Use oslo-config-generator conf to load options from libraries

... instead of importing library modules just to load options.

Change-Id: I55270b330d1fe98817df4d419e8c26c90440e3a6
(cherry picked from commit 7f35a177d3)
(cherry picked from commit 5a19c63267)
(cherry picked from commit 92e5813ef5)
(cherry picked from commit c854616cf4)

etc/oslo-config-generator/manila.conf

@@ -1,9 +1,12 @@
 [DEFAULT]
 output_file = etc/manila/manila.conf.sample
 namespace = manila
-namespace = oslo.messaging
-namespace = oslo.middleware.cors
-namespace = oslo.middleware.http_proxy_to_wsgi
+namespace = oslo.concurrency
 namespace = oslo.db
 namespace = oslo.db.concurrency
+namespace = oslo.log
+namespace = oslo.messaging
+namespace = oslo.middleware
+namespace = oslo.policy
+namespace = oslo.service.sslutils
 namespace = keystonemiddleware.auth_token

manila/opts.py

@@ -19,12 +19,6 @@ __all__ = [
 import copy
 import itertools
 
-import oslo_concurrency.opts
-import oslo_log._options
-import oslo_middleware.opts
-import oslo_policy.opts
-import oslo_service.sslutils
-
 import manila.api.common
 import manila.api.middleware.auth
 import manila.common.config
@@ -200,14 +194,9 @@ _opts = [
      list(itertools.chain(manila.network.neutron.api.neutron_opts))),
 ]
 
-_opts.extend(oslo_concurrency.opts.list_opts())
-_opts.extend(oslo_log._options.list_opts())
-_opts.extend(oslo_middleware.opts.list_opts())
-_opts.extend(oslo_policy.opts.list_opts())
 _opts.extend(manila.network.neutron.api.list_opts())
 _opts.extend(manila.compute.nova.list_opts())
 _opts.extend(manila.volume.cinder.list_opts())
-_opts.extend(oslo_service.sslutils.list_opts())
 
 
 def list_opts():