烧瓶投掷'Working outside of request context.'

Question

我正在尝试将芹菜用于烧瓶中的应用，但我会遇到以下错误"在请求上下文之外工作"。听起来我正在尝试在前端提出请求之前访问请求对象，但是我无法弄清楚什么问题。我很感激您是否可以让我知道有什么问题。

[2017-04-26 13:33:04,940: INFO/MainProcess] Received task: app.result[139a2679-e9df-49b9-ab42-1f53a09c01fd]  
[2017-04-26 13:33:06,168: ERROR/PoolWorker-2] Task app.result[139a2679-e9df-49b9-ab42-1f53a09c01fd] raised unexpected: RuntimeError('Working outside of request context.nnThis typically means that you attempted to use functionality that needednan active HTTP request.  Consult the documentation on testing forninformation about how to avoid this problem.',)
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/celery/app/trace.py", line 367, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/Users/Pooneh/projects/applications/ray_tracer_app_flask/flask_celery.py", line 14, in __call__
    return TaskBase.__call__(self, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/celery/app/trace.py", line 622, in __protected_call__
    return self.run(*args, **kwargs)
  File "/Users/Pooneh/projects/applications/ray_tracer_app_flask/app.py", line 33, in final_result
    light_position = request.args.get("light_position", "(0, 0, 0)", type=str)
  File "/Library/Python/2.7/site-packages/werkzeug/local.py", line 343, in __getattr__
    return getattr(self._get_current_object(), name)
  File "/Library/Python/2.7/site-packages/werkzeug/local.py", line 302, in _get_current_object
    return self.__local()
  File "/Library/Python/2.7/site-packages/flask/globals.py", line 37, in _lookup_req_object
    raise RuntimeError(_request_ctx_err_msg)
RuntimeError: Working outside of request context.
This typically means that you attempted to use functionality that needed
an active HTTP request.  Consult the documentation on testing for
information about how to avoid this problem.

app.py

app = Flask(__name__)
app.config.update(CELERY_BROKER_URL = 'amqp://localhost//',
CELERY_RESULT_BACKEND='amqp://localhost//')
celery = make_celery(app)

@app.route('/')
def my_form():
    return render_template("form.html")
@app.route('/result')
def result():
    final_result.delay()
    return "celery!"
@celery.task(name='app.result')
def final_result():
    light_position = request.args.get("light_position", "(0, 0, 0)", type=str)
    light_position_coor = re.findall("[-+]?d*.d+|[-+]?d+", light_position)
    x = float(light_position_coor[0])
    y = float(light_position_coor[1])
    z = float(light_position_coor[2])
    encoded = base64.b64encode(open("/Users/payande/projects/applications/app_flask/static/pic.png", "rb").read())
    return jsonify(data=encoded)

Answer 1

芹菜任务由http请求之外的背景工人运行(这是使用它们的主要好处之一(，因此您无法在任务中访问request对象。<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

您可以将数据传递给任务作为参数：

final_result.delay(request.args.get("light_position"))
@celery.task(name='app.result')
def final_result(light_position):
    ...

当然，这也意味着该任务的返回值不能在HTTP响应中使用(因为在发送响应后可以完成任务(。