mediagoblin/init/celery/__init__.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 os
  18 import sys
  19
  20 from celery import Celery
  21
  22
  23 MANDATORY_CELERY_IMPORTS = ['mediagoblin.processing.task']
  24
  25 DEFAULT_SETTINGS_MODULE = 'mediagoblin.init.celery.dummy_settings_module'
  26
  27
  28 def get_celery_settings_dict(app_config, global_config,
  29                              force_celery_always_eager=False):
  30     """
  31     Get a celery settings dictionary from reading the config
  32     """
  33     if 'celery' in global_config:
  34         celery_conf = global_config['celery']
  35     else:
  36         celery_conf = {}
  37
  38     celery_settings = {}
  39
  40     # Add all celery settings from config
  41     for key, value in celery_conf.iteritems():
  42         celery_settings[key] = value
  43
  44     # TODO: use default result stuff here if it exists
  45
  46     # add mandatory celery imports
  47     celery_imports = celery_settings.setdefault('CELERY_IMPORTS', [])
  48     celery_imports.extend(MANDATORY_CELERY_IMPORTS)
  49
  50     if force_celery_always_eager:
  51         celery_settings['CELERY_ALWAYS_EAGER'] = True
  52         celery_settings['CELERY_EAGER_PROPAGATES_EXCEPTIONS'] = True
  53
  54     return celery_settings
  55
  56
  57 def setup_celery_app(app_config, global_config,
  58                      settings_module=DEFAULT_SETTINGS_MODULE,
  59                      force_celery_always_eager=False):
  60     """
  61     Setup celery without using terrible setup-celery-module hacks.
  62     """
  63     celery_settings = get_celery_settings_dict(
  64         app_config, global_config, force_celery_always_eager)
  65     celery_app = Celery()
  66     celery_app.config_from_object(celery_settings)
  67
  68
  69 def setup_celery_from_config(app_config, global_config,
  70                              settings_module=DEFAULT_SETTINGS_MODULE,
  71                              force_celery_always_eager=False,
  72                              set_environ=True):
  73     """
  74     Take a mediagoblin app config and try to set up a celery settings
  75     module from this.
  76
  77     Args:
  78     - app_config: the application config section
  79     - global_config: the entire ConfigObj loaded config, all sections
  80     - settings_module: the module to populate, as a string
  81     - force_celery_always_eager: whether or not to force celery into
  82       always eager mode; good for development and small installs
  83     - set_environ: if set, this will CELERY_CONFIG_MODULE to the
  84       settings_module
  85     """
  86     celery_settings = get_celery_settings_dict(
  87         app_config, global_config, force_celery_always_eager)
  88
  89     __import__(settings_module)
  90     this_module = sys.modules[settings_module]
  91
  92     for key, value in celery_settings.iteritems():
  93         setattr(this_module, key, value)
  94
  95     if set_environ:
  96         os.environ['CELERY_CONFIG_MODULE'] = settings_module