I totally get the attraction of learning one set of tooling, rather than k8s and ami/homebrew. Blue/green deploys are nice, particularly because we deploy for most PRs.
But it just seems like you're trying to shove a very stateful management problem (the schema, the associated storage) into a system designed for mostly stateless stuff. And that way lies a giant hassle.
Plus we're certainly not at huge scale, but db rollbacks are nontrivial, and we have to be somewhat careful about schema modifications.
But Kubernetes _is_ designed to support stateful containers; that's what StatefulSets are about.
There's nothing about containers that says they need to be stateless, it's just more convenient that way because you can treat every container as expendable, redundant, fungible commodities. But the real world needs state, and Kubernetes is capable of managing it. In particular, the pattern pretty much required for stateful apps on Kubernetes is that of using an exclusive-access network block device. Since only one container (or pod) can mount it at any given time, you can ensure that the state follows the container around.
I understand it can be done; it just seems like a hassle (viz this thread!) and I don't understand the upside. Discovery is an upside, but I bet there's a way to get discovery with manual updates.
It may just be our use case -- we have enough data (low TB) that cloning is not a fast thing to do.
But it just seems like you're trying to shove a very stateful management problem (the schema, the associated storage) into a system designed for mostly stateless stuff. And that way lies a giant hassle.
Plus we're certainly not at huge scale, but db rollbacks are nontrivial, and we have to be somewhat careful about schema modifications.
Thanks for your comment!