Source code for biothings.web.settings.configs


import importlib.util
import logging
import os
import types
from importlib import import_module
from typing import NamedTuple
from collections.abc import Collection


from . import default
from . import validators

logger = logging.getLogger(__name__)


[docs]def load(config="config"): config = load_module(config) if config.__name__ == config.__package__: attrs = [getattr(config, attr) for attr in dir(config)] confs = [attr for attr in attrs if isinstance(attr, types.ModuleType)] valis = ( validators.WebAPIValidator(), validators.DBParamValidator(), validators.SubmoduleValidator() ) return ConfigPackage( ConfigModule(config), [ ConfigModule(conf, config, valis) for conf in confs ]) else: # config is a single file module, not a package return ConfigModule(config, validators=( validators.WebAPIValidator(), validators.DBParamValidator() ))
[docs]def load_module(config, default=None): """ Load a config module. config: 1. a module object 2. a fully qualified module name 3. a file path to a module """ if isinstance(config, types.ModuleType): return config elif isinstance(config, str) and config.endswith('.py'): spec = importlib.util.spec_from_file_location("config", config) config = importlib.util.module_from_spec(spec) spec.loader.exec_module(config) return config elif isinstance(config, str) and config: return import_module(config) elif not config and default: return default raise ValueError(str(config))
# Opinion on item access [] # The ConfigModule is intended to present a interface similar to # types.ModuleType or types.SimpleNamespace, and hold primarily # known attributes that persisit throughout the application. For # those reasons, item-access interface is not supported.
[docs]class ConfigPackage(NamedTuple): root: object modules: Collection
[docs]class ConfigModule(): ''' A wrapper for the settings that configure the web API. * Environment variables can override settings of the same names. * Default values are defined in biothings.web.settings.default. ''' def __init__(self, config=None, parent=None, validators=(), **kwargs): self._fallback = parent # config package self._primary = config self._override = types.SimpleNamespace() logger.info("%s", self._primary) # log file location # process keyword setting override for key, value in kwargs.items(): setattr(self._override, key, value) # process environment variable override of named settings for name in os.environ: if hasattr(self, name): new_value = None if isinstance(getattr(self, name), str): new_value = os.environ[name] elif isinstance(getattr(self, name), bool): new_value = os.environ[name].lower() in ('true', '1') if new_value is not None: logger.info("$ %s = %s", name, os.environ[name]) setattr(self._override, name, new_value) else: # cannot override dict, array, object type... logger.error("Env %s is not suppored.", name) for validator in validators: validator.validate(self) def __getattr__(self, name): # transient settings like envs if hasattr(self._override, name): return getattr(self._override, name) # user specified config module elif hasattr(self._primary, name): return getattr(self._primary, name) # shared settings in a config package elif hasattr(self._fallback, name): return getattr(self._fallback, name) # global default settings elif hasattr(default, name): return getattr(default, name) else: # not provided and no default raise AttributeError(name)