[mod] searx.engines.load_engine return None instead of sys.exit(1)

Loading an engine should not exit the application (*). Instead
of exit, return None.

(*) RuntimeError still exit the application: syntax error, etc...

BTW: add documentation and normalize indentation (no functional change)

Suggested-by: @dalf https://github.com/searxng/searxng/pull/116#issuecomment-851865627
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
This commit is contained in:
Markus Heiser 2021-06-01 13:34:41 +02:00 committed by Alexandre Flament
parent 70a9208972
commit 8908937046

View file

@ -1,10 +1,15 @@
# SPDX-License-Identifier: AGPL-3.0-or-later # SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint # lint: pylint
# pylint: disable=missing-function-docstring # pylint: disable=missing-function-docstring
""" """This module implements the engine loader.
Engine loader:
call load_engines(settings['engines]) Load and initialize the ``engines``, see :py:func:`load_engines` and register
to initialiaze categories, engines, engine_shortcuts :py:obj:`engine_shortcuts`.
usage::
load_engines( settings['engines'] )
""" """
import sys import sys
@ -20,8 +25,10 @@ from searx.utils import load_module, match_language, gen_useragent
logger = logger.getChild('engines') logger = logger.getChild('engines')
ENGINE_DIR = dirname(realpath(__file__)) ENGINE_DIR = dirname(realpath(__file__))
BABEL_LANGS = [lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0] BABEL_LANGS = [
for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers())] 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_DEFAULT_ARGS = {
"engine_type": "online", "engine_type": "online",
"inactive": False, "inactive": False,
@ -38,16 +45,45 @@ ENGINE_DEFAULT_ARGS = {
"display_error_messages": True, "display_error_messages": True,
"tokens": [], "tokens": [],
} }
"""Defaults for the namespace of an engine module, see :py:func:`load_engine`"""
categories = {'general': []} categories = {'general': []}
engines = {} engines = {}
engine_shortcuts = {} 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): def load_engine(engine_data):
"""Load engine from ``engine_data``.
:param dict engine_data: Attributes from YAML ``settings:engines/<engine>``
:return: initialized namespace of the ``<engine>``.
1. create a namespace and load module of the ``<engine>``
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'] engine_name = engine_data['name']
if '_' in engine_name: if '_' in engine_name:
logger.error('Engine name contains underscore: "{}"'.format(engine_name)) logger.error('Engine name contains underscore: "{}"'.format(engine_name))
sys.exit(1) return None
if engine_name.lower() != engine_name: if engine_name.lower() != engine_name:
logger.warn('Engine name is not lowercase: "{}", converting to lowercase'.format(engine_name)) logger.warn('Engine name is not lowercase: "{}", converting to lowercase'.format(engine_name))
@ -69,10 +105,12 @@ def load_engine(engine_data):
set_language_attributes(engine) set_language_attributes(engine)
update_attributes_for_tor(engine) update_attributes_for_tor(engine)
if is_missing_required_attributes(engine):
sys.exit(1)
if not is_engine_active(engine): if not is_engine_active(engine):
return None return None
if is_missing_required_attributes(engine):
return None
return engine return engine
@ -101,8 +139,11 @@ def set_language_attributes(engine):
# find custom aliases for non standard language codes # find custom aliases for non standard language codes
for engine_lang in engine.supported_languages: for engine_lang in engine.supported_languages:
iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None) 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 \ if (iso_lang
iso_lang not in engine.supported_languages: 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 engine.language_aliases[iso_lang] = engine_lang
# language_support # language_support
@ -114,25 +155,30 @@ def set_language_attributes(engine):
'User-Agent': gen_useragent(), '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 '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 =\ engine.fetch_supported_languages = (
lambda: engine._fetch_supported_languages(get(engine.supported_languages_url, headers=headers)) lambda: engine._fetch_supported_languages(
get(engine.supported_languages_url, headers=headers))
)
def update_attributes_for_tor(engine): def update_attributes_for_tor(engine):
if settings['outgoing'].get('using_tor_proxy') and hasattr(engine, 'onion_url'): if (settings['outgoing'].get('using_tor_proxy')
and hasattr(engine, 'onion_url') ):
engine.search_url = engine.onion_url + getattr(engine, 'search_path', '') engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')
engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0) engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0)
def is_missing_required_attributes(engine): def is_missing_required_attributes(engine):
"""an attribute is required when its name doesn't start with '_'. """An attribute is required when its name doesn't start with ``_`` (underline).
Required attributes must not be None Required attributes must not be ``None``.
""" """
missing = False missing = False
for engine_attr in dir(engine): for engine_attr in dir(engine):
if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None: if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None:
logger.error('Missing engine config attribute: "{0}.{1}"' logger.error(
.format(engine.name, engine_attr)) 'Missing engine config attribute: "{0}.{1}"'
.format(engine.name, engine_attr))
missing = True missing = True
return missing return missing
@ -143,7 +189,8 @@ def is_engine_active(engine):
return False return False
# exclude onion engines if not using tor # exclude onion engines if not using tor
if 'onions' in engine.categories and not settings['outgoing'].get('using_tor_proxy'): if ('onions' in engine.categories
and not settings['outgoing'].get('using_tor_proxy') ):
return False return False
return True return True
@ -160,7 +207,7 @@ def register_engine(engine):
def load_engines(engine_list): def load_engines(engine_list):
"""Use case: engine_list = settings['engines'] """usage: ``engine_list = settings['engines']``
""" """
engines.clear() engines.clear()
engine_shortcuts.clear() engine_shortcuts.clear()