terraform: destroy orphans

terraform/diff.go

@@ -99,7 +99,11 @@ func (d *Diff) String() string {
 		rdiff := d.Resources[name]
 
 		crud := "UPDATE"
-		if rdiff.RequiresNew() {
+		if rdiff.RequiresNew() && rdiff.Destroy {
+			crud = "DESTROY/CREATE"
+		} else if rdiff.Destroy {
+			crud = "DESTROY"
+		} else if rdiff.RequiresNew() {
 			crud = "CREATE"
 		}
 
@@ -179,7 +183,7 @@ func (d *ResourceDiff) Empty() bool {
 		return true
 	}
 
-	return len(d.Attributes) == 0
+	return !d.Destroy && len(d.Attributes) == 0
 }
 
 // RequiresNew returns true if the diff requires the creation of a new

terraform/terraform.go

@@ -225,11 +225,19 @@ func (t *Terraform) planWalkFn(
 	result.init()
 
 	cb := func(r *Resource) (map[string]string, error) {
+		var diff *ResourceDiff
+
+		if r.Config == nil {
+			// This is an orphan (no config), so we mark it to be destroyed
+			diff = &ResourceDiff{Destroy: true}
+		} else {
 			// Get a diff from the newest state
-		diff, err := r.Provider.Diff(r.State, r.Config)
+			var err error
+			diff, err = r.Provider.Diff(r.State, r.Config)
 			if err != nil {
 				return nil, err
 			}
+		}
 
 		l.Lock()
 		if !diff.Empty() {
@@ -304,7 +312,7 @@ func (t *Terraform) genericWalkFn(
 		}
 
 		// Make sure that at least some resource configuration is set
-		if rn.Resource.Config == nil {
+		if rn.Resource.Config == nil && !rn.Orphan {
 			if rn.Config == nil {
 				rn.Resource.Config = new(ResourceConfig)
 			} else {

terraform/terraform_test.go

@@ -161,6 +161,31 @@ func TestTerraformPlan_computed(t *testing.T) {
 	}
 }
 
+func TestTerraformPlan_orphan(t *testing.T) {
+	c := testConfig(t, "plan-orphan")
+	tf := testTerraform2(t, nil)
+
+	s := &State{
+		Resources: map[string]*ResourceState{
+			"aws_instance.baz": &ResourceState{
+				ID:   "bar",
+				Type: "aws_instance",
+			},
+		},
+	}
+
+	plan, err := tf.Plan(c, s, nil)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(plan.String())
+	expected := strings.TrimSpace(testTerraformPlanOrphanStr)
+	if actual != expected {
+		t.Fatalf("bad:\n%s", actual)
+	}
+}
+
 func TestTerraformPlan_state(t *testing.T) {
 	c := testConfig(t, "plan-good")
 	tf := testTerraform2(t, nil)
@@ -495,6 +520,20 @@ STATE:
 <no state>
 `
 
+const testTerraformPlanOrphanStr = `
+DIFF:
+
+DESTROY: aws_instance.baz
+UPDATE: aws_instance.foo
+  num:  "" => "2"
+  type: "" => "aws_instance"
+
+STATE:
+
+aws_instance.baz:
+  ID = bar
+`
+
 const testTerraformPlanStateStr = `
 DIFF:
 

terraform/test-fixtures/plan-orphan/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "foo" {
+    num = "2"
+}