AmqpServiceWrapper.py

class AmqpServiceWrapper(object):
    '''
    A wrapper class that takes care of the business of initialization:
        - Creates an RpcChannel with the given parameters
        - Instantiates a protobuf service of the given class
        - Delegats further attribute access to the Service instance.
        
    '''
    class ParameterMissing(Exception):
        pass
        
    def __init__(self, 
        pb_service_class=None,
        amqp_channel=None,
        exchange='Control_Exchange',
        request_routing_key=None,
        reply_queue=None,
        timeout_ms=5000,
        max_retries=3):
        
        self.amqp_channel = ampq_channel or MessageBus().channel
        self.exchange = exchange
        
        # Required parameters:
        for param in ('pb_service_class', 'reply_queue', 'request_routing_key'):
            if locals()[param]:
                setattr(self, param, locals(param))
            else:
                raise ParameterMissing("%s is a required parameter." % param)
                
        self.rpc_channel = RpcChannel(self.CONTROL_EXCHANGE_NAME, self.REPLY_QUEUE_NAME, 'dispatch', max_retries=3, timeout_ms=timeout_ms)
        self.rpc_service = service_stub_class(self.rpc_channel)
        #self.amqp_rpc_controller = AmqpRpcController()
   
    # Delegate other attribute access to protobuf rpc_service instance
    def __getattr__(self, name):
        return object.__getattribute__(self.rpc_service, name)