Set env vars in rc or pod manifest

[mboersma]

Instead of doing a programmatic docker build to add on last-mile environment variables, the k8s.py scheduler code could instead add them to the configuration / manifest it creates. docker.sock would still be necessary to pull images and push them to deis-registry, but this could be simpler and more efficient for the last-mile layer.

[bacongobbler]

We considered this but thought of it as a security concern at one point, but I'm not sure why. It doesn't matter where we store that metadata internally in the cluster, just as long as it stays internal. I'm +1 on this idea, since it will dramatically simplify the "magic" behind the scenes.

[helgi]

Would be fine with just dumping it all into env for now and then later we can look into combining secrets into it somehow? There is a GH issue on k8s to expose secrets as env but it's still in the works. We could do a little scripty injection to achieve that if we wanted to support that adhoc.

Thinking deis config:set hello=secret --secret kind of dealio and it would know what to do it it correctly

Would spin that off into a separate ticket

[bacongobbler]

yes, I think that's fine for now.

[helgi]

kubernetes/kubernetes#4710 is the ticket I was referring to upstream

[helgi]

Looks like we are already seeding ENV Vars into k8s RC templates (the pod portion of them). Happened as part of another ticket. That work also specifically added DEIS_APP and DEIS_RELEASE.

I did a PR that drops those parts (needs proper testing)