Comment 6 for bug 1701325

Validated on lxc containers xenial and zesty:

$ for release in xenial zesty; do
        ref=$release-proposed;
        echo "$release START --------------";
        ./lxc-proposed-snapshot --proposed --publish $release $ref;
        lxc init $ref test-$release;
        lxc start test-$release;
        lxc sleep 10;
        lxc exec test-$release -- grep WARN /var/log/cloud-init.log;
        lxc exec test-$release -- dpkg-query --show cloud-init;
done

xenial START --------------
Creating xenial-proposed-123719471
...
# No WARN messages
cloud-init 0.7.9-233-ge586fe35-0ubuntu1~16.04.1

zesty START --------------
Creating zesty-proposed-34023523
...
The following packages will be upgraded:
  cloud-init
...
Get:1 http://archive.ubuntu.com/ubuntu zesty-proposed/main amd64 cloud-init all 0.7.9-233-ge586fe35-0ubuntu1~17.04.1 [321 kB]
...
# No WARN messages
cloud-init 0.7.9-233-ge586fe35-0ubuntu1~17.04.1