I believe the lines below from the deploy log point to the issue. I bolded the important parts. It looks like it was unable to resolve the FQDN for the host. What output and return code do you get when you run "getent ahostsv4 v0.mydomain | grep v0.mydomain" on that machine?
2018-05-14 13:24:59,631-0400 DEBUG otopi.ovirt_hosted_engine_setup.ansible_utils ansible_utils._process_output:94 hostname_resolution_output: {'stderr_lines': [], u'changed': True, u'end': u'2018-05-14 13:24:58.914393', u'stdout': u'', u'cmd': u'getent ahostsv4 v0.mydomain | grep v0.mydomain', u'failed': True, u'delta': u'0:00:00.005743', u'stderr': u'', u'rc': 1, u'msg': u'non-zero return code', 'stdout_lines': [], u'start': u'2018-05-14 13:24:58.908650'}
2018-05-14 13:24:59,832-0400 INFO otopi.ovirt_hosted_engine_setup.ansible_utils ansible_utils._process_output:100 TASK [Check address resolution]
2018-05-14 13:25:00,133-0400 DEBUG otopi.ovirt_hosted_engine_setup.ansible_utils ansible_utils._process_output:94 {u'msg': u'Unable to resolve address\n', u'changed': False, u'_ansible_no_log': False}
2018-05-14 13:25:00,234-0400 ERROR otopi.ovirt_hosted_engine_setup.ansible_utils ansible_utils._process_output:98 fatal: [localhost]: FAILED! => {"changed": false, "msg": "Unable to resolve address\n"}
Additionally, work is underway to make the logs easier to read and more useful so that troubleshooting issues like this won't be as difficult in the future. I'm sorry for any frustration it's caused and appreciate you reaching out to work through the issue.