central agent will throw error on startup

As discussed in IRC, this is entirely the problem with entry points being used as the basis for plugin configuration.

It's fine for setup.cfg to say where a plugin can be found, but is it right that it also says that the system should try to activate that plugin?

there technically is away to validate before loading

http://docs.openstack.org/developer/stevedore/managers.html#enabledextensionmanager

I don't see the central agent functioning normally with devstack latest code base. It fails with the following error on fedora 21.

2015-02-23 15:43:48.620 50372 CRITICAL ceilometer [-] ImportError: No module named awsauth
2015-02-23 15:43:48.620 50372 TRACE ceilometer Traceback (most recent call last):
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/usr/bin/ceilometer-agent-central", line 9, in <module>
2015-02-23 15:43:48.620 50372 TRACE ceilometer load_entry_point('ceilometer==2015.1.dev91', 'console_scripts', 'ceilometer-agent-central')()
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/cmd/polling.py", line 74, in main_central
2015-02-23 15:43:48.620 50372 TRACE ceilometer os_service.launch(manager.AgentManager(['central'])).wait()
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/agent/manager.py", line 47, in __init__
2015-02-23 15:43:48.620 50372 TRACE ceilometer group_prefix=cfg.CONF.polling.partitioning_group_prefix)
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/agent/base.py", line 223, in __init__
2015-02-23 15:43:48.620 50372 TRACE ceilometer self.extensions = list(itertools.chain(*list(extensions)))
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/agent/base.py", line 218, in <genexpr>
2015-02-23 15:43:48.620 50372 TRACE ceilometer for namespace in namespaces)
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/agent/base.py", line 250, in _extensions
2015-02-23 15:43:48.620 50372 TRACE ceilometer on_load_failure_callback=_catch_extension_load_error,
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/usr/lib/python2.7/site-packages/stevedore/extension.py", line 92, in __init__
2015-02-23 15:43:48.620 50372 TRACE ceilometer verify_requirements)
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/usr/lib/python2.7/site-packages/stevedore/extension.py", line 170, in _load_plugins
2015-02-23 15:43:48.620 50372 TRACE ceilometer self._on_load_failure_callback(self, ep, err)
2015-02-23 15:43:48.620 50372 TRACE ceilometer File "/opt/stack/ceilometer/ceilometer/agent/base.py", line 245, in _catch_extension_load_error
2015-02-23 15:43:48.620 50372 TRACE ceilometer raise exc
2015-02-23 15:43:48.620 50372 TRACE ceilometer ImportError: No module named awsauth
2015-02-23 15:43:48.620 50372 TRACE ceilometer
ceilometer-acentral failed to start

Rabi, please sync with latest code as the awsauth code was reverted https://review.openstack.org/#/c/158329/

Rabi, can you confirm whether you're still seeing this issue in master?

this is still valid... or at least it shows up on every gate. i'll check with swami to see if he's actually working on it.

Any update for this bug, I am still facing this problem:

ceilometer central service can successfully start but with the following error:

Failed to import extension for rgw.usage: No module named awsauth
......

Fix proposed to branch: master
Review: https://review.openstack.org/185295

Reviewed: https://review.openstack.org/185295
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=c9eb2d44df7cafde1294123d66445ebef4cfb76d
Submitter: Jenkins
Branch: master

commit c9eb2d44df7cafde1294123d66445ebef4cfb76d
Author: Lan Qi song <email address hidden>
Date: Mon May 25 10:35:57 2015 +0800

    Disable rgw pollster when aws module not found

    This patch will raise PollsterPermanentError in rgw pollster
    to disable those pollsters when requests-aws module not found.

    Change-Id: I880ec77467fae026f25e61d04d7dd76e08834b08
    Closes-Bug: #1424746

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/187901

Change abandoned by Lan Qi Song (<email address hidden>) on branch: stable/kilo
Review: https://review.openstack.org/187901
Reason: Thanks gordc & Zhi Qiang, abandon this patch.