# SPDX-License-Identifier: AGPL-3.0-or-later # lint: pylint """This module implements the engine loader. Load and initialize the ``engines``, see :py:func:`load_engines` and register :py:obj:`engine_shortcuts`. usage:: load_engines( settings['engines'] ) """ import sys import copy from os.path import realpath, dirname from babel.localedata import locale_identifiers from searx import logger, settings from searx.data import ENGINES_LANGUAGES from searx.network import get from searx.utils import load_module, match_language, gen_useragent logger = logger.getChild('engines') ENGINE_DIR = dirname(realpath(__file__)) BABEL_LANGS = [ lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0] for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers()) ] ENGINE_DEFAULT_ARGS = { "engine_type": "online", "inactive": False, "disabled": False, "timeout": settings["outgoing"]["request_timeout"], "shortcut": "-", "categories": ["general"], "supported_languages": [], "language_aliases": {}, "paging": False, "safesearch": False, "time_range_support": False, "enable_http": False, "display_error_messages": True, "tokens": [], } """Defaults for the namespace of an engine module, see :py:func:`load_engine`""" categories = {'general': []} engines = {} engine_shortcuts = {} """Simple map of registered *shortcuts* to name of the engine (or ``None``). :: engine_shortcuts[engine.shortcut] = engine.name """ def load_engine(engine_data): """Load engine from ``engine_data``. :param dict engine_data: Attributes from YAML ``settings:engines/`` :return: initialized namespace of the ````. 1. create a namespace and load module of the ```` 2. update namespace with the defaults from :py:obj:`ENGINE_DEFAULT_ARGS` 3. update namespace with values from ``engine_data`` If engine *is active*, return namespace of the engine, otherwise return ``None``. This function also returns ``None`` if initialization of the namespace fails for one of the following reasons: - engine name contains underscore - engine name is not lowercase - required attribute is not set :py:func:`is_missing_required_attributes` """ engine_name = engine_data['name'] if '_' in engine_name: logger.error('Engine name contains underscore: "{}"'.format(engine_name)) return None if engine_name.lower() != engine_name: logger.warn('Engine name is not lowercase: "{}", converting to lowercase'.format(engine_name)) engine_name = engine_name.lower() engine_data['name'] = engine_name # load_module engine_module = engine_data['engine'] try: engine = load_module(engine_module + '.py', ENGINE_DIR) except (SyntaxError, KeyboardInterrupt, SystemExit, SystemError, ImportError, RuntimeError): logger.exception('Fatal exception in engine "{}"'.format(engine_module)) sys.exit(1) except BaseException: logger.exception('Cannot load engine "{}"'.format(engine_module)) return None update_engine_attributes(engine, engine_data) set_language_attributes(engine) update_attributes_for_tor(engine) if not is_engine_active(engine): return None if is_missing_required_attributes(engine): return None set_loggers(engine, engine_name) return engine def set_loggers(engine, engine_name): # set the logger for engine engine.logger = logger.getChild(engine_name) # the engine may have load some other engines # may sure the logger is initialized for module_name, module in sys.modules.items(): if ( module_name.startswith("searx.engines") and module_name != "searx.engines.__init__" and not hasattr(module, "logger") ): module_engine_name = module_name.split(".")[-1] module.logger = logger.getChild(module_engine_name) def update_engine_attributes(engine, engine_data): # set engine attributes from engine_data for param_name, param_value in engine_data.items(): if param_name == 'categories': if isinstance(param_value, str): param_value = list(map(str.strip, param_value.split(','))) engine.categories = param_value elif param_name != 'engine': setattr(engine, param_name, param_value) # set default attributes for arg_name, arg_value in ENGINE_DEFAULT_ARGS.items(): if not hasattr(engine, arg_name): setattr(engine, arg_name, copy.deepcopy(arg_value)) def set_language_attributes(engine): # pylint: disable=protected-access # assign supported languages from json file if engine.name in ENGINES_LANGUAGES: engine.supported_languages = ENGINES_LANGUAGES[engine.name] # find custom aliases for non standard language codes for engine_lang in engine.supported_languages: iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None) if (iso_lang and iso_lang != engine_lang and not engine_lang.startswith(iso_lang) and iso_lang not in engine.supported_languages ): engine.language_aliases[iso_lang] = engine_lang # language_support engine.language_support = len(engine.supported_languages) > 0 # assign language fetching method if auxiliary method exists if hasattr(engine, '_fetch_supported_languages'): headers = { 'User-Agent': gen_useragent(), 'Accept-Language': 'ja-JP,ja;q=0.8,en-US;q=0.5,en;q=0.3', # bing needs a non-English language } engine.fetch_supported_languages = ( lambda: engine._fetch_supported_languages( get(engine.supported_languages_url, headers=headers)) ) def update_attributes_for_tor(engine): if (settings['outgoing'].get('using_tor_proxy') and hasattr(engine, 'onion_url') ): engine.search_url = engine.onion_url + getattr(engine, 'search_path', '') engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0) def is_missing_required_attributes(engine): """An attribute is required when its name doesn't start with ``_`` (underline). Required attributes must not be ``None``. """ missing = False for engine_attr in dir(engine): if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None: logger.error( 'Missing engine config attribute: "{0}.{1}"' .format(engine.name, engine_attr)) missing = True return missing def is_engine_active(engine): # check if engine is inactive if engine.inactive is True: return False # exclude onion engines if not using tor if ('onions' in engine.categories and not settings['outgoing'].get('using_tor_proxy') ): return False return True def register_engine(engine): if engine.name in engines: logger.error('Engine config error: ambigious name: {0}'.format(engine.name)) sys.exit(1) engines[engine.name] = engine if engine.shortcut in engine_shortcuts: logger.error('Engine config error: ambigious shortcut: {0}'.format(engine.shortcut)) sys.exit(1) engine_shortcuts[engine.shortcut] = engine.name for category_name in engine.categories: categories.setdefault(category_name, []).append(engine) def load_engines(engine_list): """usage: ``engine_list = settings['engines']`` """ engines.clear() engine_shortcuts.clear() categories.clear() categories['general'] = [] for engine_data in engine_list: engine = load_engine(engine_data) if engine: register_engine(engine) return engines