from __future__ import annotations
import functools
import logging
import typing
import warnings
from types import TracebackType
from urllib.parse import urljoin
from ._collections import RecentlyUsedContainer
from ._request_methods import RequestMethods
from .connection import ProxyConfig
from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool, port_by_scheme
from .exceptions import (
LocationValueError,
MaxRetryError,
ProxySchemeUnknown,
URLSchemeUnknown,
)
from .response import BaseHTTPResponse
from .util.connection import _TYPE_SOCKET_OPTIONS
from .util.proxy import connection_requires_http_tunnel
from .util.retry import Retry
from .util.timeout import Timeout
from .util.url import Url, parse_url
if typing.TYPE_CHECKING:
import ssl
from typing_extensions import Literal
__all__ = ["PoolManager", "ProxyManager", "proxy_from_url"]
log = logging.getLogger(__name__)
SSL_KEYWORDS = (
"key_file",
"cert_file",
"cert_reqs",
"ca_certs",
"ssl_version",
"ssl_minimum_version",
"ssl_maximum_version",
"ca_cert_dir",
"ssl_context",
"key_password",
"server_hostname",
)
# Default value for `blocksize` - a new parameter introduced to
# http.client.HTTPConnection & http.client.HTTPSConnection in Python 3.7
_DEFAULT_BLOCKSIZE = 16384
_SelfT = typing.TypeVar("_SelfT")
class PoolKey(typing.NamedTuple):
"""
All known keyword arguments that could be provided to the pool manager, its
pools, or the underlying connections.
All custom key schemes should include the fields in this key at a minimum.
"""
key_scheme: str
key_host: str
key_port: int | None
key_timeout: Timeout | float | int | None
key_retries: Retry | bool | int | None
key_block: bool | None
key_source_address: tuple[str, int] | None
key_key_file: str | None
key_key_password: str | None
key_cert_file: str | None
key_cert_reqs: str | None
key_ca_certs: str | None
key_ssl_version: int | str | None
key_ssl_minimum_version: ssl.TLSVersion | None
key_ssl_maximum_version: ssl.TLSVersion | None
key_ca_cert_dir: str | None
key_ssl_context: ssl.SSLContext | None
key_maxsize: int | None
key_headers: frozenset[tuple[str, str]] | None
key__proxy: Url | None
key__proxy_headers: frozenset[tuple[str, str]] | None
key__proxy_config: ProxyConfig | None
key_socket_options: _TYPE_SOCKET_OPTIONS | None
key__socks_options: frozenset[tuple[str, str]] | None
key_assert_hostname: bool | str | None
key_assert_fingerprint: str | None
key_server_hostname: str | None
key_blocksize: int | None
def _default_key_normalizer(
key_class: type[PoolKey], request_context: dict[str, typing.Any]
) -> PoolKey:
"""
Create a pool key out of a request context dictionary.
According to RFC 3986, both the scheme and host are case-insensitive.
Therefore, this function normalizes both before constructing the pool
key for an HTTPS request. If you wish to change this behaviour, provide
alternate callables to ``key_fn_by_scheme``.
:param key_class:
The class to use when constructing the key. This should be a namedtuple
with the ``scheme`` and ``host`` keys at a minimum.
:type key_class: namedtuple
:param request_context:
A dictionary-like object that contain the context for a request.
:type request_context: dict
:return: A namedtuple that can be used as a connection pool key.
