misleading documentation of filesystem_store_metadata_file config opt

[Brian Rosmaita]

In glance:

The short discussion of the filesystem_store_metadata_file option in doc/source/admin/manage-images.rst is misleading on two counts:

(1) It makes it sound like the location metadata is dynamically pulled from the file and returned in the image-show response for any image. In fact, the way this works is that glance will use the info in the file when it writes the image location--so you will only see this metadata for images created *after* the option has been set.

(2) The example is misleading in that it uses the same UUID for the mountpoint and for the image_id, which I suppose would work, but it makes it look like the two fields are related.

See discussion about this in the glance channel log: http://eavesdrop.openstack.org/irclogs/%23openstack-glance/%23openstack-glance.2018-06-01.log.html#t2018-06-01T20:26:28 to about 21:05

In glance_store:

The help text for this option is a bit vague; could stand a rewrite based on the improvements made in the glance docs.

See https://github.com/openstack/glance_store/blob/cc97b949033f892d6675692cbc8a24df3ce0e15e/glance_store/_drivers/filesystem.py#L109-L125

[Brian Rosmaita (brian-rosmaita)]

This was removed from the glance docs in train by Change-Id: I65952f70f0216d227ca14d1098d264208913e4e5
probably because it depends on show_multiple_locations. Check with Abhishek about whether it's worth correcting in the stable branches.

The option is still available in glance_store, so that part of the bug is still valid.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/724335
Committed: https://git.openstack.org/cgit/openstack/glance_store/commit/?id=65ccf371c76fc0e2a7cb26c6bae479552a77caac
Submitter: Zuul
Branch: master

commit 65ccf371c76fc0e2a7cb26c6bae479552a77caac
Author: khashf <email address hidden>
Date: Wed Apr 29 06:56:58 2020 -0700

    Clarify the filesystem_store_metadata_file config option

    The filesystem_store_metadata_file config option only applies to the new
    images created after this option is set, not existing images.

    Related conversation:
    http://eavesdrop.openstack.org/irclogs/%23openstack-glance/%23openstack-glance.2018-06-01.log.html#t2018-06-01T20:26:28

    Co-authored-by: Brian Rosmaita <email address hidden>

    Change-Id: I98503067e9dec782c73ea182c5d29d1e50073544
    Closes-bug: #1775736