DirectMappingError shows incorrect message when insecure_debug set to true

[yangweiwei]

When I set the rule below:
[
{
    "local": [
        {
            "user":{
                   "name":"{0}"
                   }
        },
        {
            "group": {
                   "id":"c59d9770089b4d5aaa893973bbcfb538"
                    }
        }
    ],
    "remote":[
              {
              "type":"openstack_user",
              "any_one_of": [
                        "bob"
                           ]
              }
             ]
}
]

and I want to get the unscoped token and set the 'insecure_debug' to 'True', the error shows bellow:
keystoneauth1.exceptions.http.InternalServerError: An unexpected error prevented the server from fulfilling your request: . (Disable insecure_debug mode to suppress these details.) (HTTP 500) (Request-ID: req-eb26c090-87b2-4fa8-90d9-004928a61711)

I have digging the error happens in '_update_local_mapping' method in keystone/federation/utils.py.
Some logs bellow:

2017-06-02 09:48:02.160 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] {u'remote': [{u'type': u'openstack_user', u'any_one_of': [u'bob']}], u'local': [{u'user': {u'name': u'{0}'}}, {u'group': {u'id': u'c59d9770089b4d5aaa893973bbcfb538'}}]} process /usr/lib/python2.7/site-packages/keystone/federation/utils.py:531
2017-06-02 09:48:02.160 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] _verify_all_requirements /usr/lib/python2.7/site-packages/keystone/federation/utils.py:796
2017-06-02 09:48:02.161 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] _verify_all_requirements /usr/lib/python2.7/site-packages/keystone/federation/utils.py:806
2017-06-02 09:48:02.161 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] <keystone.federation.utils.DirectMaps object at 0x7f4073fa3f90> process /usr/lib/python2.7/site-packages/keystone/federation/utils.py:537
2017-06-02 09:48:02.161 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] direct_maps: <keystone.federation.utils.DirectMaps object at 0x7f4073fa3f90> _update_local_mapping /usr/lib/python2.7/site-packages/keystone/federation/utils.py:717
2017-06-02 09:48:02.162 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] local: {u'user': {u'name': u'{0}'}} _update_local_mapping /usr/lib/python2.7/site-packages/keystone/federation/utils.py:718
2017-06-02 09:48:02.162 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] direct_maps: <keystone.federation.utils.DirectMaps object at 0x7f4073fa3f90> _update_local_mapping /usr/lib/python2.7/site-packages/keystone/federation/utils.py:717
2017-06-02 09:48:02.162 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] local: {u'name': u'{0}'} _update_local_mapping /usr/lib/python2.7/site-packages/keystone/federation/utils.py:718
2017-06-02 09:48:02.163 2933 DEBUG keystone.federation.utils [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -]
{0} _update_local_mapping /usr/lib/python2.7/site-packages/keystone/federation/utils.py:728
2017-06-02 09:48:02.169 2933 WARNING oslo_config.cfg [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] Option "rpc_backend" from group "DEFAULT" is deprecated for removal. Its value may be silently ignored in the future.
2017-06-02 09:48:02.191 2933 DEBUG keystone.auth.plugins.mapped [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] An unexpected error prevented the server from fulfilling your request. handle_unscoped_token /usr/lib/python2.7/site-packages/keystone/auth/plugins/mapped.py:283
2017-06-02 09:48:02.192 2933 WARNING keystone.common.wsgi [req-94ec1d2f-4e3e-4174-a1d7-1ff574169f1f - - - - -] An unexpected error prevented the server from fulfilling your request.

But as the design, if we set the 'insecure_debug' to True, we could see the detail error details and specifics about how the mapping failed.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/470094

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/470094
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=78eb44266cfc3e5053b71c27df7b7030641dbf53
Submitter: Jenkins
Branch: master

commit 78eb44266cfc3e5053b71c27df7b7030641dbf53
Author: yangweiwei <email address hidden>
Date: Fri Jun 2 09:53:10 2017 +0800

    Update DirectMappingError in keystone.exception

    When the correct IndexError happens in federation mapping rule, '{0}'
    is in a local section, but the value in direct_maps is null.

    Now I have set insecure_debug to 'True', and it shows like '...
    (e.g. {0} in a local section).'. But it still shows 'An unexpected...'.

    Change-Id: If6263229b153828ffa07ee3ad6004f3db7cdfd98
    Closes-Bug: #1695131

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/keystone 12.0.0.0b2 development milestone.