Have a read here, I ran into a similar problem. Although I chose to mount the data store within Portainer and my compose stack. I used SMB, but you might be able to get some insight using NFS.
I do like this project very much, I spent weeks sometimes getting things to work together nicely - some of the implementation is not what I am accustomed to, but once you get the logic and understanding in place, it does begin to make sense 