It seems like there's two main classes of data in farmOS;

1. System configuration: data that controls how farmOS behaves - e.g. module files, which modules are enabled, module settings, menus, etc.
2. Payload: data which is managed within farmOS and changes as part of normal day-to-day usage - e.g. users, assets, logs, file uploads, etc.

I think a pretty sane configuration for hosting farmOS in k8s would be building an image which captures all the "system configuration" parts internally (perhaps serving them from sqlite) but offloads the "payload" state to an external DB and S3-compatible API (S3/GCS/etc)