Allow charm to specify endpoint to use for glance/keystone/radosgw - internal/admin/public

[Diko Parvanov]

The charm currently uses the admin endpoint for auth_host and public for service_host - add option to specify which endpoint to use from the catalog.

[Alex Kavanagh (ajkavanagh)]

Triaged as wishlist:

Setting to incomplete, because the requirement needs to be fleshed out a bit more. e.g. what would the new config value be, scope of settings, use-case for usage, etc. Thanks.

[Diko Parvanov (dparv)]

The new config option could be something like:
endpoint-to-use:
options: 'internal', 'admin', 'public'
default: 'public'

Use case is charm currently defaults to the public endpoint, if we want to use internal or admin for access to glance/ceph-radosgw/keystone - we need to be able to configure it.