82 lines
2.8 KiB
ReStructuredText
82 lines
2.8 KiB
ReStructuredText
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Direct reply-to example
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==============================
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The following example demonstrates the use of the RabbitMQ "Direct reply-to" feature via `pika.BlockingConnection`. See https://www.rabbitmq.com/direct-reply-to.html for more info about this feature.
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direct_reply_to.py::
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# -*- coding: utf-8 -*-
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"""
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This example demonstrates the RabbitMQ "Direct reply-to" usage via
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`pika.BlockingConnection`. See https://www.rabbitmq.com/direct-reply-to.html
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for more info about this feature.
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"""
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import pika
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SERVER_QUEUE = 'rpc.server.queue'
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def main():
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""" Here, Client sends "Marco" to RPC Server, and RPC Server replies with
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"Polo".
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NOTE Normally, the server would be running separately from the client, but
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in this very simple example both are running in the same thread and sharing
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connection and channel.
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"""
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with pika.BlockingConnection() as conn:
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channel = conn.channel()
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# Set up server
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channel.queue_declare(queue=SERVER_QUEUE,
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exclusive=True,
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auto_delete=True)
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channel.basic_consume(on_server_rx_rpc_request, queue=SERVER_QUEUE)
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# Set up client
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# NOTE Client must create its consumer and publish RPC requests on the
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# same channel to enable the RabbitMQ broker to make the necessary
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# associations.
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#
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# Also, client must create the consumer *before* starting to publish the
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# RPC requests.
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#
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# Client must create its consumer with no_ack=True, because the reply-to
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# queue isn't real.
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channel.basic_consume(on_client_rx_reply_from_server,
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queue='amq.rabbitmq.reply-to',
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no_ack=True)
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channel.basic_publish(
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exchange='',
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routing_key=SERVER_QUEUE,
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body='Marco',
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properties=pika.BasicProperties(reply_to='amq.rabbitmq.reply-to'))
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channel.start_consuming()
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def on_server_rx_rpc_request(ch, method_frame, properties, body):
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print 'RPC Server got request:', body
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ch.basic_publish('', routing_key=properties.reply_to, body='Polo')
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ch.basic_ack(delivery_tag=method_frame.delivery_tag)
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print 'RPC Server says good bye'
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def on_client_rx_reply_from_server(ch, method_frame, properties, body):
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print 'RPC Client got reply:', body
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# NOTE A real client might want to make additional RPC requests, but in this
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# simple example we're closing the channel after getting our first reply
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# to force control to return from channel.start_consuming()
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print 'RPC Client says bye'
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ch.close()
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