resource/aws_route53_record: Suppress uppercase alias name diff

aws/resource_aws_route53_record.go

@@ -101,6 +101,12 @@ func resourceAwsRoute53Record() *schema.Resource {
 							Type:      schema.TypeString,
 							Required:  true,
 							StateFunc: normalizeAwsAliasName,
+							DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+								if strings.ToLower(old) == strings.ToLower(new) {
+									return true
+								}
+								return false
+							},
 						},
 
 						"evaluate_target_health": {
@@ -898,11 +904,11 @@ func nilString(s string) *string {
 
 func normalizeAwsAliasName(alias interface{}) string {
 	input := alias.(string)
-	if strings.HasPrefix(input, "dualstack.") {
-		return strings.Replace(input, "dualstack.", "", -1)
+	output := strings.ToLower(input)
+	if strings.HasPrefix(output, "dualstack.") {
+		output = strings.TrimLeft(output, "dualstack.")
 	}
-
-	return strings.TrimRight(input, ".")
+	return strings.TrimRight(output, ".")
 }
 
 func parseRecordId(id string) [4]string {

aws/resource_aws_route53_record_test.go

@@ -52,6 +52,24 @@ func TestExpandRecordName(t *testing.T) {
 	}
 }
 
+func TestNormalizeAwsAliasName(t *testing.T) {
+	cases := []struct {
+		Input, Output string
+	}{
+		{"www.nonexample.com", "www.nonexample.com"},
+		{"www.nonexample.com.", "www.nonexample.com"},
+		{"dualstack.name-123456789.region.elb.amazonaws.com", "name-123456789.region.elb.amazonaws.com"},
+		{"NAME-123456789.region.elb.amazonaws.com", "name-123456789.region.elb.amazonaws.com"},
+	}
+
+	for _, tc := range cases {
+		actual := normalizeAwsAliasName(tc.Input)
+		if actual != tc.Output {
+			t.Fatalf("input: %s\noutput: %s", tc.Input, actual)
+		}
+	}
+}
+
 func TestParseRecordId(t *testing.T) {
 	cases := []struct {
 		Input, Zone, Name, Type, Set string
@@ -280,6 +298,25 @@ func TestAccAWSRoute53Record_alias(t *testing.T) {
 	})
 }
 
+func TestAccAWSRoute53Record_aliasUppercase(t *testing.T) {
+	rs := acctest.RandString(10)
+	config := fmt.Sprintf(testAccRoute53ElbAliasRecordUppercase, rs)
+	resource.Test(t, resource.TestCase{
+		PreCheck:      func() { testAccPreCheck(t) },
+		IDRefreshName: "aws_route53_record.alias",
+		Providers:     testAccProviders,
+		CheckDestroy:  testAccCheckRoute53RecordDestroy,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: config,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckRoute53RecordExists("aws_route53_record.alias"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccAWSRoute53Record_s3_alias(t *testing.T) {
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
@@ -968,6 +1005,36 @@ resource "aws_elb" "main" {
 }
 `
 
+const testAccRoute53ElbAliasRecordUppercase = `
+resource "aws_route53_zone" "main" {
+  name = "notexample.com"
+}
+
+resource "aws_route53_record" "alias" {
+  zone_id = "${aws_route53_zone.main.zone_id}"
+  name = "www"
+  type = "A"
+
+  alias {
+  	zone_id = "${aws_elb.main.zone_id}"
+  	name = "${aws_elb.main.dns_name}"
+  	evaluate_target_health = true
+  }
+}
+
+resource "aws_elb" "main" {
+  name = "FOOBAR-TERRAFORM-ELB-%s"
+  availability_zones = ["us-west-2a"]
+
+  listener {
+    instance_port = 80
+    instance_protocol = "http"
+    lb_port = 80
+    lb_protocol = "http"
+  }
+}
+`
+
 const testAccRoute53AliasRecord = `
 resource "aws_route53_zone" "main" {
   name = "notexample.com"