provider/aws: Add reader_endpoint RDS Clusters (supersedes #8878) (#8884)

* provider/aws: Add support for Aurora ReaderEndpoint

* provider/aws: Add reader_endpoint to the schema, document, test

builtin/providers/aws/resource_aws_rds_cluster.go

@@ -85,6 +85,11 @@ func resourceAwsRDSCluster() *schema.Resource {
 				Computed: true,
 			},
 
+			"reader_endpoint": &schema.Schema{
+				Type:     schema.TypeString,
+				Computed: true,
+			},
+
 			"engine": &schema.Schema{
 				Type:     schema.TypeString,
 				Computed: true,
@@ -443,6 +448,7 @@ func resourceAwsRDSClusterRead(d *schema.ResourceData, meta interface{}) error {
 	d.Set("preferred_backup_window", dbc.PreferredBackupWindow)
 	d.Set("preferred_maintenance_window", dbc.PreferredMaintenanceWindow)
 	d.Set("kms_key_id", dbc.KmsKeyId)
+	d.Set("reader_endpoint", dbc.ReaderEndpoint)
 
 	var vpcg []string
 	for _, g := range dbc.VpcSecurityGroups {

builtin/providers/aws/resource_aws_rds_cluster_test.go

@@ -30,6 +30,8 @@ func TestAccAWSRDSCluster_basic(t *testing.T) {
 						"aws_rds_cluster.default", "storage_encrypted", "false"),
 					resource.TestCheckResourceAttr(
 						"aws_rds_cluster.default", "db_cluster_parameter_group_name", "default.aurora5.6"),
+					resource.TestCheckResourceAttrSet(
+						"aws_rds_cluster.default", "reader_endpoint"),
 				),
 			},
 		},

website/source/docs/providers/aws/r/rds_cluster.html.markdown

@@ -94,6 +94,8 @@ The following attributes are exported:
 * `preferred_backup_window` - The backup window
 * `preferred_maintenance_window` - The maintenance window
 * `endpoint` - The DNS address of the RDS instance
+* `reader_endpoint` - A read-only endpoint for the Aurora cluster, automatically
+load-balanced across replicas
 * `engine` - The database engine
 * `engine_version` - The database engine version
 * `maintenance_window` - The instance maintenance window