Hi, to allow mounting additional filesystems, one needs mount.<type> helpers. mount looks for them (not documented, but for at least all versions I tried) in /sbin/fs.d. Of course that directory is not writeable on atomic hosts.
I propose we create /sbin/fs.d in the same way we create /usr/local/. That way, a container does not have to install an overlayfs on top of /sbin (or similar) to install the helper scripts. Thank you for your consideration, Tobias Florek