Note that if it fails to spin a host, it will stop. I think this is better
than continuing to the next, because there might be a reason to spin hosts
in some specific order (ie, update dns first and then use it).
Currently TERM is checked for every message. Could be memoized, but it
would add complexity, and typical propellor output is not going to be more
than a few hundred messages, and likely this will be swamped by the actual
work.
It might be better to do this check on boot to limit the time running the
DO kernel (which is not well security supported), but that has the
possibility of entering a bad reboot loop. Limiting this check to when
propellor runs avoids that, while still fixing the problem pretty fast.
The problem is it fell back to looking for an alias for the bad hostname,
but to get the aliases, it needs to know which hosts are docked where,
so looped.
This was using a lot of disk space. Instead, start the container, and then
use the running container to check if docker is running it with the right
params. In the unlikely case that the params have changed, we still need to
commit the container and restart it. The common case of eg a reboot no
longer commits though.
* Avoid encoding the current stable suite in propellor's code,
since that poses a difficult transition around the release,
and can easily be wrong if an older version of propellor is used.
Instead, the os property for a stable system includes the suite name
to use, eg Stable "wheezy".
* stdSourcesList uses the stable suite name, to avoid unwanted
immediate upgrades to the next stable release.