Castellan doesn't support trust-scoped token for barbican

[Vladislav Kuzmin]

When I tried to run Heat tests with `reauthentication_auth_method = trusts` some tests are failed and I can see the dollowing in nova-compute.log:

castellan.key_manager.barbican_key_manager [req-dbe35d07-d2e1-4fe9-9a80-b999665efb72 a918ad5bad3847b89ea761f4d507083f b7f3181dfc864554bd2f
bd20a4223d4e - default default] Error creating Barbican client: You are not authorized to perform the requested action: Using trust-scoped token to create another token. Create
a new trust-scoped token instead. (HTTP 403) (Request-ID: req-774770c4-7650-48db-ba78-01ffc0efc3bd): Forbidden: You are not authorized to perform the requested action: Using tru
st-scoped token to create another token. Create a new trust-scoped token instead. (HTTP 403) (Request-ID: req-774770c4-7650-48db-ba78-01ffc0efc3bd)
2019-04-15 10:05:22,438.438 6405 ERROR cursive.signature_utils [req-dbe35d07-d2e1-4fe9-9a80-b999665efb72 a918ad5bad3847b89ea761f4d507083f b7f3181dfc864554bd2fbd20a4223d4e - defa
ult default] Unable to retrieve certificate with ID b50bfd20-2757-4e19-8081-dee15d8fc56f: Key manager error: You are not authorized to perform the requested action: Using trust-
scoped token to create another token. Create a new trust-scoped token instead. (HTTP 403) (Request-ID: req-774770c4-7650-48db-ba78-01ffc0efc3bd): KeyManagerError: Key manager er
ror: You are not authorized to perform the requested action: Using trust-scoped token to create another token. Create a new trust-scoped token instead. (HTTP 403) (Request-ID: req-774770c4-7650-48db-ba78-01ffc0efc3bd)

As I can see castellan tried to create new token used trust-scope token for barbican client, but this is not allowed.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/662830
Committed: https://git.openstack.org/cgit/openstack/castellan/commit/?id=5d936763380b9d97df409de2d33b3e9b98d61a94
Submitter: Zuul
Branch: master

commit 5d936763380b9d97df409de2d33b3e9b98d61a94
Author: Vladislav Kuzmin <email address hidden>
Date: Tue Jun 4 17:09:58 2019 +0400

    Reuse existing token from RequestContext

    When castellan trying to recreate trust-scoped token
    from RequestContext keystone throw exception
    because it's not allowed.
    Starting from this commit castellan trying to
    reuse existing token constructed from RequestContext
    if get_auth_plugin() is available.

    Change-Id: I10a12b9a2a7f796eca37dd20a280d3a4015a6903
    Closes-Bug: #1827047
    Depends-On: https://review.opendev.org/#/c/664558/

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/castellan 1.4.0 release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/train
Review: https://review.opendev.org/702263

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/702263
Committed: https://git.openstack.org/cgit/openstack/castellan/commit/?id=193b4a2cc3c6b65b531b95e6b8b8b7c604ca7b77
Submitter: Zuul
Branch: stable/train

commit 193b4a2cc3c6b65b531b95e6b8b8b7c604ca7b77
Author: Vladislav Kuzmin <email address hidden>
Date: Tue Jun 4 17:09:58 2019 +0400

    Reuse existing token from RequestContext

    When castellan trying to recreate trust-scoped token
    from RequestContext keystone throw exception
    because it's not allowed.
    Starting from this commit castellan trying to
    reuse existing token constructed from RequestContext
    if get_auth_plugin() is available.

    Change-Id: I10a12b9a2a7f796eca37dd20a280d3a4015a6903
    Closes-Bug: #1827047
    Depends-On: https://review.opendev.org/#/c/664558/
    (cherry picked from commit 5d936763380b9d97df409de2d33b3e9b98d61a94)