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