NFS does not work on docker without a volume mount

Question

It works.

$ docker run --rm --net=host --privileged -v $PWD:/home -e SHARED_DIRECTORY=/home itsthenetwork/nfs-server-alpine

[..]

/home             <world>
Starting Mountd in the background...These
Startup successful.

It doesn't work.

$ docker run --rm --net=host --privileged -e SHARED_DIRECTORY=/home itsthenetwork/nfs-server-alpine

[..]

exportfs: /home does not support NFS export
Export validation failed, exiting...

I don't know why it's not working. The only difference is whether volume mount or not.

Please teach me.

Answer 1

self-solving

OverlayFS

OverlayFS does not support NFS export so please volume mount into your NFS container from an alternative (hopefully one is available).

On RancherOS the /home, /media and /mnt file systems are good choices as these are ext4.

https://hub.docker.com/r/itsthenetwork/nfs-server-alpine/