searxng/searx/network/network.py
2021-09-07 13:34:35 +02:00

322 lines
12 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
# pylint: disable=global-statement
# pylint: disable=missing-module-docstring, missing-class-docstring
import atexit
import asyncio
import ipaddress
from itertools import cycle
import httpx
from .client import new_client, get_loop
DEFAULT_NAME = '__DEFAULT__'
NETWORKS = {}
# requests compatibility when reading proxy settings from settings.yml
PROXY_PATTERN_MAPPING = {
'http': 'http://',
'https': 'https://',
'socks4': 'socks4://',
'socks5': 'socks5://',
'socks5h': 'socks5h://',
'http:': 'http://',
'https:': 'https://',
'socks4:': 'socks4://',
'socks5:': 'socks5://',
'socks5h:': 'socks5h://',
}
ADDRESS_MAPPING = {
'ipv4': '0.0.0.0',
'ipv6': '::'
}
class Network:
__slots__ = (
'enable_http', 'verify', 'enable_http2',
'max_connections', 'max_keepalive_connections', 'keepalive_expiry',
'local_addresses', 'proxies', 'max_redirects', 'retries', 'retry_on_http_error',
'_local_addresses_cycle', '_proxies_cycle', '_clients'
)
def __init__(
# pylint: disable=too-many-arguments
self,
enable_http=True,
verify=True,
enable_http2=False,
max_connections=None,
max_keepalive_connections=None,
keepalive_expiry=None,
proxies=None,
local_addresses=None,
retries=0,
retry_on_http_error=None,
max_redirects=30 ):
self.enable_http = enable_http
self.verify = verify
self.enable_http2 = enable_http2
self.max_connections = max_connections
self.max_keepalive_connections = max_keepalive_connections
self.keepalive_expiry = keepalive_expiry
self.proxies = proxies
self.local_addresses = local_addresses
self.retries = retries
self.retry_on_http_error = retry_on_http_error
self.max_redirects = max_redirects
self._local_addresses_cycle = self.get_ipaddress_cycle()
self._proxies_cycle = self.get_proxy_cycles()
self._clients = {}
self.check_parameters()
def check_parameters(self):
for address in self.iter_ipaddresses():
if '/' in address:
ipaddress.ip_network(address, False)
else:
ipaddress.ip_address(address)
if self.proxies is not None and not isinstance(self.proxies, (str, dict)):
raise ValueError('proxies type has to be str, dict or None')
def iter_ipaddresses(self):
local_addresses = self.local_addresses
if not local_addresses:
return
if isinstance(local_addresses, str):
local_addresses = [local_addresses]
for address in local_addresses:
yield address
def get_ipaddress_cycle(self):
while True:
count = 0
for address in self.iter_ipaddresses():
if '/' in address:
for a in ipaddress.ip_network(address, False).hosts():
yield str(a)
count += 1
else:
a = ipaddress.ip_address(address)
yield str(a)
count += 1
if count == 0:
yield None
def iter_proxies(self):
if not self.proxies:
return
# https://www.python-httpx.org/compatibility/#proxy-keys
if isinstance(self.proxies, str):
yield 'all://', [self.proxies]
else:
for pattern, proxy_url in self.proxies.items():
pattern = PROXY_PATTERN_MAPPING.get(pattern, pattern)
if isinstance(proxy_url, str):
proxy_url = [proxy_url]
yield pattern, proxy_url
def get_proxy_cycles(self):
proxy_settings = {}
for pattern, proxy_urls in self.iter_proxies():
proxy_settings[pattern] = cycle(proxy_urls)
while True:
# pylint: disable=stop-iteration-return
yield tuple((pattern, next(proxy_url_cycle)) for pattern, proxy_url_cycle in proxy_settings.items())
def get_client(self, verify=None, max_redirects=None):
verify = self.verify if verify is None else verify
max_redirects = self.max_redirects if max_redirects is None else max_redirects
local_address = next(self._local_addresses_cycle)
proxies = next(self._proxies_cycle) # is a tuple so it can be part of the key
key = (verify, max_redirects, local_address, proxies)
if key not in self._clients or self._clients[key].is_closed:
self._clients[key] = new_client(
self.enable_http,
verify,
self.enable_http2,
self.max_connections,
self.max_keepalive_connections,
self.keepalive_expiry,
dict(proxies),
local_address,
0,
max_redirects
)
return self._clients[key]
async def aclose(self):
async def close_client(client):
try:
await client.aclose()
except httpx.HTTPError:
pass
await asyncio.gather(*[close_client(client) for client in self._clients.values()], return_exceptions=False)
@staticmethod
def get_kwargs_clients(kwargs):
kwargs_clients = {}
if 'verify' in kwargs:
kwargs_clients['verify'] = kwargs.pop('verify')
if 'max_redirects' in kwargs:
kwargs_clients['max_redirects'] = kwargs.pop('max_redirects')
return kwargs_clients
def is_valid_respones(self, response):
# pylint: disable=too-many-boolean-expressions
if ((self.retry_on_http_error is True and 400 <= response.status_code <= 599)
or (isinstance(self.retry_on_http_error, list) and response.status_code in self.retry_on_http_error)
