send all tower work to a user-hidden queue

* Before, we had a special group, tower, that ran any async work that
tower needed done. This allowed users fine grain control over which
nodes did background work. However, this granularity was too complicated
for users. So now, all tower system work goes to a special non-user
exposed celery queue. Tower remains the fallback instance group to
execute jobs on. The tower group will be created upon install and
protected from deletion.

awx/settings/defaults.py

@@ -6,9 +6,9 @@ import re  # noqa
 import sys
 import ldap
 import djcelery
+import six
 from datetime import timedelta
 
-from kombu import Queue, Exchange
 from kombu.common import Broadcast
 
 # global settings
@@ -451,7 +451,7 @@ djcelery.setup_loader()
 BROKER_POOL_LIMIT = None
 BROKER_URL = 'amqp://guest:guest@localhost:5672//'
 CELERY_EVENT_QUEUE_TTL = 5
-CELERY_DEFAULT_QUEUE = 'tower'
+CELERY_DEFAULT_QUEUE = 'awx_private_queue'
 CELERY_TASK_SERIALIZER = 'json'
 CELERY_RESULT_SERIALIZER = 'json'
 CELERY_ACCEPT_CONTENT = ['json']
@@ -463,8 +463,7 @@ CELERYD_AUTOSCALER = 'awx.main.utils.autoscale:DynamicAutoScaler'
 CELERY_RESULT_BACKEND = 'djcelery.backends.database:DatabaseBackend'
 CELERY_IMPORTS = ('awx.main.scheduler.tasks',)
 CELERY_QUEUES = (
-    Queue('tower', Exchange('tower'), routing_key='tower'),
-    Broadcast('tower_broadcast_all')
+    Broadcast('tower_broadcast_all'),
 )
 CELERY_ROUTES = {}
 
@@ -515,7 +514,13 @@ AWX_INCONSISTENT_TASK_INTERVAL = 60 * 3
 # Celery queues that will always be listened to by celery workers
 # Note: Broadcast queues have unique, auto-generated names, with the alias
 # property value of the original queue name.
-AWX_CELERY_QUEUES_STATIC = ['tower_broadcast_all',]
+AWX_CELERY_QUEUES_STATIC = [
+    six.text_type(CELERY_DEFAULT_QUEUE),
+]
+
+AWX_CELERY_BCAST_QUEUES_STATIC = [
+    six.text_type('tower_broadcast_all'),
+]
 
 ASGI_AMQP = {
     'INIT_FUNC': 'awx.prepare_env',