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()
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 _remote_workflow(ctx, func, args, kwargs):
def update_execution_cancelled():
update_execution_status(ctx.execution_id, Execution.CANCELLED)
_send_workflow_cancelled_event(ctx)
rest = get_rest_client()
parent_queue, child_queue = (Queue.Queue(), Queue.Queue())
try:
if rest.executions.get(ctx.execution_id).status in \
(Execution.CANCELLING, Execution.FORCE_CANCELLING):
# execution has been requested to be cancelled before it
# was even started
update_execution_cancelled()
return api.EXECUTION_CANCELLED_RESULT
update_execution_status(ctx.execution_id, Execution.STARTED)
_send_workflow_started_event(ctx)
# the actual execution of the workflow will run in another
# thread - this wrapper is the entry point for that
# thread, and takes care of forwarding the result or error
# back to the parent thread
def child_wrapper():
try:
ctx.internal.start_event_monitor()
workflow_result = _execute_workflow_function(
ctx, func, args, kwargs)
child_queue.put({'result': workflow_result})
except api.ExecutionCancelled:
child_queue.put({
'result': api.EXECUTION_CANCELLED_RESULT})
except BaseException as workflow_ex:
tb = StringIO()
traceback.print_exc(file=tb)
err = {
'type': type(workflow_ex).__name__,
'message': str(workflow_ex),
'traceback': tb.getvalue()
}
child_queue.put({'error': err})
finally:
ctx.internal.stop_event_monitor()
api.queue = parent_queue
# starting workflow execution on child thread
t = Thread(target=child_wrapper)
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
has_sent_cancelling_action = False
result = None
execution = None
while True:
# check if child thread sent a message
try:
data = child_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(ctx.execution_id)
if execution.status == Execution.FORCE_CANCELLING:
result = api.EXECUTION_CANCELLED_RESULT
break
elif not has_sent_cancelling_action and \
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 process or possibly
# 'force-cancelling' requests
parent_queue.put({'action': 'cancel'})
has_sent_cancelling_action = True
# updating execution status and sending events according to
# how the execution ended
if result == api.EXECUTION_CANCELLED_RESULT:
update_execution_cancelled()
if execution and execution.status == Execution.FORCE_CANCELLING:
# TODO: kill worker externally
raise RequestSystemExit()
else:
update_execution_status(ctx.execution_id, Execution.TERMINATED)
_send_workflow_succeeded_event(ctx)
return result
except RequestSystemExit:
raise
except BaseException as e:
if isinstance(e, exceptions.ProcessExecutionError):
error_traceback = e.traceback
else:
error = StringIO()
traceback.print_exc(file=error)
error_traceback = error.getvalue()
update_execution_status(ctx.execution_id, Execution.FAILED,
error_traceback)
_send_workflow_failed_event(ctx, e, error_traceback)
raise