keystone-manage token_flush fails unexpectedly

[Lance Bragstad]

The UUID token provider and SQL token storage driver were removed when Rocky opened for development [0]. The keystone-manage token_flush command was not removed with the rest of the code. As a result, if you run keystone-manage token_flush, you'll get an unexpected error:

> keystone-manage token_flush
CRITICAL keystone [-] Unhandled error: AttributeError: 'module' object has no attribute 'persistence'
ERROR keystone Traceback (most recent call last):
ERROR keystone File "/usr/local/bin/keystone-manage", line 10, in <module>
ERROR keystone sys.exit(main())
ERROR keystone File "/opt/stack/keystone/keystone/cmd/manage.py", line 45, in main
ERROR keystone cli.main(argv=sys.argv, config_files=config_files)
ERROR keystone File "/opt/stack/keystone/keystone/cmd/cli.py", line 1412, in main
ERROR keystone CONF.command.cmd_class.main()
ERROR keystone File "/opt/stack/keystone/keystone/cmd/cli.py", line 889, in main
ERROR keystone token_manager = token.persistence.PersistenceManager()
ERROR keystone AttributeError: 'module' object has no attribute 'persistence'
ERROR keystone

Even though we've advertised the removal of UUID and SQL token storage for a long time, and people shouldn't be relying on this anymore, we should either fix this or remove the token_flush command.

[0] https://review.openstack.org/#/c/543060/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/556889

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/556889
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=9ca374091b795d77fe3fba45599e5ad13aed5c51
Submitter: Zuul
Branch: master

commit 9ca374091b795d77fe3fba45599e5ad13aed5c51
Author: Lance Bragstad <email address hidden>
Date: Tue Mar 27 15:18:50 2018 +0000

    Log warning when using token_flush

    The `keystone-manage token_flush` command was useful when we
    supported token format that were actually written to disk. Now that
    keystone has moved towards formats that don't require physical
    storage in the name of scalability, we no longer need the
    token_flush utility.

    This commit logs a warning when using `keystone-manage token_flush`
    so that people are aware they don't need to use it anymore if they
    are using supported upstream non-persistent token providers.

    Change-Id: I14d1e8a3ae367c8f13b6819a1a216f3f8f6b001a
    Closes-Bug: 1759289

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/keystone 14.0.0.0b1 development milestone.