def load_paste_app(app_name=None):
"""Builds and returns a WSGI app from a paste config file.
We assume the last config file specified in the supplied ConfigOpts
object is the paste config file.
:param app_name: name of the application to load
:raises RuntimeError when config file cannot be located or application
cannot be loaded from config file
"""
if app_name is None:
app_name = CONF.prog
# append the deployment flavor to the application name,
# in order to identify the appropriate paste pipeline
app_name += _get_deployment_flavor()
conf_file = _get_deployment_config_file()
try:
logger = logging.getLogger(__name__)
logger.debug("Loading {app_name} from {conf_file}".format(
conf_file=conf_file, app_name=app_name))
app = deploy.loadapp("config:%s" % conf_file, name=app_name)
return app
except (LookupError, ImportError) as e:
msg = _("Unable to load %(app_name)s from configuration file"
" %(conf_file)s. \nGot: %(e)r") % {'conf_file': conf_file,
'app_name': app_name,
'e': e}
logger.error(msg)
raise RuntimeError(msg)
def _get_deployment_config_file():
"""Retrieve the deployment_config_file config item, formatted as an
absolute pathname.
"""
path = CONF.paste_deploy.config_file
if not path:
path = _get_paste_config_path()
if not path:
msg = _("Unable to locate paste config file for %s.") % CONF.prog
raise RuntimeError(msg)
return os.path.abspath(path)