Comment 16 for bug 1354694

$ release="xenial"
$ name="$release-1354694"
$ cat >user-data <<"EOF"
> #cloud-config
> users:
> - default
> - name: foobar
> gecos: "My User"
> groups: sudo, adm
> - name: wark
> groups: [sudo, adm]
> EOF
$ sleep 10
$ lxc exec $name -- groups foobar
error: not found
$ lxc launch "ubuntu-daily:$release" "$name" "--config=user.user-data=$(cat user-data)"
Creating xenial-1354694
Starting xenial-1354694
$ sleep 10
$ lxc exec $name -- groups foobar
groups: 'foobar': no such user
$ lxc exec $name -- groups wark
wark : wark adm sudo
$ lxc exec $name -- dpkg-query --show cloud-init
cloud-init 0.7.8-49-g9e904bb-0ubuntu1~16.04.4
$ lxc file pull $name/etc/cloud/build.info -
build_name: server
serial: 20170207
$ m=http://archive.ubuntu.com/ubuntu;
$ echo "deb $m $release-proposed main" | lxc file push - $name/etc/apt/sources.list.d/proposed.list
$ lxc exec $name -- sh -c 'apt update -q && apt install cloud-init' </dev/null
...
The following packages will be upgraded:
  cloud-init
1 upgraded, 0 newly installed, 0 to remove and 20 not upgraded.
...

$ lxc exec $name -- dpkg-query --show cloud-init
cloud-init 0.7.9-0ubuntu1~16.04.2
$ lxc exec $name -- sh -c 'cd /var/lib/cloud; for d in *; do [ "$d" = "seed" ] || rm -vRf "$d"; done'

$ lxc exec $name -- sh -c 'rm -f /var/log/cloud*'
$ lxc restart $name
$
$ lxc exec $name -- groups foobar
foobar : foobar adm sudo
$ lxc exec $name -- groups wark
wark : wark adm sudo
$ lxc exec $name -- grep WARN /var/log/cloud-init.log || echo no warn
no warn