mediagoblin/app.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 logging
  19
  20 from mediagoblin.routing import get_url_map, endpoint_to_controller
  21
  22 from werkzeug.wrappers import Request
  23 from werkzeug.exceptions import HTTPException, NotFound
  24
  25 from mediagoblin import meddleware, __version__
  26 from mediagoblin.tools import common, translate, template
  27 from mediagoblin.tools.response import render_http_exception
  28 from mediagoblin.tools.theme import register_themes
  29 from mediagoblin.tools import request as mg_request
  30 from mediagoblin.mg_globals import setup_globals
  31 from mediagoblin.init.celery import setup_celery_from_config
  32 from mediagoblin.init.plugins import setup_plugins
  33 from mediagoblin.init import (get_jinja_loader, get_staticdirector,
  34     setup_global_and_app_config, setup_locales, setup_workbench, setup_database,
  35     setup_storage, setup_beaker_cache)
  36 from mediagoblin.tools.pluginapi import PluginManager
  37
  38
  39 _log = logging.getLogger(__name__)
  40
  41
  42 class MediaGoblinApp(object):
  43     """
  44     WSGI application of MediaGoblin
  45
  46     ... this is the heart of the program!
  47     """
  48     def __init__(self, config_path, setup_celery=True):
  49         """
  50         Initialize the application based on a configuration file.
  51
  52         Arguments:
  53          - config_path: path to the configuration file we're opening.
  54          - setup_celery: whether or not to setup celery during init.
  55            (Note: setting 'celery_setup_elsewhere' also disables
  56            setting up celery.)
  57         """
  58         _log.info("GNU MediaGoblin %s main server starting", __version__)
  59         _log.debug("Using config file %s", config_path)
  60         ##############
  61         # Setup config
  62         ##############
  63
  64         # Open and setup the config
  65         global_config, app_config = setup_global_and_app_config(config_path)
  66
  67         ##########################################
  68         # Setup other connections / useful objects
  69         ##########################################
  70
  71         # load all available locales
  72         setup_locales()
  73
  74         # Set up plugins -- need to do this early so that plugins can
  75         # affect startup.
  76         _log.info("Setting up plugins.")
  77         setup_plugins()
  78
  79         # Set up the database
  80         self.connection, self.db = setup_database()
  81
  82         # Register themes
  83         self.theme_registry, self.current_theme = register_themes(app_config)
  84
  85         # Get the template environment
  86         self.template_loader = get_jinja_loader(
  87             app_config.get('local_templates'),
  88             self.current_theme,
  89             PluginManager().get_template_paths()
  90             )
  91
  92         # Set up storage systems
  93         self.public_store, self.queue_store = setup_storage()
  94
  95         # set up routing
  96         self.url_map = get_url_map()
  97
  98         # set up staticdirector tool
  99         self.staticdirector = get_staticdirector(app_config)
 100
 101         # set up caching
 102         self.cache = setup_beaker_cache()
 103
 104         # Setup celery, if appropriate
 105         if setup_celery and not app_config.get('celery_setup_elsewhere'):
 106             if os.environ.get('CELERY_ALWAYS_EAGER', 'false').lower() == 'true':
 107                 setup_celery_from_config(
 108                     app_config, global_config,
 109                     force_celery_always_eager=True)
 110             else:
 111                 setup_celery_from_config(app_config, global_config)
 112
 113         #######################################################
 114         # Insert appropriate things into mediagoblin.mg_globals
 115         #
 116         # certain properties need to be accessed globally eg from
 117         # validators, etc, which might not access to the request
 118         # object.
 119         #######################################################
 120
 121         setup_globals(app=self)
 122
 123         # Workbench *currently* only used by celery, so this only
 124         # matters in always eager mode :)
 125         setup_workbench()
 126
 127         # instantiate application meddleware
 128         self.meddleware = [common.import_component(m)(self)
 129                            for m in meddleware.ENABLED_MEDDLEWARE]
 130
 131     def call_backend(self, environ, start_response):
 132         request = Request(environ)
 133
 134         # Compatibility with django, use request.args preferrably
 135         request.GET = request.args
 136
 137         ## Routing / controller loading stuff
 138         map_adapter = self.url_map.bind_to_environ(request.environ)
 139
 140         # By using fcgi, mediagoblin can run under a base path
 141         # like /mediagoblin/. request.path_info contains the
 142         # path inside mediagoblin. If the something needs the
 143         # full path of the current page, that should include
 144         # the basepath.
