Add support for creating a new volume from a existing snapshot with EC2 API.

3 files changed, 21 insertions, 4 deletions

diff --git a/nova/volume/api.py b/nova/volume/api.py
index f5285f31f..bd073964d 100644
--- a/nova/volume/api.py
+++ b/nova/volume/api.py
@@ -39,7 +39,13 @@ LOG = logging.getLogger('nova.volume')
 class API(base.Base):
     """API for interacting with the volume manager."""
 
-    def create(self, context, size, name, description):
+    def create(self, context, size, snapshot_id, name, description):
+        if snapshot_id != None:
+            snapshot = self.get_snapshot(context, snapshot_id)
+            if snapshot['status'] != "available":
+                raise exception.ApiError(_("Snapshot status must be available"))
+            size = snapshot['volume_size']
+
         if quota.allowed_volumes(context, 1, size) < 1:
             pid = context.project_id
             LOG.warn(_("Quota exceeeded for %(pid)s, tried to create"
@@ -51,6 +57,7 @@ class API(base.Base):
             'size': size,
             'user_id': context.user_id,
             'project_id': context.project_id,
+            'snapshot_id': snapshot_id,
             'availability_zone': FLAGS.storage_availability_zone,
             'status': "creating",
             'attach_status': "detached",
@@ -62,7 +69,8 @@ class API(base.Base):
                  FLAGS.scheduler_topic,
                  {"method": "create_volume",
                   "args": {"topic": FLAGS.volume_topic,
-                           "volume_id": volume['id']}})
+                           "volume_id": volume['id'],
+                           "snapshot_id": snapshot_id}})
         return volume
 
     def delete(self, context, volume_id):
diff --git a/nova/volume/driver.py b/nova/volume/driver.py
index ba0a7efef..02b0d50f4 100644
--- a/nova/volume/driver.py
+++ b/nova/volume/driver.py
@@ -101,6 +101,10 @@ class VolumeDriver(object):
                            volume['name'],
                            FLAGS.volume_group)
 
+    def create_volume_from_snapshot(self, volume, snapshot):
+        """Creates a volume from a snapshot."""
+        raise NotImplementedError()
+
     def delete_volume(self, volume):
         """Deletes a logical volume."""
         try:
diff --git a/nova/volume/manager.py b/nova/volume/manager.py
index 87fd3bf17..7d47fc191 100644
--- a/nova/volume/manager.py
+++ b/nova/volume/manager.py
@@ -90,7 +90,7 @@ class VolumeManager(manager.SchedulerDependentManager):
             else:
                 LOG.info(_("volume %s: skipping export"), volume['name'])
 
-    def create_volume(self, context, volume_id):
+    def create_volume(self, context, volume_id, snapshot_id):
         """Creates and exports the volume."""
         context = context.elevated()
         volume_ref = self.db.volume_get(context, volume_id)
@@ -108,7 +108,12 @@ class VolumeManager(manager.SchedulerDependentManager):
             vol_size = volume_ref['size']
             LOG.debug(_("volume %(vol_name)s: creating lv of"
                     " size %(vol_size)sG") % locals())
-            model_update = self.driver.create_volume(volume_ref)
+            if snapshot_id == None:
+                model_update = self.driver.create_volume(volume_ref)
+            else:
+                snapshot_ref = self.db.snapshot_get(context, snapshot_id)
+                model_update = self.driver.create_volume_from_snapshot(volume_ref,
+                                                                       snapshot_ref)
             if model_update:
                 self.db.volume_update(context, volume_ref['id'], model_update)