mediagoblin/app.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 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 urllib
  19
  20 import routes
  21 from webob import Request, exc
  22
  23 from mediagoblin import routing, middleware
  24 from mediagoblin.tools import common, translate, template
  25 from mediagoblin.tools.response import render_404
  26 from mediagoblin.tools import request as mg_request
  27 from mediagoblin.mg_globals import setup_globals
  28 from mediagoblin.init.celery import setup_celery_from_config
  29 from mediagoblin.init import (get_jinja_loader, get_staticdirector,
  30     setup_global_and_app_config, setup_workbench, setup_database,
  31     setup_storage, setup_beaker_cache)
  32
  33
  34 class MediaGoblinApp(object):
  35     """
  36     WSGI application of MediaGoblin
  37
  38     ... this is the heart of the program!
  39     """
  40     def __init__(self, config_path, setup_celery=True):
  41         """
  42         Initialize the application based on a configuration file.
  43
  44         Arguments:
  45          - config_path: path to the configuration file we're opening.
  46          - setup_celery: whether or not to setup celery during init.
  47            (Note: setting 'celery_setup_elsewhere' also disables
  48            setting up celery.)
  49         """
  50         ##############
  51         # Setup config
  52         ##############
  53
  54         # Open and setup the config
  55         global_config, app_config = setup_global_and_app_config(config_path)
  56
  57         ##########################################
  58         # Setup other connections / useful objects
  59         ##########################################
  60
  61         # Set up the database
  62         self.connection, self.db = setup_database()
  63
  64         # Get the template environment
  65         self.template_loader = get_jinja_loader(
  66             app_config.get('user_template_path'))
  67
  68         # Set up storage systems
  69         self.public_store, self.queue_store = setup_storage()
  70
  71         # set up routing
  72         self.routing = routing.get_mapper()
  73
  74         # set up staticdirector tool
  75         self.staticdirector = get_staticdirector(app_config)
  76
  77         # set up caching
  78         self.cache = setup_beaker_cache()
  79
  80         # Setup celery, if appropriate
  81         if setup_celery and not app_config.get('celery_setup_elsewhere'):
  82             if os.environ.get('CELERY_ALWAYS_EAGER'):
  83                 setup_celery_from_config(
  84                     app_config, global_config,
  85                     force_celery_always_eager=True)
  86             else:
  87                 setup_celery_from_config(app_config, global_config)
  88
  89         #######################################################
  90         # Insert appropriate things into mediagoblin.mg_globals
  91         #
  92         # certain properties need to be accessed globally eg from
  93         # validators, etc, which might not access to the request
  94         # object.
  95         #######################################################
  96
  97         setup_globals(app = self)
  98
  99         # Workbench *currently* only used by celery, so this only
 100         # matters in always eager mode :)
 101         setup_workbench()
 102
 103         # instantiate application middleware
 104         self.middleware = [common.import_component(m)(self)
 105                            for m in middleware.ENABLED_MIDDLEWARE]
 106
 107
 108     def __call__(self, environ, start_response):
 109         request = Request(environ)
 110
 111         # pass the request through our middleware classes
 112         for m in self.middleware:
 113             response = m.process_request(request)
 114             if response is not None:
 115                 return response(environ, start_response)
 116
 117         ## Routing / controller loading stuff
 118         path_info = request.path_info
 119         route_match = self.routing.match(path_info)
 120
 121         # By using fcgi, mediagoblin can run under a base path
 122         # like /mediagoblin/. request.path_info contains the
 123         # path inside mediagoblin. If the something needs the
 124         # full path of the current page, that should include
 125         # the basepath.
 126         # Note: urlgen and routes are fine!
 127         request.full_path = environ["SCRIPT_NAME"] + request.path_info
 128         # python-routes uses SCRIPT_NAME. So let's use that too.
 129         # The other option would be:
 130         # request.full_path = environ["SCRIPT_URL"]
 131
 132         ## Attach utilities to the request object
 133         request.matchdict = route_match
 134         request.urlgen = routes.URLGenerator(self.routing, environ)
 135         # Do we really want to load this via middleware?  Maybe?
 136         request.session = request.environ['beaker.session']
 137         # Attach self as request.app
 138         # Also attach a few utilities from request.app for convenience?
 139         request.app = self
 140         request.locale = translate.get_locale_from_request(request)
 141
 142         request.template_env = template.get_jinja_env(
 143             self.template_loader, request.locale)
 144         request.db = self.db
 145         request.staticdirect = self.staticdirector
 146
 147         mg_request.setup_user_in_request(request)
 148
 149         # No matching page?
 150         if route_match is None:
 151             # Try to do see if we have a match with a trailing slash
 152             # added and if so, redirect
 153             if not path_info.endswith('/') \
 154                     and request.method == 'GET' \
 155                     and self.routing.match(path_info + '/'):
 156                 new_path_info = path_info + '/'
 157                 if request.GET:
 158                     new_path_info = '%s?%s' % (
 159                         new_path_info, urllib.urlencode(request.GET))
 160                 redirect = exc.HTTPFound(location=new_path_info)
 161                 return request.get_response(redirect)(environ, start_response)
 162
 163             # Okay, no matches.  404 time!
 164             request.matchdict = {}  # in case our template expects it
 165             return render_404(request)(environ, start_response)
 166
 167         controller = common.import_component(route_match['controller'])
 168         request.start_response = start_response
 169
 170         # get the response from the controller
 171         response = controller(request)
 172
 173         # pass the response through the middleware
 174         for m in self.middleware[::-1]:
 175             m.process_response(request, response)
 176
 177         return response(environ, start_response)
 178
 179
 180 def paste_app_factory(global_config, **app_config):
 181     configs = app_config['config'].split()
 182     mediagoblin_config = None
 183     for config in configs:
 184         if os.path.exists(config) and os.access(config, os.R_OK):
 185             mediagoblin_config = config
 186             break
 187
 188     if not mediagoblin_config:
 189         raise IOError("Usable mediagoblin config not found.")
 190
 191     mgoblin_app = MediaGoblinApp(mediagoblin_config)
 192
 193     return mgoblin_app