I just spent some time with the s3 protocol and I agree completely. What should have been able to leverage the simplifying assumptions turned into another hodgepodge. It’s not like nfs is a real shining example of simplicity either. I’ve never worked with p9, but potentially that aside I think we really failed to come up with a decent distributed file model,
If all the "popular" solutions are complex, it means the problem domain is complex.
You either are doomed to reimplement and rediscover the complexity on your own, or you change your requirements to fit a narrower problem domain to avoid (some of) the complexity.
I'm working on a distributed S3 cache that supports just two functions, pread style contents of a file and all the elements in a directory. I've worked on other systems that represents this entire structure as RDF triples, which leaves you with just query and insert. To come at it from another direction EFS only implements about 2/3 of NFSv4, and S3 was perfectly functional before they larded it up with all this policy stuff.
I'm not saying that there weren't reasons to add these functions to the protocol, but if your aim is minimalism, then you can do _much_ better, and I think there is a real benefit in having a bare bones protocol that anyone could implement in many contexts.
It was simple(ish) 20 years ago, to be fair.
Simpler than it is now, but the authentication system was never simple. You can't just put a bearer token in the authorization header, you have to follow a complicated algorithm to sign the request. That made some sense 20 years ago when s3 didn't use tls to protect against a mitm that changed the changed the request. It is less valuable now when you use tls.
Isn't the whole signed request part a hard requirement for 3rd party access? S3 was originally designed for web use, which means giving not-fully-trusted browsers some access to your storage bucket.
You can't exactly do "this client is allowed to download this one specific file for the next 24 hours (but not use it like their personal CDN and share the link with everyone)" or "this client is allowed to upload a single image file up to 10MB (but not upload a 100GB copy of Friends)" with basic bearer tokens.
Aside from the fact that you can do this statelessly (you could stuff a JWT or moral equivalent in the header as a Bearer token), if you were okay with server-side state, you can have the token be related to a principal or have permissions in of itself.
Of course you can do all that with a basic bearer token. It’s just a signed json object with an expiration