Original title: Container + persistent storage: Cheapest and easiest for someone else to manage?

I have a rails app which is containerised (agnostic, but currently Docker) and (currently) uses the disk service for active storage (it has attachments). Are there any SaaS providers that would make this easy for someone not super technical to manage, w.r.t. pushing changes from a fork and providing cheap persistent storage (S3 compatible + a sql-compatible database option OR disk). I feel this is something that will require a level of compromise (e.g. splitting across multiple services) since this is a big ask. Initial setup can be more complicated as I can help with the transition, but should have good-enough support options ongoingly. I expect them to be able to pick up a lot. Any input much appreciated. Thank you!