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