Fix CI tests- declare consumer queue exclusive, pin docker images

CHANGELOG.md

@@ -11,6 +11,15 @@ headers that will be sent with every request from a connection. This setting
 accepts a mapping of header names to `connection.header.Header` objects which
 can retrieve values from get params, cookies etc.
 
+### Fixed
+- The message consumer queue is now declared `exclusive` instead of
+`auto_delete`. RabbitMQ 4 refuses to declare a transient non-exclusive queue,
+which stopped the consumer before it bound to the exchange, so no triggered
+messages were delivered. The queue is private to a single consumer, so
+`exclusive` is the correct declaration and also works on RabbitMQ 3. The test
+suite pins RabbitMQ 3.13, matching the version our projects run, but the
+consumer now works on both 3 and 4.
+
 ## [2.5.0] - 2019-10-02
 ### Added
 - `Hub` objects now have the method `on_ping` that allows you to hook custom

docker-compose.yml

@@ -1,8 +1,6 @@
-version: '3.6'
-
 services:
   rabbitmq:
-    image: rabbitmq:management
+    image: rabbitmq:3.13-management
     ports:
       - ${RABBIT_MQ_PORT:-5672}:5672
       - ${RABBIT_MQ_ADMIN_PORT:-15672}:15672
@@ -31,7 +29,7 @@ services:
       - 8080:8080
 
   nginx:
-    image: nginx
+    image: nginx:1.31
     volumes:
       - ./docker/nginx/nginx.conf:/etc/nginx/nginx.conf
     ports:

high_templar/rabbitmq.py

@@ -40,8 +40,11 @@ async def run(app):
 
                 app.logger.debug("create queue {}".format(QUEUE_NAME))
 
+                # Exclusive rather than plain auto_delete: the queue is private
+                # to this consumer (its name carries a per-process uuid), and
+                # RabbitMQ 4 refuses to declare a transient non-exclusive queue.
                 queue = await channel.declare_queue(
-                    QUEUE_NAME, auto_delete=True, durable=False
+                    QUEUE_NAME, exclusive=True, durable=False
                 )
                 await queue.bind(exchange=config['exchange_name'], routing_key='*')