$ lxd-images import ubuntu --alias ubuntu --sync
Downloading the GPG key for http://cloud-images.ubuntu.com
Validating the GPG signature of /tmp/tmpmwfxoqzj/download.json.asc
Downloading the image.
Image manifest: http://cloud-images.ubuntu.com/server/releases/trusty/release-20160114.5/ubuntu-14.04-server-cloudimg-amd64.manifest
Image imported as: 1032903165a677e18ed93bde5057ae6287841ae756d1a6296eef8f2e5a825e4a
Setup alias: ubuntu
$ lxc launch ubuntu test
Creating test done.
Starting test done.
$ lxc exec test bash
root@test:~# dpkg -l | grep six
ii  python-six                       1.5.2-1ubuntu1                   all          Python 2 and 3 compatibility library (Python 2 interface)
root@test:~#