The volume encryption in Nova was only ever designed to work with block device based volumes. Support for network attached volumes (RBD) or file based volumes (NFS) is a future RFE upstream, pending on QEMU support for LUKS. So the report is testing a feature which is known to not exist at this time. As such I'm marking this an RFE, since its not a bug.

Dan what's the state of the QEMU dependenc

QEMU has general support for LUKS encryption of raw files and block devices in QEMU 2.6.0 onwards, but to make effective use of it in OpenStack, particularly for NFS, we need qcow2 integration. That work is still pending.

(In reply to Daniel Berrange from comment #7)
> QEMU has general support for LUKS encryption of raw files and block devices
> in QEMU 2.6.0 onwards, but to make effective use of it in OpenStack,
> particularly for NFS, we need qcow2 integration. That work is still pending.


Native integration of LUKS and qcow2 is targeted at 7.4, adding bug 1406803 dependancy. 
Seam

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2018:2086