Add docker local registry cleaning script

Since with changing data lists there are unused images
left in local registry on build server this
commit adds script that handles that.

Issue-ID: OOM-1952

Change-Id: Ied7a8b09aacd33ef17f0676cfab333d1df8a1a81
Signed-off-by: Milan Verespej <m.verespej@partner.samsung.com>
diff --git a/build/download/clean_docker_images.py b/build/download/clean_docker_images.py
new file mode 100755
index 0000000..186bfd6
--- /dev/null
+++ b/build/download/clean_docker_images.py
@@ -0,0 +1,71 @@
+#! /usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+#   COPYRIGHT NOTICE STARTS HERE
+
+#   Copyright 2019 © Samsung Electronics Co., Ltd.
+#
+#   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.
+
+#   COPYRIGHT NOTICE ENDS HERE
+
+
+import argparse
+import docker
+import logging
+import sys
+
+from downloader import AbstractDownloader
+from docker_downloader import DockerDownloader
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('image_lists', nargs='+', help='Images to keep')
+    parser.add_argument('--debug', '-d', action='store_true', help='Debugging messages')
+    args = parser.parse_args()
+
+    if args.debug:
+        logging.basicConfig(level=logging.DEBUG, stream=sys.stdout)
+    else:
+        logging.basicConfig(level=logging.INFO, stream=sys.stdout, format='%(message)s')
+
+    target = set()
+    for lst in args.image_lists:
+        target = target.union(AbstractDownloader.load_list(lst))
+
+    target = set(map(DockerDownloader.image_registry_name, target))
+
+    client = docker.client.DockerClient(version='auto')
+
+    errors = 0
+    for image in client.images.list():
+        for tag in image.tags:
+            logging.debug('Checking {}'.format(tag))
+            if tag not in target:
+                logging.debug('Image \'{}\' not in lists'.format(tag))
+                logging.info('Removing: {}'.format(tag))
+                try:
+                    client.images.remove(tag)
+                    logging.info('Removed: {}'.format(tag))
+                except docker.errors.APIError as err:
+                    errors += 1
+                    logging.exception(err)
+            else:
+                logging.debug('Image \'{}\' found in lists.'.format(tag))
+    sys.exit(errors)
+
+
+if __name__ == '__main__':
+    main()
+
diff --git a/build/download/downloader.py b/build/download/downloader.py
index 6440330..7aece0c 100644
--- a/build/download/downloader.py
+++ b/build/download/downloader.py
@@ -32,7 +32,7 @@
     def __init__(self, list_type, *list_args):
         self._list_type = list_type
         self._data_list = {item: list_arg[1] for list_arg in list_args
-                           for item in self._load_list(list_arg[0])}
+                           for item in self.load_list(list_arg[0])}
         self._missing = self.missing()
 
     @property
@@ -43,7 +43,7 @@
         return self._list_type
 
     @staticmethod
-    def _load_list(path):
+    def load_list(path):
         """
         Load list from file.
         :param path: path to file