A change upstream to switch os-net-config to be installed via a package rather than via a DIB element accidently removed the openvswitch element that enables the openvswitch service by default on the overcloud. Prior to upstream Queens, the service was enabled so this was a regression.
guestfish -a /var/lib/libvirt/images/overcloud-full.qcow2 run : mount /dev/sda / : find /etc/systemd/system > master.txt
[root@sealusa9 ~]# cat master.txt |grep switch
virt-customize -a /var/lib/libvirt/images/overcloud-full.qcow2 --run-command "rpm -qa "*openvswitch*" > /root/file2"
[root@sealusa9 mnt]# cat /mnt/root/file2
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.