noState(t *testing.T) {
 	p := testProvider()
 	ui := new(cli.MockUi)

terraform/terraform.go

@@ -253,6 +253,8 @@ func (t *Terraform) planWalkFn(result *Plan, opts *PlanOpts) depgraph.WalkFunc {
 			if r.State.ID != "" {
 				log.Printf("[DEBUG] %s: Making for destroy", r.Id)
 				diff = &ResourceDiff{Destroy: true}
+			} else {
+				log.Printf("[DEBUG] %s: Not marking for destroy, no ID", r.Id)
 			}
 		} else if r.Config == nil {
 			log.Printf("[DEBUG] %s: Orphan, marking for destroy", r.Id)