From 4cd96ecfde09c51e93399dc7c204eaa0af93140c Mon Sep 17 00:00:00 2001
From: Paul Hinze <phinze@phinze.com>
Date: Tue, 15 Mar 2016 10:03:01 -0500
Subject: [PATCH] core: Don't filter ignore_changes on create

The ignore_changes diff filter was stripping out attributes on Create
but the diff was still making it down to the provider, so Create would
end up missing attributes, causing a full failure if any required
attributes were being ignored.

This should fix `ignore_changes` problems with Required attributes.

Refs #5627
---
 terraform/context_apply_test.go               | 41 +++++++++++++++++++
 terraform/eval_ignore_changes.go              |  6 +++
 .../apply-ignore-changes-create/main.tf       |  7 ++++
 3 files changed, 54 insertions(+)
 create mode 100644 terraform/test-fixtures/apply-ignore-changes-create/main.tf

diff --git a/terraform/context_apply_test.go b/terraform/context_apply_test.go
index a815f3928aaa..361f27379af0 100644
--- a/terraform/context_apply_test.go
+++ b/terraform/context_apply_test.go
@@ -4084,3 +4084,44 @@ aws_instance.ifailedprovisioners: (1 tainted)
 		t.Fatalf("expected state: \n%s\ngot: \n%s", expected, actual)
 	}
 }
+
+func TestContext2Apply_ignoreChangesCreate(t *testing.T) {
+	m := testModule(t, "apply-ignore-changes-create")
+	p := testProvider("aws")
+	p.ApplyFn = testApplyFn
+	p.DiffFn = testDiffFn
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	if p, err := ctx.Plan(); 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())
+	// Expect no changes from original state
+	expected := strings.TrimSpace(`
+aws_instance.foo:
+  ID = foo
+  required_field = set
+  type = aws_instance
+`)
+	if actual != expected {
+		t.Fatalf("bad: \n%s", actual)
+	}
+}
diff --git a/terraform/eval_ignore_changes.go b/terraform/eval_ignore_changes.go
index cc2261313714..3ae1d4995f19 100644
--- a/terraform/eval_ignore_changes.go
+++ b/terraform/eval_ignore_changes.go
@@ -22,6 +22,12 @@ func (n *EvalIgnoreChanges) Eval(ctx EvalContext) (interface{}, error) {
 	diff := *n.Diff
 	ignoreChanges := n.Resource.Lifecycle.IgnoreChanges
 
+	// If we're just creating the resource, we shouldn't alter the
+	// Diff at all
+	if diff.ChangeType() == DiffCreate {
+		return nil, nil
+	}
+
 	for _, ignoredName := range ignoreChanges {
 		for name := range diff.Attributes {
 			if strings.HasPrefix(name, ignoredName) {
diff --git a/terraform/test-fixtures/apply-ignore-changes-create/main.tf b/terraform/test-fixtures/apply-ignore-changes-create/main.tf
new file mode 100644
index 000000000000..d470660ec1cc
--- /dev/null
+++ b/terraform/test-fixtures/apply-ignore-changes-create/main.tf
@@ -0,0 +1,7 @@
+resource "aws_instance" "foo" {
+  required_field = "set"
+
+  lifecycle {
+    ignore_changes = ["required_field"]
+  }
+}