 145         # Note: urlgen and routes are fine!
 146         request.full_path = environ["SCRIPT_NAME"] + request.path
 147         # python-routes uses SCRIPT_NAME. So let's use that too.
 148         # The other option would be:
 149         # request.full_path = environ["SCRIPT_URL"]
 150
 151         # Fix up environ for urlgen
 152         # See bug: https://bitbucket.org/bbangert/routes/issue/55/cache_hostinfo-breaks-on-https-off
 153         if environ.get('HTTPS', '').lower() == 'off':
 154             environ.pop('HTTPS')
 155
 156         ## Attach utilities to the request object
 157         # Do we really want to load this via middleware?  Maybe?
 158         request.session = request.environ['beaker.session']
 159         # Attach self as request.app
 160         # Also attach a few utilities from request.app for convenience?
 161         request.app = self
 162
 163         request.db = self.db
 164         request.staticdirect = self.staticdirector
 165
 166         request.locale = translate.get_locale_from_request(request)
 167         request.template_env = template.get_jinja_env(
 168             self.template_loader, request.locale)
 169
 170         def build_proxy(endpoint, **kw):
 171             try:
 172                 qualified = kw.pop('qualified')
 173             except KeyError:
 174                 qualified = False
 175
 176             return map_adapter.build(
 177                     endpoint,
 178                     values=dict(**kw),
 179                     force_external=qualified)
 180
 181         request.urlgen = build_proxy
 182
 183         mg_request.setup_user_in_request(request)
 184
 185         try:
 186             endpoint, url_values = map_adapter.match()
 187             request.matchdict = url_values
 188         except HTTPException as exc:
 189             # Stop and render exception
 190             return render_http_exception(
 191                 request, exc,
 192                 exc.get_description(environ))(environ, start_response)
 193
 194         controller = endpoint_to_controller(endpoint)
 195
 196         # pass the request through our meddleware classes
 197         try:
 198             for m in self.meddleware:
 199                 response = m.process_request(request, controller)
 200                 if response is not None:
 201                     return response(environ, start_response)
 202         except HTTPException as e:
 203             return render_http_exception(
 204                 request, e,
 205                 e.get_description(environ))(environ, start_response)
 206
 207         request.start_response = start_response
 208
 209         # get the Http response from the controller
 210         try:
 211             response = controller(request)
 212         except HTTPException as e:
 213             response = render_http_exception(
 214                 request, e, e.get_description(environ))
 215
 216         # pass the response through the meddlewares
 217         try:
 218             for m in self.meddleware[::-1]:
 219                 m.process_response(request, response)
 220         except HTTPException as e:
 221             response = render_http_exeption(
 222                 request, e, e.get_description(environ))
 223
 224         return response(environ, start_response)
 225
 226     def __call__(self, environ, start_response):
 227         ## If more errors happen that look like unclean sessions:
 228         # self.db.check_session_clean()
 229
 230         try:
 231             return self.call_backend(environ, start_response)
 232         finally:
 233             # Reset the sql session, so that the next request
 234             # gets a fresh session
 235             self.db.reset_after_request()
 236
 237
 238 def paste_app_factory(global_config, **app_config):
 239     configs = app_config['config'].split()
 240     mediagoblin_config = None
 241     for config in configs:
 242         if os.path.exists(config) and os.access(config, os.R_OK):
 243             mediagoblin_config = config
 244             break
 245
 246     if not mediagoblin_config:
 247         raise IOError("Usable mediagoblin config not found.")
 248
 249     mgoblin_app = MediaGoblinApp(mediagoblin_config)
 250
 251     return mgoblin_app