Print a warning when validation runs on zero nodes / print nodes used

[Attila Darazs]

Due to a dynamic inventory bug, no overcloud nodes got passed to the validation playbook. Despite this it returned with a message that implied that the validation ran successfully, despite not running at all on any nodes This is quite misleading. Would be better to print out the nodes it ran on for an improved output.

Example problem:

$ ./scripts/tripleo-ansible-inventory --list
{"undercloud": {"hosts": ["localhost"], "vars": {"ansible_connection": "local", "public_vip": "10.0.0.7"}}}
$ ansible-playbook -i scripts/tripleo-ansible-inventory validations/mysql-open-files-limit.yaml
Success! The validation passed for all hosts.

[Tomas Sedovic (tsedovic)]

In addition to that, if there is one host with a failure and all the others are successful, the summary message lists all hosts as failed.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/396135

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/396135
Committed: https://git.openstack.org/cgit/openstack/tripleo-validations/commit/?id=d6f10a2ab0272f1a7032559db67a74b38c966988
Submitter: Jenkins
Branch: master

commit d6f10a2ab0272f1a7032559db67a74b38c966988
Author: Katerina Pilatova <email address hidden>
Date: Thu Nov 10 12:44:26 2016 +0100

    callback_plugins/validation_output.py: improved output

    - when the validation is successful, all hosts are listed in the output
    - when the validation does not run on any host, output contains a warning
    - when the validation fails, both hosts where it passed and where it failed are listed

    Change-Id: I69368d2c56d4f014d0dde78b8662146fcf686751
    Closes-Bug: #1636849

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-validations 5.2.0 release.