:rtype: PoolKey
"""
# Since we mutate the dictionary, make a copy first
context = request_context.copy()
context["scheme"] = context["scheme"].lower()
context["host"] = context["host"].lower()
# These are both dictionaries and need to be transformed into frozensets
for key in ("headers", "_proxy_headers", "_socks_options"):
if key in context and context[key] is not None:
context[key] = frozenset(context[key].items())
# The socket_options key may be a list and needs to be transformed into a
# tuple.
socket_opts = context.get("socket_options")
if socket_opts is not None:
context["socket_options"] = tuple(socket_opts)
# Map the kwargs to the names in the namedtuple - this is necessary since
# namedtuples can't have fields starting with '_'.
for key in list(context.keys()):
context["key_" + key] = context.pop(key)
# Default to ``None`` for keys missing from the context
for field in key_class._fields:
if field not in context:
context[field] = None
# Default key_blocksize to _DEFAULT_BLOCKSIZE if missing from the context
if context.get("key_blocksize") is None:
context["key_blocksize"] = _DEFAULT_BLOCKSIZE
return key_class(**context)
#: A dictionary that maps a scheme to a callable that creates a pool key.
#: This can be used to alter the way pool keys are constructed, if desired.
#: Each PoolManager makes a copy of this dictionary so they can be configured
#: globally here, or individually on the instance.
key_fn_by_scheme = {
"http": functools.partial(_default_key_normalizer, PoolKey),
"https": functools.partial(_default_key_normalizer, PoolKey),
}
pool_classes_by_scheme = {"http": HTTPConnectionPool, "https": HTTPSConnectionPool}
[docs]class PoolManager(RequestMethods):
"""
Allows for arbitrary requests while transparently keeping track of
necessary connection pools for you.
:param num_pools:
Number of connection pools to cache before discarding the least
recently used pool.
:param headers:
Headers to include with all requests, unless other headers are given
explicitly.
:param \\**connection_pool_kw:
Additional parameters are used to create fresh
:class:`urllib3.connectionpool.ConnectionPool` instances.
Example:
.. code-block:: python
import urllib3
http = urllib3.PoolManager(num_pools=2)
resp1 = http.request("GET", "https://google.com/")
resp2 = http.request("GET", "https://google.com/mail")
resp3 = http.request("GET", "https://yahoo.com/")
print(len(http.pools))
# 2
"""
proxy: Url | None = None
proxy_config: ProxyConfig | None = None
def __init__(
self,
num_pools: int = 10,
headers: typing.Mapping[str, str] | None = None,
**connection_pool_kw: typing.Any,
) -> None:
super().__init__(headers)
self.connection_pool_kw = connection_pool_kw
self.pools: RecentlyUsedContainer[PoolKey, HTTPConnectionPool]
self.pools = RecentlyUsedContainer(num_pools)
# Locally set the pool classes and keys so other PoolManagers can
# override them.
self.pool_classes_by_scheme = pool_classes_by_scheme
self.key_fn_by_scheme = key_fn_by_scheme.copy()
def __enter__(self: _SelfT) -> _SelfT:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_val: BaseException | None,
exc_tb: TracebackType | None,
) -> Literal[False]:
self.clear()
# Return False to re-raise any potential exceptions
return False
def _new_pool(
self,
scheme: str,
host: str,
port: int,
request_context: dict[str, typing.Any] | None = None,
) -> HTTPConnectionPool:
"""
Create a new :class:`urllib3.connectionpool.ConnectionPool` based on host, port, scheme, and
any additional pool keyword arguments.
If ``request_context`` is provided, it is provided as keyword arguments
to the pool class used. This method is used to actually create the
connection pools handed out by :meth:`connection_from_url` and
companion methods. It is intended to be overridden for customization.
"""
pool_cls: type[HTTPConnectionPool] = self.pool_classes_by_scheme[scheme]
if request_context is None:
request_context = self.connection_pool_kw.copy()
# Default blocksize to _DEFAULT_BLOCKSIZE if missing or explicitly
# set to 'None' in the request_context.
if request_context.get("blocksize") is None:
request_context["blocksize"] = _DEFAULT_BLOCKSIZE
# Although the context has everything necessary to create the pool,
# this function has historically only used the scheme, host, and port
# in the positional args. When an API change is acceptable these can
# be removed.
for key in ("scheme", "host", "port"):
request_context.pop(key, None)
if scheme == "http":
for kw in SSL_KEYWORDS:
request_context.pop(kw, None)
return pool_cls(host, port, **request_context)
[docs] def clear(self) -> None:
"""
Empty our store of pools and direct them all to close.
