I had to install also python2-pecan-1.3.2-1.el7ost.noarch.rpm to bypass https://bugzilla.redhat.com/show_bug.cgi?id=1597622 , then overcloud stack deployed, but mistral deployment failed on what I believe is related to https://bugzilla.redhat.com/show_bug.cgi?id=1593345.
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.