If one tries using qpid instead of rabbitmq with heat, when heat-engine starts up it will complain that the qpid.messaging library is missing. To fix this, qpid-python should be included in requirements.txt.
2013-09-13 20:47:51.624 7031 INFO heat.engine.environment [-] Registering AWS::CloudFormation::WaitCondition -> <class 'heat.e
ngine.resources.wait_condition.WaitCondition'>
2013-09-13 20:47:51.634 7031 ERROR heat.openstack.common.threadgroup [-] Failed to import qpid.messaging
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup Traceback (most recent call last):
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup File "/opt/stack/venvs/heat/local/lib/python2.7/site-pa
ckages/heat/openstack/common/threadgroup.py", line 117, in wait
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup x.wait()
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup File "/opt/stack/venvs/heat/local/lib/python2.7/site-pa
ckages/heat/openstack/common/threadgroup.py", line 49, in wait
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup return self.thread.wait()
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup File "/opt/stack/venvs/heat/local/lib/python2.7/site-pa
ckages/eventlet/greenthread.py", line 168, in wait
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup return self._exit_event.wait()
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup File "/opt/stack/venvs/heat/local/lib/python2.7/site-pa
ckages/eventlet/event.py", line 116, in wait
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup return hubs.get_hub().switch()
2013-09-13 20:47:51.634 7031 TRACE heat.openstack.common.threadgroup File "/opt/stack/venvs/heat/local/lib/python2.7/site-pa
ckages/eventlet/hubs/hub.py", line 187, in switch
Hmm, I'm not sure we want to do this - requirements.txt reflects the requirements for the default configuration, and I don't think everyone using rabbit will really want to be forced to install qpid-python?