ec2utils: introduce helper function to prepend '/dev/' in mappings

Introduce a helper function to prepend /dev/ to device name
in block device mapping of bundle

1 files changed, 10 insertions, 0 deletions

diff --git a/nova/api/ec2/ec2utils.py b/nova/api/ec2/ec2utils.py
index 9839f8604..bae1e0ee5 100644
--- a/nova/api/ec2/ec2utils.py
+++ b/nova/api/ec2/ec2utils.py
@@ -154,3 +154,13 @@ def properties_root_device_name(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:
+        virtual = m['virtual']
+        if ((virtual == 'swap' or virtual.startswith('ephemeral')) and
+            (not m['device'].startswith('/'))):
+            m['device'] = '/dev/' + m['device']
+    return mappings