Can an in-memory filesystem be created from inside a docker container with no special permissions? I'd like to create an in-memory filesystem within a docker container running on a cluster where I can't assign the container any special permissions (e.g. the container can't have CAP_SYS_ADMIN capability necessary for using mount).

Is it possible to create an in-memory filesystem under docker? Will one of the user space filesystems provide this functionality?

Reference article(s):


User Space File Systems
How do I mount --bind inside a Docker container?
FUSE inside Docker
An in-memory filesystem (ie, RAMDISK) using FUSE
Riofs - fuse device not found


UPDATE: After finding and reading the references added above it's looking more and more like the answer is a firm no. I'll leave this open a bit in case anyone wants to elaborate or correct me.
Kubernetes can mount a ram disk for you. The answer is right there in the standard RTFM guide. 

https://kubernetes.io/docs/concepts/storage/volumes/#emptydir

Create an emptyDir volume and set emptyDir.medium to "Memory" to build, what I interpret from the documentation to be, a dynamically sized memory file system which counts against the containers memory limit.

If you're not running under kubernetes, whatever system that deploys the docker container would need to create the ram disk and mount that into the container, or give the container the special permissions discussed in the various reference articles in the question.