Using 'latest' means you have to first shut down running instances to pull.
(So an alternative to a tagging strategy, I suppose, would be to build, then shutdown, pull, and start. But it would be faster to stop/start without the pull.)
Okay, I'm not sure this is necessary any more. I'm pretty sure I can now build, pull, stop, and start. I think the problem was that I wasn't authenticating and pulling on each node individually.
Using 'latest' means you have to first shut down running instances to pull.
(So an alternative to a tagging strategy, I suppose, would be to build, then shutdown, pull, and start. But it would be faster to stop/start without the pull.)