Created attachment 1540272 [details]
full log of the failure

Description of problem:
Running deployment in dry run mode (only validating config files without actually deploying, performed by running ansible playbooks in check mode) fails while trying to run tripleo-ssh-known-hosts task, here the log:

TASK [tripleo-ssh-known-hosts : Create a temporary copy of ssh_known_hosts] ****
fatal: [controller-2]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'path'\n\nThe error appears to have been in '/usr/share/ansible/roles/tripleo-ssh-known-hosts/tasks/main.yml': line 12, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n      register: ssh_known_hosts_tmp\n    - name: Create a temporary copy of ssh_known_hosts\n      ^ here\n"}

Version-Release number of selected component (if applicable):


How reproducible:
Run overcloud deployment with dry-run flag

Steps to Reproduce:
1.
2.
3.

Actual results:
Validation fails because of undefined variable (see above)

Expected results:
All ansible playbooks should pass in check mode

Additional info:
https://rhos-qe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/view/DFG/view/df/view/rfe/job/DFG-df-rfe-14-virsh-3cont_2comp_3ceph-dry-run-verification/16/artifact/.sh/verification-run.log