This will not affect in-flight connections, but they will not be
re-used after completion.
"""
self.pools.clear()
[docs] def connection_from_host(
self,
host: str | None,
port: int | None = None,
scheme: str | None = "http",
pool_kwargs: dict[str, typing.Any] | None = None,
) -> HTTPConnectionPool:
"""
Get a :class:`urllib3.connectionpool.ConnectionPool` based on the host, port, and scheme.
If ``port`` isn't given, it will be derived from the ``scheme`` using
``urllib3.connectionpool.port_by_scheme``. If ``pool_kwargs`` is
provided, it is merged with the instance's ``connection_pool_kw``
variable and used to create the new connection pool, if one is
needed.
"""
if not host:
raise LocationValueError("No host specified.")
request_context = self._merge_pool_kwargs(pool_kwargs)
request_context["scheme"] = scheme or "http"
if not port:
port = port_by_scheme.get(request_context["scheme"].lower(), 80)
request_context["port"] = port
request_context["host"] = host
return self.connection_from_context(request_context)
[docs] def connection_from_context(
self, request_context: dict[str, typing.Any]
) -> HTTPConnectionPool:
"""
Get a :class:`urllib3.connectionpool.ConnectionPool` based on the request context.
``request_context`` must at least contain the ``scheme`` key and its
value must be a key in ``key_fn_by_scheme`` instance variable.
"""
if "strict" in request_context:
warnings.warn(
"The 'strict' parameter is no longer needed on Python 3+. "
"This will raise an error in urllib3 v2.1.0.",
DeprecationWarning,
)
request_context.pop("strict")
scheme = request_context["scheme"].lower()
pool_key_constructor = self.key_fn_by_scheme.get(scheme)
if not pool_key_constructor:
raise URLSchemeUnknown(scheme)
pool_key = pool_key_constructor(request_context)
return self.connection_from_pool_key(pool_key, request_context=request_context)
[docs] def connection_from_pool_key(
self, pool_key: PoolKey, request_context: dict[str, typing.Any]
) -> HTTPConnectionPool:
"""
Get a :class:`urllib3.connectionpool.ConnectionPool` based on the provided pool key.
``pool_key`` should be a namedtuple that only contains immutable
objects. At a minimum it must have the ``scheme``, ``host``, and
``port`` fields.
"""
with self.pools.lock:
# If the scheme, host, or port doesn't match existing open
# connections, open a new ConnectionPool.
pool = self.pools.get(pool_key)
if pool:
return pool
# Make a fresh ConnectionPool of the desired type
scheme = request_context["scheme"]
host = request_context["host"]
port = request_context["port"]
pool = self._new_pool(scheme, host, port, request_context=request_context)
self.pools[pool_key] = pool
return pool
[docs] def connection_from_url(
self, url: str, pool_kwargs: dict[str, typing.Any] | None = None
) -> HTTPConnectionPool:
"""
Similar to :func:`urllib3.connectionpool.connection_from_url`.
If ``pool_kwargs`` is not provided and a new pool needs to be
constructed, ``self.connection_pool_kw`` is used to initialize
the :class:`urllib3.connectionpool.ConnectionPool`. If ``pool_kwargs``
is provided, it is used instead. Note that if a new pool does not
need to be created for the request, the provided ``pool_kwargs`` are
not used.
"""
u = parse_url(url)
return self.connection_from_host(
u.host, port=u.port, scheme=u.scheme, pool_kwargs=pool_kwargs
)
def _merge_pool_kwargs(
self, override: dict[str, typing.Any] | None
) -> dict[str, typing.Any]:
"""
Merge a dictionary of override values for self.connection_pool_kw.
This does not modify self.connection_pool_kw and returns a new dict.
Any keys in the override dictionary with a value of ``None`` are
removed from the merged dictionary.
