searxng/searx/settings_defaults.py
czaky 122a9568de [network]: Add redundant parallel proxy requests.
Anecdotally, using SearX over unreliable proxies,
like tor, seems to be quite error prone.
SearX puts quite an effort to measure the
performance and reliability of engines, most
likely owning to those aspects being of
significant concern.

The patch here proposes to mitigate related
problems, by issuing concurrent redundant requests
through the specified proxies at once, returning
the first response that is not an error.
The functionality is enabled using the:
`proxy_request_redundancy` parameter within the
outgoing network settings or the engine settings.

Example:

```yaml

outgoing:
    request_timeout: 8.0
    proxies:
        "all://":
            - socks5h://tor:9050
            - socks5h://tor1:9050
            - socks5h://tor2:9050
            - socks5h://tor3:9050
    proxy_request_redundancy: 4
```

In this example, each network request will be
send 4 times, once through every proxy. The
first (non-error) response wins.

In my testing environment using several tor proxy
end-points, this approach almost entirely
removes engine errors related to timeouts
and denied requests. The latency of the
network system is also improved.

The implementation, uses a
`AsyncParallelTransport(httpx.AsyncBaseTransport)`
wrapper to wrap multiple sub-trasports,
and `asyncio.wait` to wait on the first completed
request.

The existing implementation of the network
proxy cycling has also been moved into the
`AsyncParallelTransport` class, which should
improve network client memoization and
performance.

TESTED:
- unit tests for the new functions and classes.
- tested on desktop PC with 10+ upstream proxies
    and comparable request redundancy.
2024-05-17 02:09:29 +00:00

