--- validated yakkety and zesty
$ for release in yakkety zesty; do  ref=$release-proposed; echo $ref; ./lxc-proposed-snapshot --proposed --publish $release $ref; lxc init $ref $name; lxc start $name; sleep 10; echo "---GREP FOR WARNINGS---"; lxc exec $name -- grep "warning: " /var/log/syslog; echo "---GREP FOR WARNINGS DONE ---"; echo "grep for cloud-init too..."; echo "---GREP FOR CLOUD-INIT LOGS---"; lxc exec $name -- grep cloud-init /var/log/syslog; echo "---GREP FOR CLOUD-INIT LOGS DONE---"; lxc exec $name -- dpkg -l cloud-init; lxc exec $name -- grep VERSION= /etc/os-version; lxc stop $name; lxc delete $name; done;

yakkety-proposed
Creating yakkety-proposed-45277423
...
Installing new version of config file /etc/rsyslog.d/21-cloudinit.conf ...
Container published with fingerprint: 67c066c34544ad7c776d01ff456445957cf17524a31a7ce2db9ed0b981041c6f
Creating proposed-test
---GREP FOR WARNINGS---
---GREP FOR WARNINGS DONE ---
grep for cloud-init too...
---GREP FOR CLOUD-INIT LOGS---
May 12 18:45:52 proposed-test cloud-init[481]: Generating locales (this might take a while)...
May 12 18:45:53 proposed-test cloud-init[481]:   en_US.UTF-8... done
May 12 18:45:53 proposed-test cloud-init[481]: Generation complete.
May 12 18:45:53 proposed-test cloud-init[481]: Cloud-init v. 0.7.9 running 'modules:config' at Fri, 12 May 2017 18:45:52 +0000. Up 6.0 seconds.
May 12 18:45:54 proposed-test cloud-init[544]: Cloud-init v. 0.7.9 running 'modules:final' at Fri, 12 May 2017 18:45:54 +0000. Up 8.0 seconds.
May 12 18:45:54 proposed-test cloud-init[544]: ci-info: no authorized ssh keys fingerprints found for user ubuntu.
May 12 18:45:54 proposed-test cloud-init[544]: Cloud-init v. 0.7.9 finished at Fri, 12 May 2017 18:45:54 +0000. Datasource DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net].  Up 8.0 seconds
---GREP FOR CLOUD-INIT LOGS DONE---
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version      Architecture Description
+++-==============-============-============-=================================
ii  cloud-init     0.7.9-113-g5 all          Init scripts for cloud instances
VERSION="16.10 (Yakkety Yak)"
zesty-proposed
Creating zesty-proposed-2769111851
--proposed --
Get:1 http://security.ubuntu.com/ubuntu zesty-security InRelease [89.2 kB]
...
Container published with fingerprint: 9e3594e39dbb7ebbb9ceb3c0c13aab22a2e54fbc99edd97422f0a4fa1c2863df
Creating proposed-test
---GREP FOR WARNINGS---
---GREP FOR WARNINGS DONE ---
grep for cloud-init too...
---GREP FOR CLOUD-INIT LOGS---
May 12 18:54:56 proposed-test systemd[1]: cloud-init.service: Failed to reset devices.list: Operation not permitted
May 12 18:54:56 proposed-test systemd[1]: cloud-init.service: Failed to set invocation ID on control group /system.slice/cloud-init.service, ignoring: Operation not permitted
May 12 18:54:57 proposed-test cloud-init[479]: Generating locales (this might take a while)...
May 12 18:54:58 proposed-test cloud-init[479]:   en_US.UTF-8... done
May 12 18:54:58 proposed-test cloud-init[479]: Generation complete.
May 12 18:54:58 proposed-test cloud-init[479]: Cloud-init v. 0.7.9 running 'modules:config' at Fri, 12 May 2017 18:54:57 +0000. Up 7.0 seconds.
May 12 18:54:59 proposed-test cloud-init[542]: Cloud-init v. 0.7.9 running 'modules:final' at Fri, 12 May 2017 18:54:59 +0000. Up 9.0 seconds.
May 12 18:54:59 proposed-test cloud-init[542]: ci-info: no authorized ssh keys fingerprints found for user ubuntu.
May 12 18:54:59 proposed-test cloud-init[542]: Cloud-init v. 0.7.9 finished at Fri, 12 May 2017 18:54:59 +0000. Datasource DataSourceNoCloud [seed=/var/lib/cloud/seed/nocloud-net][dsmode=net].  Up 9.0 seconds
---GREP FOR CLOUD-INIT LOGS DONE---
VERSION="17.04 (Zesty Zapus)"