Afuse is an automounting file system implemented in user-space
using FUSE.  Afuse  currently  implements  the  most  basic
functionality that can be expected by an automounter; that is it
manages a directory of virtual directories. If one of these virtual
directories is accessed and is not already automounted, afuse will
attempt  to  mount a  filesystem onto that directory. If the mount
succeeds the requested access proceeds as normal, otherwise it will
fail with an error.

The advantage of using afuse over traditional automounters is that
afuse is designed to run entirely in user-space by individual users.
This way an automounting action can take advantage of the invoking
users environment, for example allowing access to an ssh-agent for
password-less  sshfs  mounts,  or  allowing access to a  graphical
environment to get user input to complete a mount (i.e. popping up
a window asking for a password).

WWW: https://github.com/pcarrier/afuse