The UI needs to be changed accordingly, right?
Otherwise, the user will get an unstable behaviour while reverting a
snapshot with the current upstream UI

On 20/04/2015 15:58, Crístian Deives wrote:
> The action 'revert' is currently synchronous; that means that there's no
> way for the user to run it in background and check its status
> periodically. In some cases, reverting a snapshot can take a a few
> seconds/minutes to finish, so the best option is to change it to an
> asynchronous call.
>
> Change the implementation of the action 'revert' so it returns an
> asynchronous Task.
>
> Signed-off-by: Crístian Deives <cristiandeives@gmail.com>
> ---
>   src/kimchi/control/vm/snapshots.py |  2 +-
>   src/kimchi/mockmodel.py            | 11 +++++++++++
>   src/kimchi/model/vmsnapshots.py    | 28 ++++++++++++++++++++--------
>   tests/test_model.py                |  6 ++++--
>   tests/test_rest.py                 |  9 +++++++++
>   5 files changed, 45 insertions(+), 11 deletions(-)
>
> diff --git a/src/kimchi/control/vm/snapshots.py b/src/kimchi/control/vm/snapshots.py
> index bbebc9a..4847d59 100644
> --- a/src/kimchi/control/vm/snapshots.py
> +++ b/src/kimchi/control/vm/snapshots.py
> @@ -39,7 +39,7 @@ class VMSnapshot(Resource):
>           self.ident = ident
>           self.model_args = [self.vm, self.ident]
>           self.uri_fmt = '/vms/%s/snapshots/%s'
> -        self.revert = self.generate_action_handler('revert')
> +        self.revert = self.generate_action_handler_task('revert')
>
>       @property
>       def data(self):
> diff --git a/src/kimchi/mockmodel.py b/src/kimchi/mockmodel.py
> index dcb8bc1..286f903 100644
> --- a/src/kimchi/mockmodel.py
> +++ b/src/kimchi/mockmodel.py
> @@ -431,6 +431,15 @@ class MockModel(Model):
>           MockModel._mock_snapshots[vm_name] = snapshots
>
>       def _mock_vmsnapshot_revert(self, vm_name, name):
> +        params = {'vm_name': vm_name, 'name': name}
> +        taskid = add_task(u'/vms/%s/snapshots/%s/revert' % (vm_name, name),
> +                          self._vmsnapshot_revert_task, self.objstore, params)
> +        return self.task_lookup(taskid)
> +
> +    def _vmsnapshot_revert_task(self, cb, params):
> +        vm_name = params['vm_name']
> +        name = params['name']
> +
>           snapshots = MockModel._mock_snapshots.get(vm_name, [])
>           for sn in snapshots:
>               if sn.current:
> @@ -440,6 +449,8 @@ class MockModel(Model):
>               if sn.name == name:
>                   sn.current = True
>
> +        cb('OK', True)
> +
>
>   class MockStorageVolumes(object):
>       def __init__(self):
> diff --git a/src/kimchi/model/vmsnapshots.py b/src/kimchi/model/vmsnapshots.py
> index 3a92cdc..331f532 100644
> --- a/src/kimchi/model/vmsnapshots.py
> +++ b/src/kimchi/model/vmsnapshots.py
> @@ -29,7 +29,6 @@ from kimchi.model.tasks import TaskModel
>   from kimchi.model.vms import DOM_STATE_MAP, VMModel
>   from kimchi.model.vmstorages import VMStorageModel, VMStoragesModel
>   from kimchi.utils import add_task
> -from kimchi.xmlutils.utils import xpath_get_text
>
>
>   class VMSnapshotsModel(object):
> @@ -120,6 +119,8 @@ class VMSnapshotsModel(object):
>   class VMSnapshotModel(object):
>       def __init__(self, **kargs):
>           self.conn = kargs['conn']
> +        self.objstore = kargs['objstore']
> +        self.task = TaskModel(**kargs)
>
>       def lookup(self, vm_name, name):
>           vir_snap = self.get_vmsnapshot(vm_name, name)
> @@ -153,19 +154,30 @@ class VMSnapshotModel(object):
>                                                      'err': e.message})
>
>       def revert(self, vm_name, name):
> +        vir_dom = VMModel.get_vm(vm_name, self.conn)
> +        vir_snap = self.get_vmsnapshot(vm_name, name)
> +
> +        task_params = {'name': name, 'vm_name': vm_name,
> +                       'dom': vir_dom, 'snap': vir_snap}
> +        taskid = add_task(u'/vms/%s/snapshots/%s/revert' % (vm_name, name),
> +                          self._revert_task, self.objstore, task_params)
> +        return self.task.lookup(taskid)
> +
> +    def _revert_task(self, cb, params):
> +        vir_dom = params['dom']
> +        vir_snap = params['snap']
> +
>           try:
> -            vir_dom = VMModel.get_vm(vm_name, self.conn)
> -            vir_snap = self.get_vmsnapshot(vm_name, name)
> +            cb('reverting to snapshot')
>               vir_dom.revertToSnapshot(vir_snap, 0)
> -
> -            # get vm name recorded in the snapshot and return new uri params
> -            vm_new_name = xpath_get_text(vir_snap.getXMLDesc(0),
> -                                         'domain/name')[0]
> -            return [vm_new_name, name]
>           except libvirt.libvirtError, e:
> +            name = params['name']
> +            vm_name = params['vm_name']
> +
>               raise OperationFailed('KCHSNAP0009E', {'name': name,
>                                                      'vm': vm_name,
>                                                      'err': e.message})
> +        cb('OK', True)
>
>       def get_vmsnapshot(self, vm_name, name):
>           vir_dom = VMModel.get_vm(vm_name, self.conn)
> diff --git a/tests/test_model.py b/tests/test_model.py
> index c25929f..b53822a 100644
> --- a/tests/test_model.py
> +++ b/tests/test_model.py
> @@ -198,8 +198,10 @@ class ModelTests(unittest.TestCase):
>               snap = inst.vmsnapshot_lookup(u'kimchi-vm-new', params['name'])
>
>               # snapshot revert to the first created vm
> -            result = inst.vmsnapshot_revert(u'kimchi-vm-new', params['name'])
> -            self.assertEquals(result, [u'kimchi-vm', snap['name']])
> +            task = inst.vmsnapshot_revert(u'kimchi-vm-new', params['name'])
> +            inst.task_wait(task['id'])
> +            task = inst.task_lookup(task['id'])
> +            self.assertEquals('finished', task['status'])
>
>               vm = inst.vm_lookup(u'kimchi-vm')
>               self.assertEquals(vm['state'], snap['state'])
> diff --git a/tests/test_rest.py b/tests/test_rest.py
> index c1b81e8..3b592d6 100644
> --- a/tests/test_rest.py
> +++ b/tests/test_rest.py
> @@ -382,6 +382,15 @@ class RestTests(unittest.TestCase):
>           # Revert to snapshot
>           resp = self.request('/vms/test-vm/snapshots/%s/revert' %
>                               params['name'], '{}', 'POST')
> +        self.assertEquals(202, resp.status)
> +        task = json.loads(resp.read())
> +        wait_task(self._task_lookup, task['id'])
> +        resp = self.request('/tasks/%s' % task['id'], '{}', 'GET')
> +        task = json.loads(resp.read())
> +        self.assertEquals('finished', task['status'])
> +
> +        resp = self.request('/vms/test-vm/snapshots/%s' % params['name'],
> +                            '{}', 'GET')
>           self.assertEquals(200, resp.status)
>           snap = json.loads(resp.read())
>           resp = self.request('/vms/test-vm', '{}', 'GET')