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

6 files changed, 81 insertions, 6 deletions

diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index 6daf299b9..5d4d2ad27 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -639,11 +639,19 @@ class CloudController(object):
         v['display_description'] = volume['display_description']
         return v
 
-    def create_volume(self, context, size, **kwargs):
-        LOG.audit(_("Create volume of %s GB"), size, context=context)
+    def create_volume(self, context, **kwargs):
+        size = kwargs.get('size');
+        if kwargs.get('snapshot_id') != None:
+            snapshot_id = ec2utils.ec2_id_to_id(kwargs['snapshot_id'])
+            LOG.audit(_("Create volume from snapshot %s"), snapshot_id, context=context)
+        else:
+            snapshot_id = None
+            LOG.audit(_("Create volume of %s GB"), size, context=context)
+            
         volume = self.volume_api.create(
                 context,
                 size=size,
+                snapshot_id=snapshot_id,
                 name=kwargs.get('display_name'),
                 description=kwargs.get('display_description'))
         # TODO(vish): Instance should be None at db layer instead of
diff --git a/nova/db/sqlalchemy/migrate_repo/versions/016_add_snapshot_id_to_volumes.py b/nova/db/sqlalchemy/migrate_repo/versions/016_add_snapshot_id_to_volumes.py
new file mode 100644
index 000000000..0a50123bf
--- /dev/null
+++ b/nova/db/sqlalchemy/migrate_repo/versions/016_add_snapshot_id_to_volumes.py
@@ -0,0 +1,48 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 MORITA Kazutaka.
+# 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.
+
+from sqlalchemy import *
+from migrate import *
+
+from nova import log as logging
+
+
+meta = MetaData()
+
+
+# Table stub-definitions
+# Just for the ForeignKey and column creation to succeed, these are not the
+# actual definitions of instances or services.
+#
+volumes = Table('volumes', meta,
+                Column('id', Integer(), primary_key=True, nullable=False),
+                )
+
+#
+# New Column
+#
+
+snapshot_id = Column('snapshot_id', Integer())
+
+
+def upgrade(migrate_engine):
+    # Upgrade operations go here. Don't create your own engine;
+    # bind migrate_engine to your metadata
+    meta.bind = migrate_engine
+
+    # Add columns to existing tables
+    volumes.create_column(snapshot_id)
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 9abe4d9ae..afc2ea4e4 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -287,6 +287,8 @@ class Volume(BASE, NovaBase):
     user_id = Column(String(255))
     project_id = Column(String(255))
 
+    snapshot_id = Column(String(255))
+
     host = Column(String(255))  # , ForeignKey('hosts.id'))
     size = Column(Integer)
     availability_zone = Column(String(255))  # TODO(vish): foreign key?
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)