Dry run fails on container-registry : Check ftype

[Emilien Macchi]

Description of problem: when performing ansible check run it fails at task "container-registry : Check ftype"

Steps to Reproduce:
1. Deploy undercloud
2. Prepare for deployment, introspect & tag nodes
3. Add --stack-only to the overcloud_deploy.sh
4. Execute overcloud_deploy.sh
5. Generate ansible playbooks
6. Generate inventory file
7. Execute ansible-playbook with --check parameter

Actual results:

TASK [container-registry : Check ftype] ****************************************
fatal: [controller-2]: FAILED! => {"msg": "The conditional check 'ftype.stdout == 'ftype=0'' failed. The error was: error while evaluating conditional (ftype.stdout == 'ftype=0'): 'dict object' has no attribute 'stdout'\n\nThe error appears to have been in '/usr/share/ansible/roles/container-registry/tasks/docker.yml': line 42, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: Check ftype\n ^ here\n"}
fatal: [controller-1]: FAILED! => {"msg": "The conditional check 'ftype.stdout == 'ftype=0'' failed. The error was: error while evaluating conditional (ftype.stdout == 'ftype=0'): 'dict object' has no attribute 'stdout'\n\nThe error appears to have been in '/usr/share/ansible/roles/container-registry/tasks/docker.yml': line 42, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: Check ftype\n ^ here\n"}
fatal: [controller-0]: FAILED! => {"msg": "The conditional check 'ftype.stdout == 'ftype=0'' failed. The error was: error while evaluating conditional (ftype.stdout == 'ftype=0'): 'dict object' has no attribute 'stdout'\n\nThe error appears to have been in '/usr/share/ansible/roles/container-registry/tasks/docker.yml': line 42, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: Check ftype\n ^ here\n"}

NO MORE HOSTS LEFT *************************************************************
 to retry, use: --limit @/home/stack/config-download/deploy_steps_playbook.retry

PLAY RECAP *********************************************************************
compute-0 : ok=83 changed=29 unreachable=0 failed=0
compute-1 : ok=83 changed=29 unreachable=0 failed=0
controller-0 : ok=99 changed=42 unreachable=0 failed=1
controller-1 : ok=99 changed=42 unreachable=0 failed=1
controller-2 : ok=99 changed=42 unreachable=0 failed=1
undercloud : ok=2 changed=0 unreachable=0 failed=0

STDERR:

 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.
 [WARNING]: The loop variable 'item' is already in use. You should set the
`loop_var` value in the `loop_control` option for the task to something else to
avoid variable collisions and unexpected behavior.

Expected results:

Dry run should complete without errors

Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=1660475

[Emilien Macchi (emilienm)]

https://review.openstack.org/#/c/626149/