250 lines
9.5 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
"""Implementation of the default settings.
"""
import typing
import numbers
import errno
import os
import logging
from base64 import b64decode
from os.path import dirname, abspath
from .sxng_locales import sxng_locales
searx_dir = abspath(dirname(__file__))
logger = logging.getLogger('searx')
OUTPUT_FORMATS = ['html', 'csv', 'json', 'rss']
SXNG_LOCALE_TAGS = ['all', 'auto'] + list(l[0] for l in sxng_locales)
SIMPLE_STYLE = ('auto', 'light', 'dark')
CATEGORIES_AS_TABS = {
'general': {},
'images': {},
'videos': {},
'news': {},
'map': {},
'music': {},
'it': {},
'science': {},
'files': {},
'social media': {},
}
STR_TO_BOOL = {
'0': False,
'false': False,
'off': False,
'1': True,
'true': True,
'on': True,
}
_UNDEFINED = object()
class SettingsValue:
"""Check and update a setting value"""
def __init__(
self,
type_definition: typing.Union[None, typing.Any, typing.Tuple[typing.Any]] = None,
default: typing.Any = None,
environ_name: str = None,
):
self.type_definition = (
type_definition if type_definition is None or isinstance(type_definition, tuple) else (type_definition,)
)
self.default = default
self.environ_name = environ_name
@property
def type_definition_repr(self):
types_str = [t.__name__ if isinstance(t, type) else repr(t) for t in self.type_definition]
return ', '.join(types_str)
def check_type_definition(self, value: typing.Any) -> None:
if value in self.type_definition:
return
type_list = tuple(t for t in self.type_definition if isinstance(t, type))
if not isinstance(value, type_list):
raise ValueError('The value has to be one of these types/values: {}'.format(self.type_definition_repr))
def __call__(self, value: typing.Any) -> typing.Any:
if value == _UNDEFINED:
value = self.default
# override existing value with environ
if self.environ_name and self.environ_name in os.environ:
value = os.environ[self.environ_name]
if self.type_definition == (bool,):
value = STR_TO_BOOL[value.lower()]
self.check_type_definition(value)
return value
class SettingSublistValue(SettingsValue):
"""Check the value is a sublist of type definition."""
def check_type_definition(self, value: typing.Any) -> typing.Any:
if not isinstance(value, list):
raise ValueError('The value has to a list')
for item in value:
if not item in self.type_definition[0]:
raise ValueError('{} not in {}'.format(item, self.type_definition))
class SettingsDirectoryValue(SettingsValue):
"""Check and update a setting value that is a directory path"""
def check_type_definition(self, value: typing.Any) -> typing.Any:
super().check_type_definition(value)
if not os.path.isdir(value):
raise FileNotFoundError(errno.ENOENT, os.strerror(errno.ENOENT), value)
def __call__(self, value: typing.Any) -> typing.Any:
if value == '':
value = self.default
return super().__call__(value)
class SettingsBytesValue(SettingsValue):
"""str are base64 decoded"""
def __call__(self, value: typing.Any) -> typing.Any:
if isinstance(value, str):
value = b64decode(value)
return super().__call__(value)
def apply_schema(settings, schema, path_list):
error = False
for key, value in schema.items():
if isinstance(value, SettingsValue):
try:
settings[key] = value(settings.get(key, _UNDEFINED))
except Exception as e: # pylint: disable=broad-except
# don't stop now: check other values
logger.error('%s: %s', '.'.join([*path_list, key]), e)
error = True
elif isinstance(value, dict):
error = error or apply_schema(settings.setdefault(key, {}), schema[key], [*path_list, key])
else:
settings.setdefault(key, value)
if len(path_list) == 0 and error:
raise ValueError('Invalid settings.yml')
return error
SCHEMA = {
'general': {
'debug': SettingsValue(bool, False, 'SEARXNG_DEBUG'),
'instance_name': SettingsValue(str, 'SearXNG'),
'privacypolicy_url': SettingsValue((None, False, str), None),
'contact_url': SettingsValue((None, False, str), None),
'donation_url': SettingsValue((bool, str), "https://docs.searxng.org/donate.html"),
'enable_metrics': SettingsValue(bool, True),
},
'brand': {
'issue_url': SettingsValue(str, 'https://github.com/searxng/searxng/issues'),
'new_issue_url': SettingsValue(str, 'https://github.com/searxng/searxng/issues/new'),
'docs_url': SettingsValue(str, 'https://docs.searxng.org'),
'public_instances': SettingsValue((False, str), 'https://searx.space'),
'wiki_url': SettingsValue(str, 'https://github.com/searxng/searxng/wiki'),
'custom': SettingsValue(dict, {'links': {}}),
},
'search': {
'safe_search': SettingsValue((0, 1, 2), 0),
'autocomplete': SettingsValue(str, ''),
'autocomplete_min': SettingsValue(int, 4),
'default_lang': SettingsValue(tuple(SXNG_LOCALE_TAGS + ['']), ''),
'languages': SettingSublistValue(SXNG_LOCALE_TAGS, SXNG_LOCALE_TAGS),
'ban_time_on_fail': SettingsValue(numbers.Real, 5),
'max_ban_time_on_fail': SettingsValue(numbers.Real, 120),
'suspended_times': {
'SearxEngineAccessDenied': SettingsValue(numbers.Real, 86400),
'SearxEngineCaptcha': SettingsValue(numbers.Real, 86400),
'SearxEngineTooManyRequests': SettingsValue(numbers.Real, 3600),
'cf_SearxEngineCaptcha': SettingsValue(numbers.Real, 1296000),
'cf_SearxEngineAccessDenied': SettingsValue(numbers.Real, 86400),
'recaptcha_SearxEngineCaptcha': SettingsValue(numbers.Real, 604800),
},
'formats': SettingsValue(list, OUTPUT_FORMATS),
'max_page': SettingsValue(int, 0),
},
'server': {
'port': SettingsValue((int, str), 8888, 'SEARXNG_PORT'),
'bind_address': SettingsValue(str, '127.0.0.1', 'SEARXNG_BIND_ADDRESS'),
'limiter': SettingsValue(bool, False),
'public_instance': SettingsValue(bool, False),
'secret_key': SettingsValue(str, environ_name='SEARXNG_SECRET'),
'base_url': SettingsValue((False, str), False, 'SEARXNG_BASE_URL'),
'image_proxy': SettingsValue(bool, False),
'http_protocol_version': SettingsValue(('1.0', '1.1'), '1.0'),
'method': SettingsValue(('POST', 'GET'), 'POST'),
'default_http_headers': SettingsValue(dict, {}),
},
'redis': {
'url': SettingsValue((None, False, str), False, 'SEARXNG_REDIS_URL'),
},
'ui': {
'static_path': SettingsDirectoryValue(str, os.path.join(searx_dir, 'static')),
'static_use_hash': SettingsValue(bool, False),
'templates_path': SettingsDirectoryValue(str, os.path.join(searx_dir, 'templates')),
'default_theme': SettingsValue(str, 'simple'),
'default_locale': SettingsValue(str, ''),
'theme_args': {
'simple_style': SettingsValue(SIMPLE_STYLE, 'auto'),
},
'center_alignment': SettingsValue(bool, False),
'results_on_new_tab': SettingsValue(bool, False),
'advanced_search': SettingsValue(bool, False),
'query_in_title': SettingsValue(bool, False),
'infinite_scroll': SettingsValue(bool, False),
'cache_url': SettingsValue(str, 'https://web.archive.org/web/'),
'search_on_category_select': SettingsValue(bool, True),
'hotkeys': SettingsValue(('default', 'vim'), 'default'),
},
'preferences': {
'lock': SettingsValue(list, []),
},
'outgoing': {
'useragent_suffix': SettingsValue(str, ''),
'request_timeout': SettingsValue(numbers.Real, 3.0),
'enable_http2': SettingsValue(bool, True),
'verify': SettingsValue((bool, str), True),
'max_request_timeout': SettingsValue((None, numbers.Real), None),
'pool_connections': SettingsValue(int, 100),
'pool_maxsize': SettingsValue(int, 10),
'keepalive_expiry': SettingsValue(numbers.Real, 5.0),
# default maximum redirect
# from https://github.com/psf/requests/blob/8c211a96cdbe9fe320d63d9e1ae15c5c07e179f8/requests/models.py#L55
'max_redirects': SettingsValue(int, 30),
'retries': SettingsValue(int, 0),
'proxies': SettingsValue((None, str, dict), None),
'proxy_request_redundancy': SettingsValue(int, 1),
'source_ips': SettingsValue((None, str, list), None),
# Tor configuration
'using_tor_proxy': SettingsValue(bool, False),
'extra_proxy_timeout': SettingsValue(int, 0),
'networks': {},
},
'result_proxy': {
'url': SettingsValue((None, str), None),
'key': SettingsBytesValue((None, bytes), None),
'proxify_results': SettingsValue(bool, False),
},
'plugins': SettingsValue(list, []),
'enabled_plugins': SettingsValue((None, list), None),
'checker': {
'off_when_debug': SettingsValue(bool, True, None),
'scheduling': SettingsValue((None, dict), None, None),
},
'categories_as_tabs': SettingsValue(dict, CATEGORIES_AS_TABS),
'engines': SettingsValue(list, []),
'doi_resolvers': {},
}
def settings_set_defaults(settings):
apply_schema(settings, SCHEMA, [])
return settings