[Error 500] GET prices/usd when rabbitmq is down

Describe the bug Some 500 error are appearing in the logs when GET price/usd happen in the moment that rabbitmq is not responding for unknown reason.

To Reproduce Steps to reproduce the behavior:

1. Clean readis cache and turn off rabbitmq container
2. Then GET some token /prices/usd
3. Inmediatly we get a 500 error

Expected behavior I think that should catch the exception and don’t delay the task to get the price and return the current price without 500 error. Exception traceback

2022-08-03 13:42:50,833 [ERROR] [MainProcess] Internal Server Error: /api/v1/tokens/0x0AaE289A554cB3C97b3121db837eD9ce8635367F/prices/usd/
Traceback (most recent call last):  File "/usr/local/lib/python3.10/site-packages/kombu/utils/functional.py", line 30, in __call__    return self.__value__AttributeError: 'ChannelPromise' object has no attribute '__value__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 446, in _reraise_as_library_errors    yield  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 433, in _ensure_connection    return retry_over_time(  File "/usr/local/lib/python3.10/site-packages/kombu/utils/functional.py", line 312, in retry_over_time    return fun(*args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 877, in _connection_factory    self._connection = self._establish_connection()  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 812, in _establish_connection    conn = self.transport.establish_connection()  File "/usr/local/lib/python3.10/site-packages/kombu/transport/pyamqp.py", line 201, in establish_connection    conn.connect()  File "/usr/local/lib/python3.10/site-packages/amqp/connection.py", line 323, in connect    self.transport.connect()  File "/usr/local/lib/python3.10/site-packages/amqp/transport.py", line 129, in connect    self._connect(self.host, self.port, self.connect_timeout)  File "/usr/local/lib/python3.10/site-packages/amqp/transport.py", line 184, in _connect    self.sock.connect(sa)  File "/usr/local/lib/python3.10/site-packages/gevent/_socketcommon.py", line 607, in connect    raise _SocketError(err, strerror(err))ConnectionRefusedError: [Errno 111] Connection refused

The above exception was the direct cause of the following exception:

Traceback (most recent call last):  File "/usr/local/lib/python3.10/site-packages/django/core/handlers/exception.py", line 55, in inner    response = get_response(request)  File "/usr/local/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response    response = wrapped_callback(request, *callback_args, **callback_kwargs)  File "/usr/local/lib/python3.10/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view    return view_func(*args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/django/views/generic/base.py", line 84, in view    return self.dispatch(request, *args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/rest_framework/views.py", line 509, in dispatch    response = self.handle_exception(exc)  File "/usr/local/lib/python3.10/site-packages/rest_framework/views.py", line 469, in handle_exception    self.raise_uncaught_exception(exc)  File "/usr/local/lib/python3.10/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception    raise exc  File "/usr/local/lib/python3.10/site-packages/rest_framework/views.py", line 506, in dispatch    response = handler(request, *args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/django/utils/decorators.py", line 46, in _wrapper    return bound_method(*args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/django/utils/decorators.py", line 133, in _wrapped_view    response = view_func(request, *args, **kwargs)  File "/app/safe_transaction_service/tokens/views.py", line 92, in get    fiat_price_with_timestamp = next(  File "/app/safe_transaction_service/tokens/services/price_service.py", line 347, in get_cached_usd_values    for token_eth_values_with_timestamp in self.get_cached_token_eth_values(  File "/app/safe_transaction_service/tokens/services/price_service.py", line 324, in get_cached_token_eth_values    task_result = calculate_token_eth_price_task.delay(  File "/usr/local/lib/python3.10/site-packages/celery/app/task.py", line 425, in delay    return self.apply_async(args, kwargs)  File "/usr/local/lib/python3.10/site-packages/celery/app/task.py", line 575, in apply_async    return app.send_task(  File "/usr/local/lib/python3.10/site-packages/celery/app/base.py", line 788, in send_task    amqp.send_task_message(P, name, message, **options)  File "/usr/local/lib/python3.10/site-packages/celery/app/amqp.py", line 510, in send_task_message    ret = producer.publish(  File "/usr/local/lib/python3.10/site-packages/kombu/messaging.py", line 177, in publish    return _publish(  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 523, in _ensured    return fun(*args, **kwargs)  File "/usr/local/lib/python3.10/site-packages/kombu/messaging.py", line 186, in _publish    channel = self.channel  File "/usr/local/lib/python3.10/site-packages/kombu/messaging.py", line 209, in _get_channel    channel = self._channel = channel()  File "/usr/local/lib/python3.10/site-packages/kombu/utils/functional.py", line 32, in __call__    value = self.__value__ = self.__contract__()  File "/usr/local/lib/python3.10/site-packages/kombu/messaging.py", line 225, in <lambda>    channel = ChannelPromise(lambda: connection.default_channel)  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 895, in default_channel    self._ensure_connection(**conn_opts)  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 432, in _ensure_connection    with ctx():  File "/usr/local/lib/python3.10/contextlib.py", line 153, in __exit__    self.gen.throw(typ, value, traceback)  File "/usr/local/lib/python3.10/site-packages/kombu/connection.py", line 450, in _reraise_as_library_errors    raise ConnectionError(str(exc)) from exckombu.exceptions.OperationalError: [Errno 111] Connection refused

[moisses89]

Could you attach the traceback for the exception?

Added

[moisses89]

Then 500 for this case is correct. Closing the issue.