"""
base_pool_kwargs = self.connection_pool_kw.copy()
if override:
for key, value in override.items():
if value is None:
try:
del base_pool_kwargs[key]
except KeyError:
pass
else:
base_pool_kwargs[key] = value
return base_pool_kwargs
def _proxy_requires_url_absolute_form(self, parsed_url: Url) -> bool:
"""
Indicates if the proxy requires the complete destination URL in the
request. Normally this is only needed when not using an HTTP CONNECT
tunnel.
"""
if self.proxy is None:
return False
return not connection_requires_http_tunnel(
self.proxy, self.proxy_config, parsed_url.scheme
)
[docs] def urlopen( # type: ignore[override]
self, method: str, url: str, redirect: bool = True, **kw: typing.Any
) -> BaseHTTPResponse:
"""
Same as :meth:`urllib3.HTTPConnectionPool.urlopen`
with custom cross-host redirect logic and only sends the request-uri
portion of the ``url``.
The given ``url`` parameter must be absolute, such that an appropriate
:class:`urllib3.connectionpool.ConnectionPool` can be chosen for it.
"""
u = parse_url(url)
if u.scheme is None:
warnings.warn(
"URLs without a scheme (ie 'https://') are deprecated and will raise an error "
"in a future version of urllib3. To avoid this DeprecationWarning ensure all URLs "
"start with 'https://' or 'http://'. Read more in this issue: "
"https://github.com/urllib3/urllib3/issues/2920",
category=DeprecationWarning,
stacklevel=2,
)
conn = self.connection_from_host(u.host, port=u.port, scheme=u.scheme)
kw["assert_same_host"] = False
kw["redirect"] = False
if "headers" not in kw:
kw["headers"] = self.headers
if self._proxy_requires_url_absolute_form(u):
response = conn.urlopen(method, url, **kw)
else:
response = conn.urlopen(method, u.request_uri, **kw)
redirect_location = redirect and response.get_redirect_location()
if not redirect_location:
return response
# Support relative URLs for redirecting.
redirect_location = urljoin(url, redirect_location)
# RFC 7231, Section 6.4.4
if response.status == 303:
method = "GET"
retries = kw.get("retries")
if not isinstance(retries, Retry):
retries = Retry.from_int(retries, redirect=redirect)
# Strip headers marked as unsafe to forward to the redirected location.
# Check remove_headers_on_redirect to avoid a potential network call within
# conn.is_same_host() which may use socket.gethostbyname() in the future.
if retries.remove_headers_on_redirect and not conn.is_same_host(
redirect_location
):
new_headers = kw["headers"].copy()
for header in kw["headers"]:
if header.lower() in retries.remove_headers_on_redirect:
new_headers.pop(header, None)
kw["headers"] = new_headers
try:
retries = retries.increment(method, url, response=response, _pool=conn)
except MaxRetryError:
if retries.raise_on_redirect:
response.drain_conn()
raise
return response
kw["retries"] = retries
kw["redirect"] = redirect
log.info("Redirecting %s -> %s", url, redirect_location)
response.drain_conn()
return self.urlopen(method, redirect_location, **kw)
[docs]class ProxyManager(PoolManager):
"""
Behaves just like :class:`PoolManager`, but sends all requests through
the defined proxy, using the CONNECT method for HTTPS URLs.
:param proxy_url:
The URL of the proxy to be used.
:param proxy_headers:
A dictionary containing headers that will be sent to the proxy. In case
of HTTP they are being sent with each request, while in the
HTTPS/CONNECT case they are sent only once. Could be used for proxy
authentication.
:param proxy_ssl_context:
The proxy SSL context is used to establish the TLS connection to the
proxy when using HTTPS proxies.
:param use_forwarding_for_https:
(Defaults to False) If set to True will forward requests to the HTTPS
proxy to be made on behalf of the client instead of creating a TLS
tunnel via the CONNECT method. **Enabling this flag means that request
and response headers and content will be visible from the HTTPS proxy**
whereas tunneling keeps request and response headers and content
private. IP address, target hostname, SNI, and port are always visible
to an HTTPS proxy even when this flag is disabled.
