Access internal hosts via apex proxy. From the compute nodes we first
open an SSH connection to apex, and then tunnel it through the HTTP
proxy with netcat.
This way we allow reaching internal GitLab repositories without
requiring the user to have credentials in the remote host, while we can
use multiple remotes to provide redundancy.
Don't wait to flush writes, as we don't care about consistency on a
crash:
> This option allows the NFS server to violate the NFS protocol and
> reply to requests before any changes made by that request have been
> committed to stable storage (e.g. disc drive).
>
> Using this option usually improves performance, but at the cost that
> an unclean server restart (i.e. a crash) can cause data to be lost or
> corrupted.
