Make 'noop' the explicit default of default_storage_interface

Currently it's implicit in the driver_factory code. This change makes
it more visible and removes the special case from driver_factory.

Change-Id: I1502ab22171110d48dee29827e0fda9171a74931

ironic/common/driver_factory.py

@@ -131,15 +131,9 @@ def default_interface(hw_type, interface_type,
     :raises: NoValidDefaultForInterface if no default interface can be found.
     """
     factory = _INTERFACE_LOADERS[interface_type]
-    # Explicit interface defaults
-    additional_defaults = {
-        'storage': 'noop'
-    }
 
     # The fallback default from the configuration
     impl_name = getattr(CONF, 'default_%s_interface' % interface_type)
-    if impl_name is None:
-        impl_name = additional_defaults.get(interface_type)
 
     if impl_name is not None:
         # Check that the default is correct for this type

ironic/conf/default.py

@@ -151,6 +151,7 @@ driver_opts = [
                 default=['cinder', 'noop'],
                 help=_ENABLED_IFACE_HELP.format('storage')),
     cfg.StrOpt('default_storage_interface',
+               default='noop',
                help=_DEFAULT_IFACE_HELP.format('storage')),
     cfg.ListOpt('enabled_vendor_interfaces',
                 default=['ipmitool', 'no-vendor'],

ironic/tests/base.py

@@ -131,6 +131,8 @@ class TestCase(oslo_test_base.BaseTestCase):
         self.config(enabled_hardware_types=['fake-hardware',
                                             'manual-management'])
         for iface in drivers_base.ALL_INTERFACES:
+            default = None
+
             # Restore some reasonable defaults
             if iface == 'network':
                 values = ['flat', 'noop', 'neutron']
@@ -142,12 +144,13 @@ class TestCase(oslo_test_base.BaseTestCase):
             elif iface == 'boot':
                 values.append('pxe')
             elif iface == 'storage':
+                default = 'noop'
                 values.append('noop')
             elif iface not in {'network', 'power', 'management'}:
                 values.append('no-%s' % iface)
 
             self.config(**{'enabled_%s_interfaces' % iface: values,
-                           'default_%s_interface' % iface: None})
+                           'default_%s_interface' % iface: default})
         self.set_defaults(host='fake-mini',
                           debug=True)
         self.set_defaults(connection="sqlite://",