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
  21 from mediagoblin.tools.routing import endpoint_to_controller
  22
  23 from werkzeug.wrappers import Request
  24 from werkzeug.exceptions import HTTPException
  25 from werkzeug.routing import RequestRedirect
  26
  27 from mediagoblin import meddleware, __version__
  28 from mediagoblin.tools import common, session, translate, template
  29 from mediagoblin.tools.response import render_http_exception
  30 from mediagoblin.tools.theme import register_themes
  31 from mediagoblin.tools import request as mg_request
  32 from mediagoblin.media_types.tools import media_type_warning
  33 from mediagoblin.mg_globals import setup_globals
  34 from mediagoblin.init.celery import setup_celery_from_config
  35 from mediagoblin.init.plugins import setup_plugins
  36 from mediagoblin.init import (get_jinja_loader, get_staticdirector,
  37     setup_global_and_app_config, setup_locales, setup_workbench, setup_database,
  38     setup_storage)
  39 from mediagoblin.tools.pluginapi import PluginManager, hook_transform
  40 from mediagoblin.tools.crypto import setup_crypto
  41 from mediagoblin.auth.tools import check_auth_enabled, no_auth_logout
  42
  43
  44 _log = logging.getLogger(__name__)
  45
  46
  47 class MediaGoblinApp(object):
  48     """
  49     WSGI application of MediaGoblin
  50
  51     ... this is the heart of the program!
  52     """
  53     def __init__(self, config_path, setup_celery=True):
  54         """
  55         Initialize the application based on a configuration file.
  56
  57         Arguments:
  58          - config_path: path to the configuration file we're opening.
  59          - setup_celery: whether or not to setup celery during init.
  60            (Note: setting 'celery_setup_elsewhere' also disables
  61            setting up celery.)
  62         """
  63         _log.info("GNU MediaGoblin %s main server starting", __version__)
  64         _log.debug("Using config file %s", config_path)
  65         ##############
  66         # Setup config
  67         ##############
  68
  69         # Open and setup the config
  70         global_config, app_config = setup_global_and_app_config(config_path)
  71
  72         media_type_warning()
  73
  74         setup_crypto()
  75
  76         ##########################################
  77         # Setup other connections / useful objects
  78         ##########################################
  79
  80         # Setup Session Manager, not needed in celery
  81         self.session_manager = session.SessionManager()
  82
  83         # load all available locales
  84         setup_locales()
  85
  86         # Set up plugins -- need to do this early so that plugins can
  87         # affect startup.
  88         _log.info("Setting up plugins.")
  89         setup_plugins()
  90
  91         # Set up the database
  92         self.db = setup_database(app_config['run_migrations'])
  93
  94         # Register themes
  95         self.theme_registry, self.current_theme = register_themes(app_config)
  96
  97         # Get the template environment
  98         self.template_loader = get_jinja_loader(
  99             app_config.get('local_templates'),
 100             self.current_theme,
 101             PluginManager().get_template_paths()
 102             )
 103
 104         # Check if authentication plugin is enabled and respond accordingly.
 105         self.auth = check_auth_enabled()
 106         if not self.auth:
 107             app_config['allow_comments'] = False
 108
 109         # Set up storage systems
 110         self.public_store, self.queue_store = setup_storage()
 111
 112         # set up routing
 113         self.url_map = get_url_map()
 114
 115         # set up staticdirector tool
 116         self.staticdirector = get_staticdirector(app_config)
 117
 118         # Setup celery, if appropriate
 119         if setup_celery and not app_config.get('celery_setup_elsewhere'):
 120             if os.environ.get('CELERY_ALWAYS_EAGER', 'false').lower() == 'true':
 121                 setup_celery_from_config(
 122                     app_config, global_config,
 123                     force_celery_always_eager=True)
 124             else:
 125                 setup_celery_from_config(app_config, global_config)
 126
 127         #######################################################
 128         # Insert appropriate things into mediagoblin.mg_globals
 129         #
 130         # certain properties need to be accessed globally eg from
 131         # validators, etc, which might not access to the request
 132         # object.
 133         #######################################################
 134
 135         setup_globals(app=self)
 136
 137         # Workbench *currently* only used by celery, so this only
 138         # matters in always eager mode :)
 139         setup_workbench()
 140
 141         # instantiate application meddleware
 142         self.meddleware = [common.import_component(m)(self)
 143                            for m in meddleware.ENABLED_MEDDLEWARE]
 144
 145     def call_backend(self, environ, start_response):
 146         request = Request(environ)
 147
 148         # Compatibility with django, use request.args preferrably
 149         request.GET = request.args
 150
 151         ## Routing / controller loading stuff
 152         map_adapter = self.url_map.bind_to_environ(request.environ)
 153
 154         # By using fcgi, mediagoblin can run under a base path
 155         # like /mediagoblin/. request.path_info contains the
 156         # path inside mediagoblin. If the something needs the
 157         # full path of the current page, that should include
 158         # the basepath.
