Requesting multiple sidecar injections for pod about k8s-sidecar-injector HOT 3 CLOSED

@antimack the configmaps that drive the k8s-sidecar-injector are only ever consumed by the Sidecar Injector - pods themselves never refer to them.

from k8s-sidecar-injector.

Hey @antimack !

Great question - this was an explicit design decision I made when writing the injector initially. My thinking was that: while a technically possible and useful feature, it made me nervous about understandabiliity. Supporting "mixin" injections would be neat, but it becomes much more difficult to understand what the injected pod would look like when you need to union multiple injection configs in your head with your pod spec. Further, I was not sure there was an intuitive way to handle merging injection configs that have overlap (i.e. overlapping and conflicting env vars, volumes with diff mount flags, etc).

Ultimately, I wanted to make sure this was an uninteresting, uncomplicated part of our infrastructure, and not overly clever. We have internal uses that could benefit from multiple injections, but we instead maintain separate config files including the duplication. I have found its easier for new engineers to grok behavior with this design.

:) does that help answer your question?

from k8s-sidecar-injector.

Yes, indeed! Thanks for a quick reply. How do you guys manage ConfigMaps if for example your sidecar refers to them in env variable or volume and they need to be created before?

from k8s-sidecar-injector.