Apparently a new validation has been added to the service API which requires a specific name for the domain for the DbSystem

Author: rohanbhattacharjee

provider/database_db_system_resource_test.go

@@ -69,7 +69,7 @@ func (s *ResourceDatabaseDBSystemTestSuite) TestAccResourceDatabaseDBSystem() {
 					cpu_core_count = "2"
 					ssh_public_keys = ["ssh-rsa KKKLK3NzaC1yc2EAAAADAQABAAABAQC+UC9MFNA55NIVtKPIBCNw7++ACXhD0hx+Zyj25JfHykjz/QU3Q5FAU3DxDbVXyubgXfb/GJnrKRY8O4QDdvnZZRvQFFEOaApThAmCAM5MuFUIHdFvlqP+0W+ZQnmtDhwVe2NCfcmOrMuaPEgOKO3DOW6I/qOOdO691Xe2S9NgT9HhN0ZfFtEODVgvYulgXuCCXsJs+NUqcHAOxxFUmwkbPvYi0P0e2DT8JKeiOOC8VKUEgvVx+GKmqasm+Y6zHFW7vv3g2GstE1aRs3mttHRoC/JPM86PRyIxeWXEMzyG5wHqUu4XZpDbnWNxi6ugxnAGiL3CrIFdCgRNgHz5qS1l MustWin"]
 					display_name = "-tf-db-system"
-					domain = "mycompany.com"
+					domain = "${oci_core_subnet.t.dns_label}.${oci_core_virtual_network.t.dns_label}.oraclevcn.com"
 					hostname = "myOracleDB"
 					data_storage_size_in_gb = "256"
 					license_model = "LICENSE_INCLUDED"