 159         # Note: urlgen and routes are fine!
 160         request.full_path = environ["SCRIPT_NAME"] + request.path
 161         # python-routes uses SCRIPT_NAME. So let's use that too.
 162         # The other option would be:
 163         # request.full_path = environ["SCRIPT_URL"]
 164
 165         # Fix up environ for urlgen
 166         # See bug: https://bitbucket.org/bbangert/routes/issue/55/cache_hostinfo-breaks-on-https-off
 167         if environ.get('HTTPS', '').lower() == 'off':
 168             environ.pop('HTTPS')
 169
 170         ## Attach utilities to the request object
 171         # Do we really want to load this via middleware?  Maybe?
 172         session_manager = self.session_manager
 173         request.session = session_manager.load_session_from_cookie(request)
 174         # Attach self as request.app
 175         # Also attach a few utilities from request.app for convenience?
 176         request.app = self
 177
 178         request.db = self.db
 179         request.staticdirect = self.staticdirector
 180
 181         request.locale = translate.get_locale_from_request(request)
 182         request.template_env = template.get_jinja_env(
 183             self.template_loader, request.locale)
 184
 185         def build_proxy(endpoint, **kw):
 186             try:
 187                 qualified = kw.pop('qualified')
 188             except KeyError:
 189                 qualified = False
 190
 191             return map_adapter.build(
 192                     endpoint,
 193                     values=dict(**kw),
 194                     force_external=qualified)
 195
 196         request.urlgen = build_proxy
 197
 198         # Log user out if authentication_disabled
 199         no_auth_logout(request)
 200
 201         mg_request.setup_user_in_request(request)
 202
 203         request.controller_name = None
 204         try:
 205             found_rule, url_values = map_adapter.match(return_rule=True)
 206             request.matchdict = url_values
 207         except RequestRedirect as response:
 208             # Deal with 301 responses eg due to missing final slash
 209             return response(environ, start_response)
 210         except HTTPException as exc:
 211             # Stop and render exception
 212             return render_http_exception(
 213                 request, exc,
 214                 exc.get_description(environ))(environ, start_response)
 215
 216         controller = endpoint_to_controller(found_rule)
 217         # Make a reference to the controller's symbolic name on the request...
 218         # used for lazy context modification
 219         request.controller_name = found_rule.endpoint
 220
 221         # pass the request through our meddleware classes
 222         try:
 223             for m in self.meddleware:
 224                 response = m.process_request(request, controller)
 225                 if response is not None:
 226                     return response(environ, start_response)
 227         except HTTPException as e:
 228             return render_http_exception(
 229                 request, e,
 230                 e.get_description(environ))(environ, start_response)
 231
 232         request.start_response = start_response
 233
 234         # get the Http response from the controller
 235         try:
 236             response = controller(request)
 237         except HTTPException as e:
 238             response = render_http_exception(
 239                 request, e, e.get_description(environ))
 240
 241         # pass the response through the meddlewares
 242         try:
 243             for m in self.meddleware[::-1]:
 244                 m.process_response(request, response)
 245         except HTTPException as e:
 246             response = render_http_exception(
 247                 request, e, e.get_description(environ))
 248
 249         session_manager.save_session_to_cookie(request.session,
 250                                                request, response)
 251
 252         return response(environ, start_response)
 253
 254     def __call__(self, environ, start_response):
 255         ## If more errors happen that look like unclean sessions:
 256         # self.db.check_session_clean()
 257
 258         try:
 259             return self.call_backend(environ, start_response)
 260         finally:
 261             # Reset the sql session, so that the next request
 262             # gets a fresh session
 263             self.db.reset_after_request()
 264
 265
 266 def paste_app_factory(global_config, **app_config):
 267     configs = app_config['config'].split()
 268     mediagoblin_config = None
 269     for config in configs:
 270         if os.path.exists(config) and os.access(config, os.R_OK):
 271             mediagoblin_config = config
 272             break
 273
 274     if not mediagoblin_config:
 275         raise IOError("Usable mediagoblin config not found.")
 276
 277     mgoblin_app = MediaGoblinApp(mediagoblin_config)
 278     mgoblin_app = hook_transform('wrap_wsgi', mgoblin_app)
 279
 280     return mgoblin_app