mediagoblin/tools/processing.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import logging
  18 import json
  19 import traceback
  20
  21 from urllib2 import urlopen, Request, HTTPError
  22 from urllib import urlencode
  23
  24 _log = logging.getLogger(__name__)
  25
  26 TESTS_CALLBACKS = {}
  27
  28
  29 def create_post_request(url, data, **kw):
  30     '''
  31     Issue a HTTP POST request.
  32
  33     Args:
  34         url: The URL to which the POST request should be issued
  35         data: The data to be send in the body of the request
  36         **kw:
  37         data_parser: The parser function that is used to parse the `data`
  38             argument
  39     '''
  40     data_parser = kw.get('data_parser', urlencode)
  41     headers = kw.get('headers', {})
  42
  43     return Request(url, data_parser(data), headers=headers)
  44
  45
  46 def json_processing_callback(entry):
  47     '''
  48     Send an HTTP post to the registered callback url, if any.
  49     '''
  50     if not entry.processing_metadata:
  51         _log.debug('No processing callback for {0}'.format(entry))
  52         return
  53
  54     url = entry.processing_metadata[0].callback_url
  55
  56     _log.debug('Sending processing callback for {0} ({1})'.format(
  57         entry,
  58         url))
  59
  60     headers = {
  61             'Content-Type': 'application/json'}
  62
  63     data = {
  64             'id': entry.id,
  65             'state': entry.state}
  66
  67     # Trigger testing mode, no callback will be sent
  68     if url.endswith('secrettestmediagoblinparam'):
  69         TESTS_CALLBACKS.update({url: data})
  70         return True
  71
  72     request = create_post_request(
  73             url,
  74             data,
  75             headers=headers,
  76             data_parser=json.dumps)
  77
  78     try:
  79         urlopen(request)
  80         _log.debug('Processing callback for {0} sent'.format(entry))
  81
  82         return True
  83     except HTTPError:
  84         _log.error('Failed to send callback: {0}'.format(
  85             traceback.format_exc()))
  86
  87         return False