Allow running a no-op validation

The idea here is to be able to run a validation
called np-op in order to test the framework in the CI.

Also we should create a group validation called no-op running
only this validation.

Change-Id: Ied6eaa4009d624737d2dfac8a61f3a273537ce13

doc/source/_exts/generate_validations_doc.py

@@ -96,7 +96,7 @@ def build_detail(group, validations):
 
 def setup(app):
     # Seed it with the known groups:
-    groups = set(('prep', 'pre-introspection',
+    groups = set(('no-op', 'prep', 'pre-introspection',
                   'pre-deployment', 'post-deployment',
                   'pre-update', 'pre-upgrade',
                   'post-upgrade', 'openshift-on-openstack'))

doc/source/readme.rst

@@ -42,6 +42,11 @@ the deployment stage they're should be run on.
 
 Validations can belong to multiple groups.
 
+No op
+~~~~
+
+A validation doing nothing for testing the framework
+
 Prep
 ~~~~
 

playbooks/no-op.yaml

@@ -0,0 +1,12 @@
+---
+- hosts: undercloud, overcloud
+  vars:
+    metadata:
+      name: NO-OP validation
+      description: >
+        A simple validation doing nothing in order to test that
+        the validations framework works.
+      groups:
+        - no-op
+  roles:
+    - no-op

roles/no-op/meta/main.yml

@@ -0,0 +1,27 @@
+galaxy_info:
+  author: TripleO Validations Team
+  company: Red Hat
+  license: Apache
+  min_ansible_version: 2.4
+
+  platforms:
+  - name: CentOS
+    versions:
+    - 7
+  - name: RHEL
+    versions:
+    - 7
+
+  categories:
+    - cloud
+    - baremetal
+    - system
+  galaxy_tags: []
+    # List tags for your role here, one per line. A tag is a keyword that describes
+    # and categorizes the role. Users find roles by searching for tags. Be sure to
+    # remove the '[]' above, if you add tags to this list.
+    #
+    # NOTE: A tag is limited to a single word comprised of alphanumeric characters.
+    #       Maximum 20 tags per role.
+
+dependencies: []

roles/no-op/tasks/main.yml

@@ -0,0 +1,4 @@
+---
+- name: Run a no-op validation everywhere
+  debug:
+    msg: "This is a no-op action for testing that the validations framework runs"

roles/no-op/vars/main.yml

@@ -0,0 +1,8 @@
+---
+metadata:
+  name: NO-OP validation
+  description: >
+    A simple validation doing nothing in order to test that
+    the validations framework works.
+  groups:
+    - no-op