Should we use specific container versions or "latest"?

[jgresham]

so from what I know, we currently update to the latest docker image whenever we start the node, and it seems like this update feature is for specs; will it eventually do the docker image versions in addition to & separate from the specs?

good q... yeah this is the hard part to convey to users. We have 2 easy options:

1. leave imageTag as latest and just push a x.x.+1 bump to a spec file (controller). This should prompt the user to update the node.. stop/start .. and use the latest image. But it wouldnt show the user what is being updated.
2. we put the specific version for imageTag. This would probably be the best user experience as updates make sense this way. Then the only thing is that we would have to be updating spec files (controllers) everytime there is a client update.

Hard option:
3) I think we could use "latest" AND check/poll the docker container registry API to see what version "latest" is on the server and compare to local. But too much work for now

#2 is probably the best option imo. Updates will clearly show "geth 1.5 -> 1.6"

Another problem with #1 is that users could pull the latest container version and the controller (spec) isn't updated yet to handle potential breaking changes in the latest container version