

**Description**

We are using a 3rd party executor which has the ability to use multiple queues, however the `default_queue` is defined under the `celery` heading and is used regardless of the executor that you are using.

See: https://github.com/apache/airflow/blob/2.0.1/airflow/models/baseoperator.py#L366

It would be nice to decouple the default_queue configuration argument away from the celery section to allow other executors to utilise this functionality with less confusion.

**Are you willing to submit a PR?**

Yep! Will open a pull request shortly


**Related Issues**

Not that I'm aware of.

airflow/config_templates/default_celery.py
'ssl_certfile': conf.get('celery', 'SSL_CERT'),
                'ssl_ca_certs': conf.get('celery', 'SSL_CACERT'),
                'ssl_cert_reqs': ssl.CERT_REQUIRED,
            }
        else:
            raise AirflowException(
                'The broker you configured does not support SSL_ACTIVE to be True. '
                'Please use RabbitMQ or Redis if you would like to use SSL for broker.'
            )
        DEFAULT_CELERY_CONFIG['broker_use_ssl'] = broker_use_ssl
except AirflowConfigException:
    raise AirflowException(
        'AirflowConfigException: SSL_ACTIVE is True, '
        'please ensure SSL_KEY, '
        'SSL_CERT and SSL_CACERT are set'
    )
except Exception as e:
    raise AirflowException(
        'Exception: There was an unknown Celery SSL Error. '
        'Please ensure you want to use '
        'SSL and/or have all necessary certs and key ({}).'.format(e)
    )
result_backend = DEFAULT_CELERY_CONFIG['result_backend']
if 'amqp://' in result_backend or 'redis://' in result_backend or 'rpc://' in result_backend:
    log.warning(
        "You have configured a result_backend of %s, it is highly recommended "
        "to use an alternative result_backend (i.e. a database).",
        result_backend,
    )