OK - with https://review.openstack.org/#/c/418521/ we have at least a working POC of what we can do. The issue is that we're running into the Zuul timeout. Depending on how quickly the AIO is built, we can get to the point where we run the upgrade script[2]. However in some runs we don't get to the end of the AIO build[3]. So, the question is, how do we proceed? I'm not a real LXC expert but if we could somehow cache stable builds of the LXC containers, so that bootstrapping the AIO just means downloading and launching them, so that we can use the majority of the Zuul runtime to execute the upgrade script, that'd be great. I know he have diskimage builder that does something sort of like this, maybe we can do something similar for the LXC containers? [1]: http://logs.openstack.org/21/418521/7/experimental/gate-openstack-ansible-openstack-ansible-upgrade-ubuntu-xenial-nv/6704087/console.html#_2017-01-11_05_13_16_114022 [2]: http://logs.openstack.org/21/418521/7/experimental/gate-openstack-ansible-openstack-ansible-upgrade-ubuntu-xenial-nv/6704087/console.html#_2017-01-11_05_13_24_895056 [3]: http://logs.openstack.org/21/418521/8/experimental/gate-openstack-ansible-openstack-ansible-upgrade-ubuntu-xenial-nv/ac09458/console.html#_2017-01-11_21_13_55_572404 -- Sean M. Collins