The tripleo-validations are executed from the mistral_executor container. Some validations check out multiple services config files located in /var/lib/config-data/puppet-generated/ on the undercloud host. This container don't have access to this tree and those validations are failing. A bind-mount of this tree should be created for the mistral_executor.
Verified. [stack@undercloud-0 ~]$ rpm -q openstack-tripleo-heat-templates openstack-tripleo-heat-templates-9.0.1-0.20181013060903.el7ost.noarch
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-2019:0045