ec2utils: factor generic helper function into generic place

This patch moves out a helper function, properties_root_device_name(),
into generic file nova/block_device.py.

5 files changed, 45 insertions, 24 deletions

diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index 16ca1ed2a..b25f74f61 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -30,6 +30,7 @@ import tempfile
 import time
 import shutil
 
+from nova import block_device
 from nova import compute
 from nova import context
 
@@ -1240,7 +1241,7 @@ class CloudController(object):
         i['architecture'] = image['properties'].get('architecture')
 
         properties = image['properties']
-        root_device_name = ec2utils.properties_root_device_name(properties)
+        root_device_name = block_device.properties_root_device_name(properties)
         root_device_type = 'instance-store'
         for bdm in properties.get('block_device_mapping', []):
             if (bdm.get('device_name') == root_device_name and
@@ -1313,7 +1314,7 @@ class CloudController(object):
 
         def _root_device_name_attribute(image, result):
             result['rootDeviceName'] = \
-                    ec2utils.properties_root_device_name(image['properties'])
+                block_device.properties_root_device_name(image['properties'])
             if result['rootDeviceName'] is None:
                 result['rootDeviceName'] = _DEFAULT_ROOT_DEVICE_NAME
 
diff --git a/nova/api/ec2/ec2utils.py b/nova/api/ec2/ec2utils.py
index bae1e0ee5..14891debb 100644
--- a/nova/api/ec2/ec2utils.py
+++ b/nova/api/ec2/ec2utils.py
@@ -137,25 +137,6 @@ def dict_from_dotted_str(items):
     return args
 
 
-def properties_root_device_name(properties):
-    """get root device name from image meta data.
-    If it isn't specified, return None.
-    """
-    root_device_name = None
-
-    # NOTE(yamahata): see image_service.s3.s3create()
-    for bdm in properties.get('mappings', []):
-        if bdm['virtual'] == 'root':
-            root_device_name = bdm['device']
-
-    # NOTE(yamahata): register_image's command line can override
-    #                 <machine>.manifest.xml
-    if 'root_device_name' in properties:
-        root_device_name = properties['root_device_name']
-
-    return root_device_name
-
-
 def mappings_prepend_dev(mappings):
     """Prepend '/dev/' to 'device' entry of swap/ephemeral virtual type"""
     for m in mappings:
diff --git a/nova/block_device.py b/nova/block_device.py
new file mode 100644
index 000000000..963dffa37
--- /dev/null
+++ b/nova/block_device.py
@@ -0,0 +1,35 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 Isaku Yamahata <yamahata@valinux co jp>
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+def properties_root_device_name(properties):
+    """get root device name from image meta data.
+    If it isn't specified, return None.
+    """
+    root_device_name = None
+
+    # NOTE(yamahata): see image_service.s3.s3create()
+    for bdm in properties.get('mappings', []):
+        if bdm['virtual'] == 'root':
+            root_device_name = bdm['device']
+
+    # NOTE(yamahata): register_image's command line can override
+    #                 <machine>.manifest.xml
+    if 'root_device_name' in properties:
+        root_device_name = properties['root_device_name']
+
+    return root_device_name
diff --git a/nova/compute/api.py b/nova/compute/api.py
index 9994e5724..43a95aa17 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -22,6 +22,7 @@ import eventlet
 import re
 import time
 
+from nova import block_device
 from nova import db
 from nova import exception
 from nova import flags
@@ -218,7 +219,7 @@ class API(base.Base):
         if reservation_id is None:
             reservation_id = utils.generate_uid('r')
 
-        root_device_name = ec2utils.properties_root_device_name(
+        root_device_name = block_device.properties_root_device_name(
             image['properties'])
 
         base_options = {
diff --git a/nova/tests/test_api.py b/nova/tests/test_api.py
index 26ac5ff24..d5f653bc6 100644
--- a/nova/tests/test_api.py
+++ b/nova/tests/test_api.py
@@ -27,6 +27,7 @@ import random
 import StringIO
 import webob
 
+from nova import block_device
 from nova import context
 from nova import exception
 from nova import test
@@ -147,10 +148,12 @@ class Ec2utilsTestCase(test.TestCase):
         properties0 = {'mappings': mappings}
         properties1 = {'root_device_name': '/dev/sdb', 'mappings': mappings}
 
-        root_device_name = ec2utils.properties_root_device_name(properties0)
+        root_device_name = block_device.properties_root_device_name(
+            properties0)
         self.assertEqual(root_device_name, '/dev/sda1')
 
-        root_device_name = ec2utils.properties_root_device_name(properties1)
+        root_device_name = block_device.properties_root_device_name(
+            properties1)
         self.assertEqual(root_device_name, '/dev/sdb')
 
     def test_mapping_prepend_dev(self):