Cannot enable uploading images with URL for Newton+ using IMAGES_ALLOW_LOCATION=True

[Nobuto Murata]

Image uploading with URL (URL to the image) was enabled by default before. But since Newton it's behind a config flag. There is no way to re-enable uploading with URL with the charm for Newton or newer releases.

[doc/source/configuration/settings.rst]

IMAGES_ALLOW_LOCATION
~~~~~~~~~~~~~~~~~~~~~

.. versionadded:: 10.0.0(Newton)

Default: ``False``

If set to ``True``, this setting allows users to specify an image location
(URL) as the image source when creating or updating images. Depending on
the Glance version, the ability to set an image location is controlled by
policies and/or the Glance configuration. Therefore IMAGES_ALLOW_LOCATION
should only be set to ``True`` if Glance is configured to allow specifying a
location. This setting has no effect when the Keystone catalog doesn't contain
a Glance v2 endpoint.

[Corey Bryant (corey.bryant)]

Thanks Nobuto.

For some history, IMAGES_ALLOW_LOCATION was introduced upstream in the following commit when support was added for glance v2: http://paste.ubuntu.com/25489609/

And here's the upstream code in particular that does the checking of IMAGES_ALLOW_LOCATION and corresponding policy: http://paste.ubuntu.com/25489603/

Prior to introduction of that commit upstream, it appears that image upload from URL was allowed by default.

It seems like we should add a config option to (re)enable this functionality.

[Corey Bryant (corey.bryant)]

I'm marking this as a bug vs wishlist since the (upstream) default changed on a release boundary there's no way to enable this functionality via the charm.

[Nobuto Murata (nobuto)]

@Corey,

After searching a bit, it might be ok with a wishlist rather than a bug. Because IMAGES_ALLOW_LOCATION seems brought by a sane reason as glance v1 vs v2 does not have 1:1 feature mapping.

The request to support IMAGES_ALLOW_LOCATION was a originally from a customer, but here is an excerpt of my answer.

====

After looking up, it's not so simple. Horizon had a major overhaul when switching from Glance API v1 to v2 in Newton. "Copy from URL" feature in v1 was not implemented in v2, so Horizon cannot copy images from URL. Also, Glance API v1 is deprecated and will be removed sooner or later.

https://blueprints.launchpad.net/horizon/+spec/horizon-glance-v2

    When using v2:

    Same as v1, except:
    - Metadata menu available for images in the admin panel
    - Possibly it won't be possible to upload an image via URL (until bug 1419040 is resolved)

Glance API v2 has a simpler function called "Import from URL"(https://wiki.openstack.org/wiki/Glance-tasks-import), but Horizon as an upstream does not support it yet.

[Corey Bryant (corey.bryant)]

Thanks for the info Nobuto. Let's mark this as wishlist then.

[Boris Lukashev (rageltman)]

How is this a wishlist item? Its a basic function of OpenStack to give Horizon an image URL so that the stack uses its fast links to the WAN for acquisition, instead of your slow WFH link to download then upload it it.
When things like this are not exposed in juju, users have to edit their configs by hand, breaking support, and making the customer decide between usability and paying canonical for support. Seems like a bad call, commercially.