azure/aria/aria-extension-cloudify/src/aria/aria/orchestrator/workflows/executor/celery.py

   1 # Licensed to the Apache Software Foundation (ASF) under one or more
   2 # contributor license agreements.  See the NOTICE file distributed with
   3 # this work for additional information regarding copyright ownership.
   4 # The ASF licenses this file to You under the Apache License, Version 2.0
   5 # (the "License"); you may not use this file except in compliance with
   6 # the License.  You may obtain a copy of the License at
   7 #
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 """
  17 Celery task executor.
  18 """
  19
  20 import threading
  21 import Queue
  22
  23 from aria.orchestrator.workflows.executor import BaseExecutor
  24
  25
  26 class CeleryExecutor(BaseExecutor):
  27     """
  28     Celery task executor.
  29     """
  30
  31     def __init__(self, app, *args, **kwargs):
  32         super(CeleryExecutor, self).__init__(*args, **kwargs)
  33         self._app = app
  34         self._started_signaled = False
  35         self._started_queue = Queue.Queue(maxsize=1)
  36         self._tasks = {}
  37         self._results = {}
  38         self._receiver = None
  39         self._stopped = False
  40         self._receiver_thread = threading.Thread(target=self._events_receiver)
  41         self._receiver_thread.daemon = True
  42         self._receiver_thread.start()
  43         self._started_queue.get(timeout=30)
  44
  45     def _execute(self, ctx):
  46         self._tasks[ctx.id] = ctx
  47         arguments = dict(arg.unwrapped for arg in ctx.task.arguments.itervalues())
  48         arguments['ctx'] = ctx.context
  49         self._results[ctx.id] = self._app.send_task(
  50             ctx.operation_mapping,
  51             kwargs=arguments,
  52             task_id=ctx.task.id,
  53             queue=self._get_queue(ctx))
  54
  55     def close(self):
  56         self._stopped = True
  57         if self._receiver:
  58             self._receiver.should_stop = True
  59         self._receiver_thread.join()
  60
  61     @staticmethod
  62     def _get_queue(task):
  63         return None if task else None  # TODO
  64
  65     def _events_receiver(self):
  66         with self._app.connection() as connection:
  67             self._receiver = self._app.events.Receiver(connection, handlers={
  68                 'task-started': self._celery_task_started,
  69                 'task-succeeded': self._celery_task_succeeded,
  70                 'task-failed': self._celery_task_failed,
  71             })
  72             for _ in self._receiver.itercapture(limit=None, timeout=None, wakeup=True):
  73                 if not self._started_signaled:
  74                     self._started_queue.put(True)
  75                     self._started_signaled = True
  76                 if self._stopped:
  77                     return
  78
  79     def _celery_task_started(self, event):
  80         self._task_started(self._tasks[event['uuid']])
  81
  82     def _celery_task_succeeded(self, event):
  83         task, _ = self._remove_task(event['uuid'])
  84         self._task_succeeded(task)
  85
  86     def _celery_task_failed(self, event):
  87         task, async_result = self._remove_task(event['uuid'])
  88         try:
  89             exception = async_result.result
  90         except BaseException as e:
  91             exception = RuntimeError(
  92                 'Could not de-serialize exception of task {0} --> {1}: {2}'
  93                 .format(task.name, type(e).__name__, str(e)))
  94         self._task_failed(task, exception=exception)
  95
  96     def _remove_task(self, task_id):
  97         return self._tasks.pop(task_id), self._results.pop(task_id)