We need to have a global variable that allows us to distinguish kubernetes installations from "normal" ones. Something like $wgIsContainerized, so that we can vary configurations, e.g. for allowing to use TCP for connecting to nutcracker, or to add/not add the onhost memcached configuration (for now).
Conclusion: https://gerrit.wikimedia.org/r/711186 established $wmfUsingKubernetes