Issue 2234 - Add a WSGI controller to collect email addresses for the Adblock Browser iOS launch

sitescripts/submitEmail/web/submitEmail.py

+# coding: utf-8
+
+# This file is part of the Adblock Plus web scripts,
+# Copyright (C) 2006-2015 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 fcntl
+import wsgiref.util
+from urlparse import parse_qs, urljoin
+from urllib import urlencode
+
+from sitescripts.utils import get_config, sendMail, encode_email_address
+from sitescripts.web import url_handler, form_handler
+from sitescripts.signing import sign, verify
+
+VERIFICATION_PATH = '/verifyEmail'
+
+@url_handler('/submitEmail')
+@form_handler
+def submit_email(environ, start_response, data):
+  email = data.get('email', '').strip()
+  try:
+    email = encode_email_address(email)
+  except ValueError:
+    start_response('400 Bad Request', [('Content-Type', 'text/plain')])
+    return ['No valid email address given.']
+
+  sendMail(
+    get_config().get('submit_email', 'verification_email_template'),
+    {
+      'recipient': email,
+      'verification_url': '%s?%s' % (
+        urljoin(wsgiref.util.application_uri(environ), VERIFICATION_PATH),
+        urlencode([('email', email), ('signature', sign(email))])
+      )
+    }
+  )
+
+  start_response('200 OK', [('Content-Type', 'text/plain')])
+  return ["Thanks for your submission! You'll receive a verification email shortly."]
+
+@url_handler(VERIFICATION_PATH)
+def verify_email(environ, start_response):
+  config = get_config()
+
+  params = parse_qs(environ.get('QUERY_STRING', ''))
+  email = params.get('email', [''])[0]
+  signature = params.get('signature', [''])[0]
+
+  if verify(email, signature):
+    filename = config.get('submit_email', 'filename')
+    with open(filename, 'a', 0) as file:
+      fcntl.lockf(file, fcntl.LOCK_EX)

[Wladimir Palant, 2015/04/23 16:04:40]

Will locks work correctly with append mode? I think that the file pointer is set
before you lock the file - meaning that once you get the lock you might not be
at the end of the file any more.

[Sebastian Noack, 2015/04/23 16:29:41]

It does work correctly on Linux. I tested it with two python shells opening the
the same file simultaneously in append mode. Despite the tell() method reporting
the position of the end of the file when it was opened, data written to the file
are still appended to the end of the file, behind other data that have been
written by the other process meanwhile.

+      try:
+        print >>file, email
+      finally:
+        fcntl.lockf(file, fcntl.LOCK_UN)
+
+    option = 'successful_verification_redirect_location'
+  else:
+    option = 'failed_verification_redirect_location'
+
+  start_response('303 See Other', [('Location', config.get('submit_email', option))])
+  return []