root / snf-cyclades-app / synnefo / logic / amqp_connection.py @ 3c755209
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# Copyright 2011 GRNET S.A. All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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#
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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# SUCH DAMAGE.
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#
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# The views and conclusions contained in the software and documentation are
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# those of the authors and should not be interpreted as representing official
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# policies, either expressed or implied, of GRNET S.A.
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import time |
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import socket |
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from logging import getLogger |
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from amqplib import client_0_8 as amqp |
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from django.conf import settings |
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log = getLogger('synnefo.logic')
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_conn = None
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_chan = None
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def _connect(): |
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global _conn, _chan
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# Force the _conn object to re-initialize
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_conn = None
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retry = 0
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while _conn == None: |
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try:
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_conn = amqp.Connection(host=settings.RABBIT_HOST, |
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userid=settings.RABBIT_USERNAME, |
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password=settings.RABBIT_PASSWORD, |
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virtual_host=settings.RABBIT_VHOST) |
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except socket.error:
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retry += 1
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if retry < 5 : |
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log.exception("Cannot establish connection to AMQP. Retrying...")
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time.sleep(1)
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else:
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raise AMQPError("Queue error") |
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_chan = _conn.channel() |
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def send(payload, exchange, key): |
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"""
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Send payload to the specified exchange using the provided routing key.
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This method will try reconnecting to the message server if a connection
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error occurs when sending the message. All other errors are forwarded
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to the client.
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"""
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global _conn, _chan
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if payload is None: |
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raise AMQPError("Message is empty") |
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if exchange is None: |
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raise AMQPError("Unknown exchange") |
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if key is None: |
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raise AMQPError("Unknown routing key") |
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msg = amqp.Message(payload) |
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msg.properties["delivery_mode"] = 2 # Persistent |
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while True: |
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try:
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_chan.basic_publish(msg, |
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exchange=exchange, |
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routing_key=key) |
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return
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except socket.error as se: |
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log.exception("Server went away, reconnecting...")
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_connect() |
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except Exception as e: |
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if _conn is None: |
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_connect() |
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else:
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log.exception('Caught unexpected exception (msg: %s)', msg)
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raise AMQPError("Error sending message to exchange %s with \ |
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key %s.Payload: %s. Error was: %s",
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(exchange, key, payload, e.message)) |
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def __init__(): |
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_connect() |
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class AMQPError(Exception): |
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pass
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