On Mon, 2016-03-28 at 09:27 -0400, Colin Walters wrote: > Hi, > > In some of my use cases I have OpenShift/Kubernetes clusters that are > primarily certified on 1.9, and so I'd like to keep using that. But > it'd be useful to be able to quickly try out 1.10 on some of my > nodes, or in cases outside of a Kube cluster. > > Does anyone have any thoughts on this? What if we had two Docker > packages, and used a config option to determine which to run as > `docker.service` ?
I personally see little value in the engineering effort required to install two versions at once. There just don't seem to me to be many practical use cases. Actual users, people who need to get work done with docker will not want to constantly flip back and forth. Docker developers aren't like to want to do so as they are likely to just want to work on the latest and greatest. Which leaves me only able to think of the one oddball case you already pointed out. Where kubernetes only claims support for 1.9 even though Docker has released 1.10. Where a user may want to evaluate using plain docker vs using kubernetes. In this situation you either have the case where the user needs a feature in $KUBE_DOCKER_VERSION + 1, and they both cannot use kube and cannot use $KUBE_DOCKER_VERSION or they do not need a docker feature in $VERSION+1 in which case they should be able to do the comparison with only 1 version installed. So I don't see a real reason to need 2 versions installed from a user story point of view. And the fact that there is only one version of docker supported in a fedora release at a time leads bolsters my feelings like this is not something a user would need/want. In which case it makes me ask 'obviously I'm missing the point, why is someone asking for this?' I can only assume it is because of the pain involved in changing the version of a package when using rpmostree as a developer. Which makes me ask, 'should we be using atomic in this case?' When the explicit use case is about quickly iterating between two versions of packages and rpmostree is about entire images, it just seems like we have an impeedance mismatch which maybe shouldn't be 'solved'... -Eric