keystone spamming logs with stacktraces for non critical errors

[Rudolf Vriend]

Several api's dump errors with full stack traces into the logs, although it usually is perfectly OK that someone issues a api-request for an object that does not exist.

This log spam makes it hard to filter between real issues and simple 'record not found' situations..

Some examples:
https://github.com/openstack/keystone/blob/master/keystone/auth/controllers.py#L193
https://github.com/openstack/keystone/blob/master/keystone/auth/controllers.py#L457
https://github.com/openstack/keystone/blob/master/keystone/auth/plugins/core.py#L150
https://github.com/openstack/keystone/blob/master/keystone/auth/plugins/core.py#L180

Suggest to use LOG.error with some meaningful error message instead.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/333490

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/334742

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/334742
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=ba1a07f2c386ec1db55933ea25b244aa230661e5
Submitter: Jenkins
Branch: master

commit ba1a07f2c386ec1db55933ea25b244aa230661e5
Author: Steve Martinelli <email address hidden>
Date: Mon Jun 27 22:59:34 2016 -0400

    Do not spam the log with uncritical stacktraces

    This change reduces the amount of stacktrace spam in the
    keystone logs due to authentication attempts with identifiers
    that point to non-existent objects (users, domains, projects).

    Closes-Bug #1595513
    Co-Authored-By: Rudolf Vriend <email address hidden>

    Change-Id: I4a8e572fe31ecda45de2e80425e22714fdd4403a

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/333490
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=e4989793ab1fadeeb6797bc21023cefa91d00926
Submitter: Jenkins
Branch: master

commit e4989793ab1fadeeb6797bc21023cefa91d00926
Author: Rudolf Vriend <email address hidden>
Date: Thu Jun 23 18:51:58 2016 +0200

    Additional logging when authenticating

    Log some authentication issues that were not logged
    before, but are still useful to be aware of when
    diagnosing authentication issues.

    Related-Bug #1595513

    Change-Id: Ifca425eadba21cc8d4ff6f6e5c2376af6a1ddbe5