The way tl-setup detects if the system supports NFS is very fragile as it checks for specific error messages from the mount command. This fragile system is now broken as mount now prints: > $ sudo mount -t nfs / / > mount: /: bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program. This is not among our expected error messages so we incorrectly assume the system supports NFS. This problem exists on at least RHEL 8, Fedora 34 and Ubuntu 20.04.
This change was introduced in v2.30, back in 2017. This is the specific commit: https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=e1706a6783c8b63fb66c4a065ad8ee3807bb5f2d Out of the current distributions only RHEL 7 has anything older. Even SLES 12 has v2.33.
Instead of the current fragile method we should be able to check for /sbin/mount.nfs. POSIX doesn't require this to exist, but util-linux has always required it and this is what the current documentation says: > For most types all the mount program has to do is issue a simple mount(2) > system call, and no detailed knowledge of the filesystem type is required. For > a few types however (like nfs, nfs4, cifs, smbfs, ncpfs) ad hoc code is > necessary. The nfs, nfs4, cifs, smbfs, and ncpfs filesystems have a separate > mount program. In order to make it possible to treat all types in a uniform > way, mount will execute the program /sbin/mount.TYPE (if that exists) when > called with type TYPE. As such it seems unlikely this will change in the future.
Detection now works correctly. Tested both with NFS support missing and available on RHEL 8 and Ubuntu 20.04 (for a total of four test runs).
Tested tl-setup on Ubuntu 18.04: ✓ The NFS module showed properly with missing packages in text mode ✓ The NFS module showed properly with missing packages in GUI mode ✓ The following packages were successfully installed: nfs-common libtirpc1 keyutils rpcbind libnfsidmap2 ✓ Local drives work ✓ The NFS module did not show once the packages were available And Ubuntu 21.04: ✓ The NFS module showed properly with missing packages in text mode ✓ The NFS module showed properly with missing packages in GUI mode ✓ The following packages were successfully installed: nfs-common keyutils rpcbind libnfsidmap2 ✓ Local drives work ✓ The NFS module did not show once the packages were available And RHEL7: ✓ The NFS module showed properly with missing packages in text mode ✓ The NFS module showed properly with missing packages in GUI mode ✓ The following packages were successfully installed: nfs-utils gssproxy keyutils libbasicobjects libcollection libevent libini_config libnfsidmap libpath_utils libref_array libverto-libevent quota quota-nls rpcbind tcp_wrappers ✓ Local drives work ✓ The NFS module did not show once the packages were available
