Issue 4954 - Implement a downloader script supporting OAuth2 authentication/authorization

sitescripts/oauth2dl/bin/oauth2dl.py

Index: sitescripts/oauth2dl/bin/oauth2dl.py
diff --git a/sitescripts/oauth2dl/bin/oauth2dl.py b/sitescripts/oauth2dl/bin/oauth2dl.py
new file mode 100644
index 0000000000000000000000000000000000000000..adeb085e63ebbc99f0261b615172822f3855b4c4
--- /dev/null
+++ b/sitescripts/oauth2dl/bin/oauth2dl.py
@@ -0,0 +1,111 @@
+# This file is part of the Adblock Plus web scripts,
+# Copyright (C) 2006-present eyeo GmbH
+#
+# Adblock Plus is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# Adblock Plus is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import argparse
+import io
+import os
+import sys
+import json
+
+from httplib2 import Http
+from oauth2client.service_account import ServiceAccountCredentials
+
+from sitescripts.oauth2dl.bin import constants as cnts
+
+
+def download_file(url, key_file, scope):
+    """Download a file using Oauth2.
+
+    Parameters
+    ----------
+    url: str
+        The url of the file we want to download
+    key_file: str
+        Path/ url to key file used in Oauth2
+    scope: str
+        The scope used in Oauth2
+
+    Returns
+    -------
+    dict
+        Headers resulted from the HTTP request.
+    str
+        Content of the file we want to download/ error message if unsuccessful.
+
+    """
+    credentials = ServiceAccountCredentials.from_json_keyfile_name(
+        key_file,
+        scopes=[scope],
+    )
+
+    http_auth = credentials.authorize(Http())
+
+    headers, content = http_auth.request(url)
+    try:
+        content = content.decode('utf-8')
+    finally:
+        return headers, content
+
+
+def parse_args():
+    """Set up the required arguments and returns them."""
+    parser = argparse.ArgumentParser(description='Download using Oauth2')
+
+    parser.add_argument('url', help='URL to download from')
+    parser.add_argument('-k', '--key', help='Oauth2 key file path',
+                        default=os.environ.get('OAUTH2DL_KEY'))
+    parser.add_argument('-s', '--scope', help='Oauth2 scope',
+                        default=os.environ.get('OAUTH2DL_SCOPE'))
+    parser.add_argument('-o', help='Path where to save the file.')
+
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    if args.key is None:
+        sys.exit(cnts.KEYFILE_NOT_FOUND_ERROR)
+
+    if args.scope is None:
+        sys.exit(cnts.SCOPE_NOT_FOUND_ERROR)
+
+    try:
+        headers, content = download_file(args.url, args.key, args.scope)
+    except KeyError as err:
+        sys.exit(cnts.INVALID_KEY_FILE.format(str(err), str(args.key)))
+    except Exception as err:
+        sys.exit(err)
+
+    if headers['status'] != '200':
+        try:
+            error_json = json.loads(content, encoding='utf-8')
+            sys.exit(cnts.GOOGLE_OAUTH_ERROR.format(
+                str(error_json['error']['code']),
+                str(error_json['error']['message']),
+            ))
+        except ValueError:
+            sys.exit(content)
+
+    if args.o is None:
+        sys.stdout.write(content)
+    else:
+        with io.open(args.o, encoding='utf-8', mode='wb') as f:
+            f.write(content)
+
+
+if __name__ == '__main__':
+    main()