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