kubernetes – Extremely strange behavior of kubectl exec for deployment/ vs

I am getting results that are really surprising me, and the docs aren’t helping me understand.

I have a deployment configured via kustomize.

There is currently 1 pod in the deployment.

I am getting different results for the following 2 commands, which I wouldn’t expect.

kubectl exec deployment/name -- sha256sum 

vs

kubectl exec  -- sha256sum 

I checked the ReplicaSets for the deployment. There are multiple ReplicaSets, but there is only one with a non-zero number of pods.

I suspect that kubernetes is somehow finding a non-gced container that in some sense still belongs to the deployment. This is incredibly non-intuitive, as that container doesn’t show up anywhere that I can see. I only can reason about its existence because of this strange action at a distance.

Happy to share more details if you think they’ll be relevant, but I seem to have distilled it down to its essence.