*Thanos, Prometheus and Golang version used

My primary use case is to mount backups and then mount virtual machine images from inside them; but the latter cannot be achieved unless root is able to access the files.

This can be achieved by doing the mounting as root, but it is less convenient than just doing it as the same user.

Preferably the support would include also other standard mount options, as outlined in the fuse(8) manual pa

We need a small example showing how to use this function.

Is your feature request related to a problem? Please describe.
There is a need to cache certain directories outside the workspace. As it described in meltwater/drone-cache#106 (comment)

Describe the solution you'd like
Introduce a mode to enable absolute path mode if a given mount path starts with /.

cc @cmays20