def main(global_config, **settings):
""" This function returns a Pyramid WSGI application.
"""
authn_policy = AuthTktAuthenticationPolicy(
settings.get('authn_secret'), callback=groupfinder)
authz_policy = ACLAuthorizationPolicy()
engine = engine_from_config(settings, 'sqlalchemy.')
DBSession.configure(bind=engine)
config = Configurator(settings=settings,
root_factory='stockpot.security.RootFactory')
config.set_authentication_policy(authn_policy)
config.set_authorization_policy(authz_policy)
config.set_request_property(get_user, 'user', reify=True)
config.add_static_view('static', 'static', cache_max_age=3600)
config.include(default_routes)
config.include(user_routes, route_prefix='user')
config.include('pyramid_beaker')
config.include('velruse.providers.facebook')
config.setup_facebook_login_from_settings(prefix='facebook.')
config.scan()
return config.make_wsgi_app()
