Validate library files for documentation string

The ansible library files should all have a DOCUMENTATION and EXAMPLES variables.
This commit makes the CI fail in case the variables are missing from the
files in 'validations/library' subdirectory.

Change-Id: Ibd38d893ed1ff0e1032c2f97c0eb1e71d3897ea4

tools/validate-files.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import argparse
+import os
+import sys
+
+
+def exit_usage():
+    print('Usage %s <directory>' % sys.argv[0])
+    sys.exit(1)
+
+
+def validate_library_file(file_path):
+    with open(file_path) as f:
+        file_content = f.read()
+        if 'DOCUMENTATION = ' not in file_content \
+                or 'EXAMPLES = ' not in file_content:
+            if quiet < 1:
+                print('Missing ansible documentation in %s' % file_path)
+            return 1
+    return 0
+
+
+def parse_args():
+    p = argparse.ArgumentParser()
+
+    p.add_argument('--quiet', '-q',
+                   action='count',
+                   help='output warnings and errors (-q) or only errors (-qq)')
+
+    p.add_argument('path_args',
+                   nargs='*',
+                   default=['.'])
+
+    return p.parse_args()
+
+args = parse_args()
+path_args = args.path_args
+quiet = args.quiet
+exit_val = 0
+failed_files = []
+
+for base_path in path_args:
+    if os.path.isdir(base_path):
+        for subdir, dirs, files in os.walk(base_path):
+            if '.tox' in dirs:
+                dirs.remove('.tox')
+            if '.git' in dirs:
+                dirs.remove('.git')
+            for f in files:
+                if f.endswith('.py') \
+                        and not f == '__init__.py' \
+                        and os.path.join('validations', 'library') in subdir:
+                    file_path = os.path.join(subdir, f)
+                    if quiet < 1:
+                        print('Validating %s' % file_path)
+                    failed = validate_library_file(file_path)
+                    if failed:
+                        failed_files.append(file_path)
+                    exit_val |= failed
+    else:
+        print('Unexpected argument %s' % base_path)
+        exit_usage()
+
+if failed_files:
+    print('Validation failed on:')
+    for f in failed_files:
+        print(f)
+else:
+    print('Validation successful!')
+sys.exit(exit_val)

tox.ini

@@ -16,7 +16,9 @@ whitelist_externals = bash
 commands = bash -c tools/releasenotes_tox.sh
 
 [testenv:pep8]
-commands = flake8 {posargs}
+commands =
+    flake8 {posargs}
+    python ./tools/validate-files.py .
 
 [testenv:venv]
 commands = {posargs}