@@ -53,7 +53,12 @@ Write the local.conf file for use by devstack

    A dictionary mapping service names to boolean values.  If the

    boolean value is ``false``, a ``disable_service`` line will be

    emitted for the service name.  If it is ``true``, then

-   ``enable_service`` will be emitted.  All other values are ignored.

+   ``enable_service`` will be emitted. All other values are ignored.

+   The special key ``base`` can be used to enable or disable the base set of

+   services enabled by default. If ``base`` is found, it will processed before

+   all other keys. If its value is ``False`` a ``disable_all_services`` will be

+   emitted; if its value is ``True`` nothing will be emitted since base

+   services are enabled by default.

 .. zuul:rolevar:: devstack_plugins

    :type: dict

@@ -124,6 +124,9 @@ class LocalConf(object):

                 self.localrc.append('enable_plugin {} {}'.format(k, v))

     def handle_services(self, services):

+        base_services = services.pop('base', True)

+        if not base_services:

+            self.localrc.append('disable_all_services')

         for k, v in services.items():

             if v is False:

                 self.localrc.append('disable_service {}'.format(k))