Commit 9ef83cbc by Dudás Ádám

vm: base class for operations

parent 3d50c288
from __future__ import absolute_import, unicode_literals
from common.models import activity_context
from ..tasks.local_tasks import async_operation
from .activity import InstanceActivity
class Operation:
"""Base class for VM operations.
acl_level = 'owner'
async_queue = ''
def __init__(self, instance):
"""Initialize a new operation bound to the specified VM instance.
self.instance = instance
def __call__(self, **kwargs):
"""Execute the operation synchronously.
activity = self.__prelude(kwargs)
return self._exec_op(activity=activity, **kwargs)
def __unicode__(self):
def __prelude(self, kwargs):
"""This method contains the shared prelude of __call__ and async.
user = kwargs.setdefault('user', None)
self.check_auth(user) # TODO what's check_auth's specification?
return self.create_activity(user=user)
def _exec_op(self, activity, user=None, **kwargs):
"""Execute the operation inside the specified activity's context.
with activity_context(activity, on_abort=self.on_abort,
return self._operation(activity, user, **kwargs)
def _operation(self, activity, user=None, **kwargs):
"""This method is the operation's particular implementation.
Deriving classes should implement this method.
def async(self, **kwargs):
"""Execute the operation asynchronously.
Only a quick, preliminary check is ran before queuing the job.
activity = self.__prelude(kwargs)
return async_operation.apply_async(args=(,,, kwargs=kwargs,
def check_precond(self):
def check_auth(self, user):
def create_activity(self, user=None):
return InstanceActivity.create(code_suffix=self.activity_code_suffix,
instance=self.instance, user=user)
def on_abort(self, activity, error):
"""This method is called when the operation aborts (i.e. raises an
def on_commit(self, activity):
"""This method is called when the operation executes successfully.
from manager.mancelery import celery
def async_operation(operation_id, instance_pk, activity_pk, **kwargs):
from vm.models import Instance, InstanceActivity
instance = Instance.objects.get(pk=instance_pk)
operation = getattr(instance, operation_id)
activity = InstanceActivity.objects.get(pk=activity_pk)
# save async task UUID to activity
activity.task_uuid =
return operation._exec_op(activity=activity, **kwargs)
# TODO: Keep synchronised with Instance funcs
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