data-source/aws_kms_alias: Prevent crash on aliases without target key

aws/data_source_aws_kms_alias.go

@@ -64,20 +64,24 @@ func dataSourceAwsKmsAliasRead(d *schema.ResourceData, meta interface{}) error {
 	d.SetId(time.Now().UTC().String())
 	d.Set("arn", alias.AliasArn)
 
-	aliasARN, err := arn.Parse(*alias.AliasArn)
-	if err != nil {
-		return err
-	}
-	targetKeyARN := arn.ARN{
-		Partition: aliasARN.Partition,
-		Service:   aliasARN.Service,
-		Region:    aliasARN.Region,
-		AccountID: aliasARN.AccountID,
-		Resource:  fmt.Sprintf("key/%s", *alias.TargetKeyId),
-	}
-	d.Set("target_key_arn", targetKeyARN.String())
+	// AWS service aliases do not return TargetKeyId:
+	// https://docs.aws.amazon.com/kms/latest/APIReference/API_ListAliases.html
+	if alias.TargetKeyId != nil {
+		aliasARN, err := arn.Parse(*alias.AliasArn)
+		if err != nil {
+			return err
+		}
+		targetKeyARN := arn.ARN{
+			Partition: aliasARN.Partition,
+			Service:   aliasARN.Service,
+			Region:    aliasARN.Region,
+			AccountID: aliasARN.AccountID,
+			Resource:  fmt.Sprintf("key/%s", *alias.TargetKeyId),
+		}
+		d.Set("target_key_arn", targetKeyARN.String())
 
-	d.Set("target_key_id", alias.TargetKeyId)
+		d.Set("target_key_id", alias.TargetKeyId)
+	}
 
 	return nil
 }

aws/data_source_aws_kms_alias_test.go

@@ -2,6 +2,7 @@ package aws
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -10,32 +11,69 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
-func TestAccDataSourceAwsKmsAlias(t *testing.T) {
+func TestAccDataSourceAwsKmsAlias_AwsService(t *testing.T) {
+	name := "alias/aws/redshift"
+	resourceName := "data.aws_kms_alias.test"
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:  func() { testAccPreCheck(t) },
+		Providers: testAccProviders,
+		Steps: []resource.TestStep{
+			resource.TestStep{
+				Config: testAccDataSourceAwsKmsAlias_name(name),
+				Check: resource.ComposeTestCheckFunc(
+					testAccDataSourceAwsKmsAliasCheckExists(resourceName),
+					resource.TestMatchResourceAttr(resourceName, "arn", regexp.MustCompile(fmt.Sprintf("^arn:[^:]+:kms:[^:]+:[^:]+:%s$", name))),
+					resource.TestCheckResourceAttr(resourceName, "name", name),
+					resource.TestCheckNoResourceAttr(resourceName, "target_key_arn"),
+					resource.TestCheckNoResourceAttr(resourceName, "target_key_id"),
+				),
+			},
+		},
+	})
+}
+
+func TestAccDataSourceAwsKmsAlias_CMK(t *testing.T) {
 	rInt := acctest.RandInt()
+	aliasResourceName := "aws_kms_alias.test"
+	datasourceAliasResourceName := "data.aws_kms_alias.test"
+
 	resource.Test(t, resource.TestCase{
 		PreCheck:  func() { testAccPreCheck(t) },
 		Providers: testAccProviders,
 		Steps: []resource.TestStep{
 			resource.TestStep{
-				Config: testAccDataSourceAwsKmsAlias(rInt),
+				Config: testAccDataSourceAwsKmsAlias_CMK(rInt),
 				Check: resource.ComposeTestCheckFunc(
-					testAccDataSourceAwsKmsAliasCheck("data.aws_kms_alias.by_name"),
+					testAccDataSourceAwsKmsAliasCheckExists(datasourceAliasResourceName),
+					testAccDataSourceAwsKmsAliasCheckCMKAttributes(aliasResourceName, datasourceAliasResourceName),
 				),
 			},
 		},
 	})
 }
 
-func testAccDataSourceAwsKmsAliasCheck(name string) resource.TestCheckFunc {
+func testAccDataSourceAwsKmsAliasCheckExists(name string) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
-		rs, ok := s.RootModule().Resources[name]
+		_, ok := s.RootModule().Resources[name]
 		if !ok {
 			return fmt.Errorf("root module has no resource called %s", name)
 		}
 
-		kmsKeyRs, ok := s.RootModule().Resources["aws_kms_alias.single"]
+		return nil
+	}
+}
+
+func testAccDataSourceAwsKmsAliasCheckCMKAttributes(aliasResourceName, datasourceAliasResourceName string) resource.TestCheckFunc {
+	return func(s *terraform.State) error {
+		rs, ok := s.RootModule().Resources[datasourceAliasResourceName]
+		if !ok {
+			return fmt.Errorf("root module has no resource called %s", datasourceAliasResourceName)
+		}
+
+		kmsKeyRs, ok := s.RootModule().Resources[aliasResourceName]
 		if !ok {
-			return fmt.Errorf("can't find aws_kms_alias.single in state")
+			return fmt.Errorf("can't find %s in state", aliasResourceName)
 		}
 
 		attr := rs.Primary.Attributes
@@ -69,19 +107,25 @@ func testAccDataSourceAwsKmsAliasCheck(name string) resource.TestCheckFunc {
 	}
 }
 
-func testAccDataSourceAwsKmsAlias(rInt int) string {
+func testAccDataSourceAwsKmsAlias_name(name string) string {
+	return fmt.Sprintf(`
+data "aws_kms_alias" "test" {
+  name = "%s"
+}`, name)
+}
+
+func testAccDataSourceAwsKmsAlias_CMK(rInt int) string {
 	return fmt.Sprintf(`
-resource "aws_kms_key" "one" {
+resource "aws_kms_key" "test" {
     description = "Terraform acc test"
     deletion_window_in_days = 7
 }
 
-resource "aws_kms_alias" "single" {
+resource "aws_kms_alias" "test" {
     name = "alias/tf-acc-key-alias-%d"
-    target_key_id = "${aws_kms_key.one.key_id}"
+    target_key_id = "${aws_kms_key.test.key_id}"
 }
 
-data "aws_kms_alias" "by_name" {
-  name = "${aws_kms_alias.single.name}"
-}`, rInt)
+%s
+`, rInt, testAccDataSourceAwsKmsAlias_name("${aws_kms_alias.test.name}"))
 }