:param proxy_assert_hostname:
The hostname of the certificate to verify against.
:param proxy_assert_fingerprint:
The fingerprint of the certificate to verify against.
Example:
.. code-block:: python
import urllib3
proxy = urllib3.ProxyManager("https://localhost:3128/")
resp1 = proxy.request("GET", "https://google.com/")
resp2 = proxy.request("GET", "https://httpbin.org/")
print(len(proxy.pools))
# 1
resp3 = proxy.request("GET", "https://httpbin.org/")
resp4 = proxy.request("GET", "https://twitter.com/")
print(len(proxy.pools))
# 3
"""
def __init__(
self,
proxy_url: str,
num_pools: int = 10,
headers: typing.Mapping[str, str] | None = None,
proxy_headers: typing.Mapping[str, str] | None = None,
proxy_ssl_context: ssl.SSLContext | None = None,
use_forwarding_for_https: bool = False,
proxy_assert_hostname: None | str | Literal[False] = None,
proxy_assert_fingerprint: str | None = None,
**connection_pool_kw: typing.Any,
) -> None:
if isinstance(proxy_url, HTTPConnectionPool):
str_proxy_url = f"{proxy_url.scheme}://{proxy_url.host}:{proxy_url.port}"
else:
str_proxy_url = proxy_url
proxy = parse_url(str_proxy_url)
if proxy.scheme not in ("http", "https"):
raise ProxySchemeUnknown(proxy.scheme)
if not proxy.port:
port = port_by_scheme.get(proxy.scheme, 80)
proxy = proxy._replace(port=port)
self.proxy = proxy
self.proxy_headers = proxy_headers or {}
self.proxy_ssl_context = proxy_ssl_context
self.proxy_config = ProxyConfig(
proxy_ssl_context,
use_forwarding_for_https,
proxy_assert_hostname,
proxy_assert_fingerprint,
)
connection_pool_kw["_proxy"] = self.proxy
connection_pool_kw["_proxy_headers"] = self.proxy_headers
connection_pool_kw["_proxy_config"] = self.proxy_config
super().__init__(num_pools, headers, **connection_pool_kw)
[docs] def connection_from_host(
self,
host: str | None,
port: int | None = None,
scheme: str | None = "http",
pool_kwargs: dict[str, typing.Any] | None = None,
) -> HTTPConnectionPool:
if scheme == "https":
return super().connection_from_host(
host, port, scheme, pool_kwargs=pool_kwargs
)
return super().connection_from_host(
self.proxy.host, self.proxy.port, self.proxy.scheme, pool_kwargs=pool_kwargs # type: ignore[union-attr]
)
def _set_proxy_headers(
self, url: str, headers: typing.Mapping[str, str] | None = None
) -> typing.Mapping[str, str]:
"""
Sets headers needed by proxies: specifically, the Accept and Host
headers. Only sets headers not provided by the user.
"""
headers_ = {"Accept": "*/*"}
netloc = parse_url(url).netloc
if netloc:
headers_["Host"] = netloc
if headers:
headers_.update(headers)
return headers_
[docs] def urlopen( # type: ignore[override]
self, method: str, url: str, redirect: bool = True, **kw: typing.Any
) -> BaseHTTPResponse:
"Same as HTTP(S)ConnectionPool.urlopen, ``url`` must be absolute."
u = parse_url(url)
if not connection_requires_http_tunnel(self.proxy, self.proxy_config, u.scheme):
# For connections using HTTP CONNECT, httplib sets the necessary
# headers on the CONNECT to the proxy. If we're not using CONNECT,
# we'll definitely need to set 'Host' at the very least.
headers = kw.get("headers", self.headers)
kw["headers"] = self._set_proxy_headers(url, headers)
return super().urlopen(method, url, redirect=redirect, **kw)
[docs]def proxy_from_url(url: str, **kw: typing.Any) -> ProxyManager:
return ProxyManager(proxy_url=url, **kw)