Get rid of ambiguity in region_name

Now keystone_authtoken.region_name is used
 both for requesting admin keystone endpoint
 and default region for openstack actions.
 Default region doesn't work for environments
 with keystone in 1 region and mistrals in many
 regions.

 Due to above just specifying default_region name
 separately for openstack actions can solve the problem

Closes-Bug: #1691660

Change-Id: I1eeea298feca45de37d77d791e1548ec5e7161a1

mistral/config.py

@@ -295,7 +295,11 @@ openstack_actions_opts = [
                  'trove', 'ironic', 'designate', 'murano', 'tacker', 'senlin',
                  'aodh', 'gnocchi'],
         help=_('List of module names that support region in actions.')
-    )
+    ),
+    cfg.StrOpt(
+        'default_region',
+        help=_('Default region name for openstack actions supporting region.')
+    ),
 ]
 
 # note: this command line option is used only from sync_db and

mistral/utils/openstack/keystone.py

@@ -83,7 +83,7 @@ def get_endpoint_for_project(service_name=None, service_type=None,
     # could be passed to rest api in http header ('X-Region-Name'). Otherwise,
     # just get region from mistral configuration.
     region = (region_name or ctx.region_name or
-              CONF.keystone_authtoken.region_name)
+              CONF.openstack_actions.default_region)
 
     service_endpoints = service_catalog.get_endpoints(
         service_name=service_name,