Merge pull request #16885 from hashicorp/b-final-snapshot-identifier-validation

resource/db_instance: include check for first char in final_snapshot_identifier ValidationFunc

Author: anGie44

aws/resource_aws_db_instance.go

@@ -263,20 +263,12 @@ func resourceAwsDbInstance() *schema.Resource {
 			"final_snapshot_identifier": {
 				Type:     schema.TypeString,
 				Optional: true,
-				ValidateFunc: func(v interface{}, k string) (ws []string, es []error) {
-					value := v.(string)
-					if !regexp.MustCompile(`^[0-9A-Za-z-]+$`).MatchString(value) {
-						es = append(es, fmt.Errorf(
-							"only alphanumeric characters and hyphens allowed in %q", k))
-					}
-					if regexp.MustCompile(`--`).MatchString(value) {
-						es = append(es, fmt.Errorf("%q cannot contain two consecutive hyphens", k))
-					}
-					if regexp.MustCompile(`-$`).MatchString(value) {
-						es = append(es, fmt.Errorf("%q cannot end in a hyphen", k))
-					}
-					return
-				},
+				ValidateFunc: validation.All(
+					validation.StringMatch(regexp.MustCompile(`^[A-Za-z]`), "must begin with alphabetic character"),
+					validation.StringMatch(regexp.MustCompile(`^[0-9A-Za-z-]+$`), "must only contain alphanumeric characters and hyphens"),
+					validation.StringDoesNotMatch(regexp.MustCompile(`--`), "cannot contain two consecutive hyphens"),
+					validation.StringDoesNotMatch(regexp.MustCompile(`-$`), "cannot end in a hyphen"),
+				),
 			},
 
 			"restore_to_point_in_time": {

aws/resource_aws_db_instance_test.go

@@ -442,7 +442,7 @@ func TestAccAWSDBInstance_FinalSnapshotIdentifier(t *testing.T) {
 		PreCheck:  func() { testAccPreCheck(t) },
 		Providers: testAccProviders,
 		// testAccCheckAWSDBInstanceSnapshot verifies a database snapshot is
-		// created, and subequently deletes it
+		// created, and subsequently deletes it
 		CheckDestroy: testAccCheckAWSDBInstanceSnapshot,
 		Steps: []resource.TestStep{
 			{

website/docs/r/db_instance.html.markdown

@@ -120,7 +120,7 @@ For supported values, see the EngineVersion parameter in [API action CreateDBIns
 Note that for Amazon Aurora instances the engine version must match the [DB cluster](/docs/providers/aws/r/rds_cluster.html)'s engine version'.
 * `final_snapshot_identifier` - (Optional) The name of your final DB snapshot
 when this DB instance is deleted. Must be provided if `skip_final_snapshot` is
-set to `false`.
+set to `false`. The value must begin with a letter, only contain alphanumeric characters and hyphens, and not end with a hyphen or contain two consecutive hyphens. Must not be provided when deleting a read replica.
 * `iam_database_authentication_enabled` - (Optional) Specifies whether or
 mappings of AWS Identity and Access Management (IAM) accounts to database
 accounts is enabled.