or (isinstance(self.retry_on_http_error, int) and response.status_code == self.retry_on_http_error)
):
return False
return True
async def request(self, method, url, **kwargs):
retries = self.retries
while retries >= 0: # pragma: no cover
kwargs_clients = Network.get_kwargs_clients(kwargs)
client = self.get_client(**kwargs_clients)
try:
response = await client.request(method, url, **kwargs)
if self.is_valid_respones(response) or retries <= 0:
return response
except (httpx.RequestError, httpx.HTTPStatusError) as e:
if retries <= 0:
raise e
retries -= 1
def stream(self, method, url, **kwargs):
retries = self.retries
while retries >= 0: # pragma: no cover
kwargs_clients = Network.get_kwargs_clients(kwargs)
client = self.get_client(**kwargs_clients)
try:
response = client.stream(method, url, **kwargs)
if self.is_valid_respones(response) or retries <= 0:
return response
except (httpx.RequestError, httpx.HTTPStatusError) as e:
if retries <= 0:
raise e
retries -= 1
@classmethod
async def aclose_all(cls):
global NETWORKS
await asyncio.gather(*[network.aclose() for network in NETWORKS.values()], return_exceptions=False)
def get_network(name=None):
global NETWORKS
return NETWORKS.get(name or DEFAULT_NAME)
def initialize(settings_engines=None, settings_outgoing=None):
# pylint: disable=import-outside-toplevel)
from searx.engines import engines
from searx import settings
# pylint: enable=import-outside-toplevel)
global NETWORKS
settings_engines = settings_engines or settings['engines']
settings_outgoing = settings_outgoing or settings['outgoing']
# default parameters for AsyncHTTPTransport
# see https://github.com/encode/httpx/blob/e05a5372eb6172287458b37447c30f650047e1b8/httpx/_transports/default.py#L108-L121 # pylint: disable=line-too-long
default_params = {
'enable_http': False,
'verify': True,
'enable_http2': settings_outgoing['enable_http2'],
'max_connections': settings_outgoing['pool_connections'],
'max_keepalive_connections': settings_outgoing['pool_maxsize'],
'keepalive_expiry': settings_outgoing['keepalive_expiry'],
'local_addresses': settings_outgoing['source_ips'],
'proxies': settings_outgoing['proxies'],
'max_redirects': settings_outgoing['max_redirects'],
'retries': settings_outgoing['retries'],
'retry_on_http_error': None,
}
def new_network(params):
nonlocal default_params
result = {}
result.update(default_params)
result.update(params)
return Network(**result)
def iter_networks():
nonlocal settings_engines
for engine_spec in settings_engines:
engine_name = engine_spec['name']
engine = engines.get(engine_name)
if engine is None:
continue
network = getattr(engine, 'network', None)
yield engine_name, engine, network
if NETWORKS:
done()
NETWORKS.clear()
NETWORKS[DEFAULT_NAME] = new_network({})
NETWORKS['ipv4'] = new_network({'local_addresses': '0.0.0.0'})
NETWORKS['ipv6'] = new_network({'local_addresses': '::'})
# define networks from outgoing.networks
for network_name, network in settings_outgoing['networks'].items():
NETWORKS[network_name] = new_network(network)
# define networks from engines.[i].network (except references)
for engine_name, engine, network in iter_networks():
if network is None:
network = {}
for attribute_name, attribute_value in default_params.items():
if hasattr(engine, attribute_name):
network[attribute_name] = getattr(engine, attribute_name)
else:
network[attribute_name] = attribute_value
NETWORKS[engine_name] = new_network(network)
elif isinstance(network, dict):
NETWORKS[engine_name] = new_network(network)
# define networks from engines.[i].network (references)
for engine_name, engine, network in iter_networks():
if isinstance(network, str):
NETWORKS[engine_name] = NETWORKS[network]
# the /image_proxy endpoint has a dedicated network.
# same parameters than the default network, but HTTP/2 is disabled.
# It decreases the CPU load average, and the total time is more or less the same
if 'image_proxy' not in NETWORKS:
image_proxy_params = default_params.copy()
image_proxy_params['enable_http2'] = False
NETWORKS['image_proxy'] = new_network(image_proxy_params)
@atexit.register
def done():
"""Close all HTTP client
Avoid a warning at exit
see https://github.com/encode/httpx/blob/1a6e254f72d9fd5694a1c10a28927e193ab4f76b/httpx/_client.py#L1785
Note: since Network.aclose has to be async, it is not possible to call this method on Network.__del__
So Network.aclose is called here using atexit.register
"""
global NETWORKS
try:
loop = get_loop()
if loop:
future = asyncio.run_coroutine_threadsafe(Network.aclose_all(), loop)
# wait 3 seconds to close the HTTP clients
future.result(3)
finally:
NETWORKS.clear()
NETWORKS[DEFAULT_NAME] = Network()