Add a function for retrieving a message to an Rmq unit

zaza/openstack/charm_tests/rabbitmq_server/utils.py

@@ -380,3 +380,34 @@ def publish_amqp_message_by_unit(unit, message,
     connection.close()
 
 
+def get_amqp_message_by_unit(unit, queue="test",
+                             username="testuser1",
+                             password="changeme",
+                             ssl=False, port=None):
+    """Get an amqp message from a rmq juju unit.
+    :param unit: unit pointer
+    :param queue: message queue, default to test
+    :param username: amqp user name, default to testuser1
+    :param password: amqp user password
+    :param ssl: boolean, default to False
+    :param port: amqp port, use defaults if None
+    :returns: amqp message body as string.  Raise if get fails.
+    """
+    connection = connect_amqp_by_unit(unit, ssl=ssl,
+                                      port=port,
+                                      username=username,
+                                      password=password)
+    channel = connection.channel()
+    method_frame, _, body = channel.basic_get(queue)
+    body = body.decode()
+
+    if method_frame:
+        logging.debug('Retreived message from {} queue:\n{}'.format(queue,
+                                                                    body))
+        channel.basic_ack(method_frame.delivery_tag)
+        channel.close()
+        connection.close()
+        return body
+    else:
+        msg = 'No message retrieved.'
+        raise Exception(msg)