def _handle_remote_workflow(self):
tenant = self.ctx._context['tenant'].get('original_name',
self.ctx.tenant_name)
rest = get_rest_client(tenant=tenant)
execution = rest.executions.get(self.ctx.execution_id,
_include=['status'])
if execution.status == Execution.STARTED:
self.ctx.resume = True
try:
amqp_client_utils.init_events_publisher()
try:
self._workflow_started()
except InvalidExecutionUpdateStatus:
self._workflow_cancelled()
return api.EXECUTION_CANCELLED_RESULT
queue = Queue.Queue()
t = AMQPWrappedThread(target=self._remote_workflow_child_thread,
args=(queue, ),
name='Workflow-Child')
t.start()
# while the child thread is executing the workflow, the parent
# thread is polling for 'cancel' requests while also waiting for
# messages from the child thread
result = None
while True:
# check if child thread sent a message
try:
data = queue.get(timeout=5)
if 'result' in data:
# child thread has terminated
result = data['result']
break
else:
# error occurred in child thread
error = data['error']
raise exceptions.ProcessExecutionError(
error['message'], error['type'],
error['traceback'])
except Queue.Empty:
pass
# A very hacky way to solve an edge case when trying to poll
# for the execution status while the DB is downgraded during
# a snapshot restore
if self.cloudify_context['workflow_id'] == 'restore_snapshot':
continue
# check for 'cancel' requests
execution = rest.executions.get(self.ctx.execution_id,
_include=['status'])
if execution.status in [
Execution.CANCELLING, Execution.FORCE_CANCELLING,
Execution.KILL_CANCELLING
]:
# send a 'cancel' message to the child thread. It is up to
# the workflow implementation to check for this message
# and act accordingly (by stopping and raising an
# api.ExecutionCancelled error, or by returning the
# deprecated api.EXECUTION_CANCELLED_RESULT as result).
# parent thread then goes back to polling for messages from
# child thread or possibly 'force-cancelling' requests
api.cancel_request = True
if execution.status == Execution.KILL_CANCELLING:
# if a custom workflow function must attempt some cleanup,
# it might attempt to catch SIGTERM, and confirm using this
# flag that it is being kill-cancelled
api.kill_request = True
if execution.status in [
Execution.FORCE_CANCELLING, Execution.KILL_CANCELLING
]:
# force-cancel additionally stops this loop immediately
result = api.EXECUTION_CANCELLED_RESULT
break
if result == api.EXECUTION_CANCELLED_RESULT:
self._workflow_cancelled()
else:
self._workflow_succeeded()
return result
except exceptions.ProcessExecutionError as e:
self._workflow_failed(e, e.traceback)
raise
except BaseException as e:
self._workflow_failed(e, traceback.format_exc())
raise
finally:
amqp_client_utils.close_amqp_client()
def _handle_remote_workflow(self):
rest = get_rest_client()
amqp_client_utils.init_amqp_client()
try:
execution = rest.executions.get(self.ctx.execution_id,
_include=['status'])
if execution.status in (Execution.CANCELLING,
Execution.FORCE_CANCELLING):
# execution has been requested to be cancelled before it was
# even started
self._workflow_cancelled()
return api.EXECUTION_CANCELLED_RESULT
self._workflow_started()
queue = Queue.Queue()
t = AMQPWrappedThread(target=self._remote_workflow_child_thread,
args=(queue,))
t.start()
# while the child thread is executing the workflow, the parent
# thread is polling for 'cancel' requests while also waiting for
# messages from the child thread
result = None
while True:
# check if child thread sent a message
try:
data = queue.get(timeout=5)
if 'result' in data:
# child thread has terminated
result = data['result']
break
else:
# error occurred in child thread
error = data['error']
raise exceptions.ProcessExecutionError(
error['message'],
error['type'],
error['traceback'])
except Queue.Empty:
pass
# check for 'cancel' requests
execution = rest.executions.get(self.ctx.execution_id,
_include=['status'])
if execution.status == Execution.FORCE_CANCELLING:
result = api.EXECUTION_CANCELLED_RESULT
break
elif execution.status == Execution.CANCELLING:
# send a 'cancel' message to the child thread. It is up to
# the workflow implementation to check for this message
# and act accordingly (by stopping and raising an
# api.ExecutionCancelled error, or by returning the
# deprecated api.EXECUTION_CANCELLED_RESULT as result).
# parent thread then goes back to polling for messages from
# child thread or possibly 'force-cancelling' requests
api.cancel_request = True
if result == api.EXECUTION_CANCELLED_RESULT:
self._workflow_cancelled()
else:
self._workflow_succeeded()
return result
except exceptions.ProcessExecutionError as e:
self._workflow_failed(e, e.traceback)
raise
except BaseException as e:
error = StringIO.StringIO()
traceback.print_exc(file=error)
self._workflow_failed(e, error.getvalue())
raise
finally:
amqp_client_utils.close_amqp_client()
