Improve tempest-cleanup ansible role

The patch implements a new flag which will fail a job when any
resources were leaked - that can be used for verification that
tests are cleaning their resources after they are finished.

Change-Id: I212cdce9713c80491153b0bbdb313e75c1f96f1d
diff --git a/roles/tempest-cleanup/tasks/dry_run_checker.py b/roles/tempest-cleanup/tasks/dry_run_checker.py
new file mode 100644
index 0000000..9cd9a85
--- /dev/null
+++ b/roles/tempest-cleanup/tasks/dry_run_checker.py
@@ -0,0 +1,71 @@
+# Copyright 2020 Red Hat, Inc
+# All Rights Reserved.
+#
+# 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.
+
+"""
+Utility for content checking of a given dry_run.json file.
+"""
+
+import argparse
+import json
+import sys
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(__doc__)
+    parser.add_argument('--is-empty', action="store_true", dest='is_empty',
+                        default=False,
+                        help="""Are values of a given dry_run.json empty?""")
+    parser.add_argument('--file', dest='file', default=None, metavar='PATH',
+                        help="A path to a dry_run.json file.")
+    return parser
+
+
+def parse_arguments():
+    parser = get_parser()
+    args = parser.parse_args()
+    if not args.file:
+        sys.stderr.write('Path to a dry_run.json must be specified.\n')
+        sys.exit(1)
+    return args
+
+
+def load_json(path):
+    """Load json content from file addressed by path."""
+    try:
+        with open(path, 'rb') as json_file:
+            json_data = json.load(json_file)
+    except Exception as ex:
+        sys.exit(ex)
+    return json_data
+
+
+def are_values_empty(dry_run_content):
+    """Return true if values of dry_run.json are empty."""
+    for value in dry_run_content.values():
+        if value:
+            return False
+    return True
+
+
+def main():
+    args = parse_arguments()
+    content = load_json(args.file)
+    if args.is_empty:
+        if not are_values_empty(content):
+            sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()