terraform: only depose state if we're doing the destroy side

terraform/context_test.go

@@ -2787,6 +2787,60 @@ func TestContext2Apply_createBeforeDestroy(t *testing.T) {
 	}
 }
 
+func TestContext2Apply_createBeforeDestroyUpdate(t *testing.T) {
+	m := testModule(t, "apply-good-create-before-update")
+	p := testProvider("aws")
+	p.ApplyFn = testApplyFn
+	p.DiffFn = testDiffFn
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.bar": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "bar",
+							Attributes: map[string]string{
+								"foo": "bar",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+		State: state,
+	})
+
+	if p, err := ctx.Plan(nil); err != nil {
+		t.Fatalf("err: %s", err)
+	} else {
+		t.Logf(p.String())
+	}
+
+	state, err := ctx.Apply()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	mod := state.RootModule()
+	if len(mod.Resources) != 1 {
+		t.Fatalf("bad: %s", state)
+	}
+
+	actual := strings.TrimSpace(state.String())
+	expected := strings.TrimSpace(testTerraformApplyCreateBeforeUpdateStr)
+	if actual != expected {
+		t.Fatalf("bad: \n%s", actual)
+	}
+}
+
 func TestContext2Apply_minimal(t *testing.T) {
 	m := testModule(t, "apply-minimal")
 	p := testProvider("aws")

terraform/terraform_test.go

@@ -200,6 +200,13 @@ aws_instance.bar:
   type = aws_instance
 `
 
+const testTerraformApplyCreateBeforeUpdateStr = `
+aws_instance.bar:
+  ID = foo
+  foo = baz
+  type = aws_instance
+`
+
 const testTerraformApplyCancelStr = `
 aws_instance.foo:
   ID = foo

terraform/test-fixtures/apply-good-create-before-update/main.tf

@@ -0,0 +1,7 @@
+resource "aws_instance" "bar" {
+    foo = "baz"
+
+    lifecycle {
+        create_before_destroy = true
+    }
+}

terraform/transform_resource.go

@@ -256,6 +256,7 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 	var diffApply *InstanceDiff
 	var err error
 	var createNew, tainted bool
+	var createBeforeDestroyEnabled bool
 	seq.Nodes = append(seq.Nodes, &EvalOpFilter{
 		Ops: []walkOperation{walkApply},
 		Node: &EvalSequence{
@@ -285,7 +286,16 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 
 				&EvalIf{
 					If: func(ctx EvalContext) (bool, error) {
-						return n.Resource.Lifecycle.CreateBeforeDestroy, nil
+						destroy := false
+						if diffApply != nil {
+							destroy = diffApply.Destroy || diffApply.RequiresNew()
+						}
+
+						createBeforeDestroyEnabled =
+							n.Resource.Lifecycle.CreateBeforeDestroy &&
+								destroy
+
+						return createBeforeDestroyEnabled, nil
 					},
 					Node: &EvalDeposeState{
 						Name: n.stateId(),
@@ -361,12 +371,12 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 				},
 				&EvalIf{
 					If: func(ctx EvalContext) (bool, error) {
-						if n.Resource.Lifecycle.CreateBeforeDestroy {
+						if createBeforeDestroyEnabled {
 							tainted = err != nil
 						}
 
 						failure := tainted || err != nil
-						return n.Resource.Lifecycle.CreateBeforeDestroy && failure, nil
+						return createBeforeDestroyEnabled && failure, nil
 					},
 					Node: &EvalUndeposeState{
 						Name: n.stateId(),