Use the Connection.baremetal adapter for ironicclient Session

The result of get_session does not respect baremetal-specific options
like baremetal_endpoint_override in clouds.yaml.

Change-Id: Idccf4a0fc055dc9b81705b9e3b632a61a8891cfa

metalsmith/_provisioner.py

@@ -62,8 +62,10 @@ class Provisioner(object):
             raise TypeError('Either session or cloud_region must be provided, '
                             'but not both')
         else:
-            session = cloud_region.get_session()
             self.connection = connection.Connection(config=cloud_region)
+            # NOTE(dtantsur): Connection.baremetal is a keystoneauth Adapter
+            # for baremetal API.
+            session = self.connection.baremetal
 
         self._api = _os_api.API(session, self.connection)
         self._dry_run = dry_run

metalsmith/test/test_provisioner.py

@@ -50,6 +50,8 @@ class TestInit(testtools.TestCase):
     @mock.patch.object(_provisioner.connection, 'Connection', autospec=True)
     def test_cloud_region_only(self, mock_conn):
         region = mock.Mock()
+        mock_conn.return_value.baremetal = mock.Mock(spec=['get_endpoint'])
+        mock_conn.return_value.baremetal.get_endpoint.return_value = 'http://'
         _provisioner.Provisioner(cloud_region=region)
         mock_conn.assert_called_once_with(config=region)