Comment 11 for bug 1673637

Validated xenial properly discovers configdrive when only the "latest" subdir is present:
$ name=test-proposed
$ release=xenial
$ d=$(mktemp -d)
$ wget https://git.launchpad.net/~smoser/cloud-init/+git/sru-info/plain/tools/make-configdrive-dir
make-configdrive-di 100%[===================>] 1.66K --.-KB/s in 0s
$ chmod 755 make-configdrive-dir
 lxc init $ref $name
Creating test-proposed
$ ./make-configdrive-dir $d $name
config-drive/
config-drive/openstack/
config-drive/openstack/latest/
config-drive/openstack/latest/meta_data.json
config-drive/openstack/latest/vendor_data.json
config-drive/openstack/latest/user_data
config-drive/openstack/2015-10-15/
config-drive/openstack/2015-10-15/meta_data.json
config-drive/openstack/2015-10-15/vendor_data.json
config-drive/openstack/2015-10-15/user_data
$ rm -Rf $d
$ lxc file pull $name/etc/cloud/cloud.cfg.d/90_dpkg.cfg - | sed 's/NoCloud, //' | lxc file push - $name/etc/cloud/cloud.cfg.d/90_dpkg.cfg
$ lxc exec $name -- sudo DEBUG_LEVEL=2 DI_LOG=stderr /usr/lib/cloud-init/ds-identify --force 2>&1 | egrep 'latest|Found'
config drive seeded directory had only 'latest'
config drive seeded directory had only 'latest'
Found single datasource: ConfigDrive
$ lxc exec $name -- dpkg -l cloud-init
...
ii cloud-init 0.7.9-113-g5 all Init scripts for cloud instances