[LIBCLOUD-672] [LIBCLOUD-673] Create volume from snapshot on EC2 and OS

CHANGES.rst

@@ -7,6 +7,12 @@ Changes with Apache Libcloud in development
 Compute
 ~~~~~~~
 
+- Add support for creating volumes based on snapshots to EC2 and OS drivers.
+  Also modify signature of base NodeDriver.create_volume to reflect the fact
+  that all drivers expect a StorageSnapshot object as the snapshot argument.
+  (GITHUB-467, LIBCLOUD-672)
+  [Allard Hoeve]
+
 - Improve GCE create_node, make sure ex_get_disktype function
   (GITHUB-448)
   [Markos Gogoulos]

docs/upgrade_notes.rst

@@ -5,6 +5,16 @@ This page describes how to upgrade from a previous version to a new version
 which contains backward incompatible or semi-incompatible changes and how to
 preserve the old behavior when this is possible.
 
+Development
+-----------
+
+* The base signature of NodeDriver.create_volume has changed. The snapshot
+  argument is now expected to be a VolumeSnapshot instead of a string.
+  The older signature was never correct for built-in drivers, but custom
+  drivers may break. (GCE accepted strings, names or None and still does.
+  Other drivers did not implement creating volumes from snapshots at all 
+  until now.)
+
 Libcloud 0.16.0
 ---------------
 

libcloud/compute/base.py

@@ -997,9 +997,9 @@ def create_volume(self, size, name, location=None, snapshot=None):
                                (optional)
         :type location: :class:`.NodeLocation`
 
-        :param snapshot:  Name of snapshot from which to create the new
-                               volume.  (optional)
-        :type snapshot:  ``str``
+        :param snapshot:  Snapshot from which to create the new
+                          volume.  (optional)
+        :type snapshot: :class:`.VolumeSnapshot`
 
         :return: The newly created volume.
         :rtype: :class:`StorageVolume`

libcloud/compute/drivers/ec2.py

@@ -2314,6 +2314,23 @@ def destroy_node(self, node):
     def create_volume(self, size, name, location=None, snapshot=None,
                       ex_volume_type='standard', ex_iops=None):
         """
+        Create a new volume.
+
+        :param size: Size of volume in gigabytes (required)
+        :type size: ``int``
+
+        :param name: Name of the volume to be created
+        :type name: ``str``
+
+        :param location: Which data center to create a volume in. If
+                               empty, undefined behavior will be selected.
+                               (optional)
+        :type location: :class:`.NodeLocation`
+
+        :param snapshot:  Snapshot from which to create the new
+                               volume.  (optional)
+        :type snapshot:  :class:`.VolumeSnapshot`
+
         :param location: Datacenter in which to create a volume in.
         :type location: :class:`.ExEC2AvailabilityZone`
 
@@ -2324,6 +2341,9 @@ def create_volume(self, size, name, location=None, snapshot=None,
                      that the volume supports. Only used if ex_volume_type
                      is io1.
         :type iops: ``int``
+
+        :return: The newly created volume.
+        :rtype: :class:`StorageVolume`
         """
         valid_volume_types = ['standard', 'io1', 'gp2']
 
@@ -2335,6 +2355,9 @@ def create_volume(self, size, name, location=None, snapshot=None,
             raise ValueError('Invalid volume type specified: %s' %
                              (ex_volume_type))
 
+        if snapshot:
+            params['SnapshotId'] = snapshot.id
+
         if location is not None:
             params['AvailabilityZone'] = location.availability_zone.name
 

libcloud/compute/drivers/openstack.py

@@ -149,23 +149,44 @@ def list_nodes(self, ex_all_tenants=False):
             self.connection.request('/servers/detail', params=params).object)
 
     def create_volume(self, size, name, location=None, snapshot=None):
+        """
+        Create a new volume.
+
+        :param size: Size of volume in gigabytes (required)
+        :type size: ``int``
+
+        :param name: Name of the volume to be created
+        :type name: ``str``
+
+        :param location: Which data center to create a volume in. If
+                               empty, undefined behavior will be selected.
+                               (optional)
+        :type location: :class:`.NodeLocation`
+
+        :param snapshot:  Snapshot from which to create the new
+                          volume.  (optional)
+        :type snapshot:  :class:`.VolumeSnapshot`
+
+        :return: The newly created volume.
+        :rtype: :class:`StorageVolume`
+        """
+        volume = {
+            'display_name': name,
+            'display_description': name,
+            'size': size,
+            'volume_type': None,
+            'metadata': {
+                'contents': name,
+            },
+            'availability_zone': location
+        }
+
         if snapshot:
-            raise NotImplementedError(
-                "create_volume does not yet support create from snapshot")
+            volume['snapshot_id'] = snapshot.id
+
         resp = self.connection.request('/os-volumes',
                                        method='POST',
-                                       data={
-                                           'volume': {
-                                               'display_name': name,
-                                               'display_description': name,
-                                               'size': size,
-                                               'volume_type': None,
-                                               'metadata': {
-                                                   'contents': name,
-                                               },
-                                               'availability_zone': location,
-                                           }
-                                       })
+                                       data={'volume': volume})
         return self._to_volume(resp.object)
 
     def destroy_volume(self, volume):