Automatically create unique cache directories

[alan113696]

Tell us more about this new feature.

We have an application that benefits a lot from mountpoint caching. To support mounting multiple S3 buckets on the same host, we have to create independent cache directories on the host to avoid conflicts among multiple mountpoint processes. This has become a big chore to maintain the cache directories on our EC2 instances.

Currently, on the mount-s3 command-line, we pass in a top-level folder as the "parent" path for caching. Then, mountpoint creates a "mountpoint-cache" subfolder. Instead of a static subfolder name, is it possible to create a unique one? This would let me specify just the parent path for caching on all mountpoint instances on the same host, and have mountpoint take care of creating a unique subfolder to avoid conflict.

This would also make it easier to deploy to Kubernetes using the CSI driver. Multiple Persistent Volumes (PVs) can specify the same parent cache directory, and independent subfolders are created per mount.

[arsh]

Thanks for opening this issue @alan113696. We'll discuss this internally and assign it a priority relative to other issues we have open and report back on next steps.