Open Stack

Tl;dr oslo.config wasn't logging warnings about deprecated config
options, do we need to support them for another cycle?

A set of patches to remove deprecated options in Nova was landed on
Thursday[1], these were marked as deprecated during the juno dev cycle
and got removed now that kilo has started.

Most of the deprecated config options are listed as deprecated in the
documentation for nova.conf changes[2] linked to from the Nova upgrade
section in the Juno release notes[3] (the deprecated cinder config
options are not listed here along with the allowed_direct_url_schemes
glance option).

My main worry is that there were no warnings about these options being
deprecated in nova's logs (as a result they were still being used in
tripleo), once I noticed tripleo's CI jobs were failing and discovered
the reason I submitted 4 reverts to put back the deprecated options in
nova[4] as I believe they should now be supported for another cycle
(along with a fix to oslo.config to log warnings about their use). The 4
patches have now been blocked as they go "against our deprecation policy".

I believe the correct way to handle this is to support these options for
another cycle so that other operators don't get hit when upgrading to
kilo. While at that same time fix oslo.config to report the deprecated
options in kilo.

I have marked this mail with the [all] tag because there are other
projects using the same "deprecated_name" (or "deprecated_group")
parameter when adding config options, I think those projects also now
need to support their deprecated options for another cycle.

I've also opened a bug for this against tripleo, nova and oslo.conf[5]
and for the moment in tripleo-ci I have pinned the version of nova we
use to something from before the commits were merged while we get a
chance to correctly use the new name for each of the options that were
deprecated.

On a side node, When trying to look up the deprecation policy I wasn't
able to find it so if anybody has a link handy can you point me at it.

Thanks,
Derek

[1] https://review.openstack.org/#/c/132900/
    https://review.openstack.org/#/c/132887/
    https://review.openstack.org/#/c/132885/
    https://review.openstack.org/#/c/132901/
[2]
http://docs.openstack.org/trunk/config-reference/content/nova-conf-changes-master.html
[3] https://wiki.openstack.org/wiki/ReleaseNotes/Juno#Upgrade_Notes_2
[4]
https://review.openstack.org/#/q/status:open+project:openstack/nova+branch:master+topic:redeprecate,n,z
[5] https://bugs.launchpad.net/tripleo/+bug/1390427