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Diffstat (limited to 'collectors/python.d.plugin/python_modules/urllib3/poolmanager.py')
| -rw-r--r-- | collectors/python.d.plugin/python_modules/urllib3/poolmanager.py | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/collectors/python.d.plugin/python_modules/urllib3/poolmanager.py b/collectors/python.d.plugin/python_modules/urllib3/poolmanager.py new file mode 100644 index 000000000..adea9bc01 --- /dev/null +++ b/collectors/python.d.plugin/python_modules/urllib3/poolmanager.py @@ -0,0 +1,441 @@ +# SPDX-License-Identifier: MIT +from __future__ import absolute_import +import collections +import functools +import logging + +from ._collections import RecentlyUsedContainer +from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool +from .connectionpool import port_by_scheme +from .exceptions import LocationValueError, MaxRetryError, ProxySchemeUnknown +from .packages.six.moves.urllib.parse import urljoin +from .request import RequestMethods +from .util.url import parse_url +from .util.retry import Retry + + +__all__ = ['PoolManager', 'ProxyManager', 'proxy_from_url'] + + +log = logging.getLogger(__name__) + +SSL_KEYWORDS = ('key_file', 'cert_file', 'cert_reqs', 'ca_certs', + 'ssl_version', 'ca_cert_dir', 'ssl_context') + +# All known keyword arguments that could be provided to the pool manager, its +# pools, or the underlying connections. This is used to construct a pool key. +_key_fields = ( + 'key_scheme', # str + 'key_host', # str + 'key_port', # int + 'key_timeout', # int or float or Timeout + 'key_retries', # int or Retry + 'key_strict', # bool + 'key_block', # bool + 'key_source_address', # str + 'key_key_file', # str + 'key_cert_file', # str + 'key_cert_reqs', # str + 'key_ca_certs', # str + 'key_ssl_version', # str + 'key_ca_cert_dir', # str + 'key_ssl_context', # instance of ssl.SSLContext or urllib3.util.ssl_.SSLContext + 'key_maxsize', # int + 'key_headers', # dict + 'key__proxy', # parsed proxy url + 'key__proxy_headers', # dict + 'key_socket_options', # list of (level (int), optname (int), value (int or str)) tuples + 'key__socks_options', # dict + 'key_assert_hostname', # bool or string + 'key_assert_fingerprint', # str +) + +#: The namedtuple class used to construct keys for the connection pool. +#: All custom key schemes should include the fields in this key at a minimum. +PoolKey = collections.namedtuple('PoolKey', _key_fields) + + +def _default_key_normalizer(key_class, request_context): + """ + 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 + + 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, +} + + +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:: + + >>> manager = PoolManager(num_pools=2) + >>> r = manager.request('GET', 'http://google.com/') + >>> r = manager.request('GET', 'http://google.com/mail') + >>> r = manager.request('GET', 'http://yahoo.com/') + >>> len(manager.pools) + 2 + + """ + + proxy = None + + def __init__(self, num_pools=10, headers=None, **connection_pool_kw): + RequestMethods.__init__(self, headers) + self.connection_pool_kw = connection_pool_kw + self.pools = RecentlyUsedContainer(num_pools, + dispose_func=lambda p: p.close()) + + # 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): + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + self.clear() + # Return False to re-raise any potential exceptions + return False + + def _new_pool(self, scheme, host, port, request_context=None): + """ + Create a new :class:`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 = self.pool_classes_by_scheme[scheme] + if request_context is None: + request_context = self.connection_pool_kw.copy() + + # 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) + + def clear(self): + """ + 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() + + def connection_from_host(self, host, port=None, scheme='http', pool_kwargs=None): + """ + Get a :class:`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) + + def connection_from_context(self, request_context): + """ + Get a :class:`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. + """ + scheme = request_context['scheme'].lower() + pool_key_constructor = self.key_fn_by_scheme[scheme] + pool_key = pool_key_constructor(request_context) + + return self.connection_from_pool_key(pool_key, request_context=request_context) + + def connection_from_pool_key(self, pool_key, request_context=None): + """ + Get a :class:`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 + + def connection_from_url(self, url, pool_kwargs=None): + """ + 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): + """ + 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 urlopen(self, method, url, redirect=True, **kw): + """ + Same as :meth:`urllib3.connectionpool.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) + 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 is not None and u.scheme == "http": + 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) + + try: + retries = retries.increment(method, url, response=response, _pool=conn) + except MaxRetryError: + if retries.raise_on_redirect: + raise + return response + + kw['retries'] = retries + kw['redirect'] = redirect + + log.info("Redirecting %s -> %s", url, redirect_location) + return self.urlopen(method, redirect_location, **kw) + + +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 contaning 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. + + Example: + >>> proxy = urllib3.ProxyManager('http://localhost:3128/') + >>> r1 = proxy.request('GET', 'http://google.com/') + >>> r2 = proxy.request('GET', 'http://httpbin.org/') + >>> len(proxy.pools) + 1 + >>> r3 = proxy.request('GET', 'https://httpbin.org/') + >>> r4 = proxy.request('GET', 'https://twitter.com/') + >>> len(proxy.pools) + 3 + + """ + + def __init__(self, proxy_url, num_pools=10, headers=None, + proxy_headers=None, **connection_pool_kw): + + if isinstance(proxy_url, HTTPConnectionPool): + proxy_url = '%s://%s:%i' % (proxy_url.scheme, proxy_url.host, + proxy_url.port) + proxy = parse_url(proxy_url) + if not proxy.port: + port = port_by_scheme.get(proxy.scheme, 80) + proxy = proxy._replace(port=port) + + if proxy.scheme not in ("http", "https"): + raise ProxySchemeUnknown(proxy.scheme) + + self.proxy = proxy + self.proxy_headers = proxy_headers or {} + + connection_pool_kw['_proxy'] = self.proxy + connection_pool_kw['_proxy_headers'] = self.proxy_headers + + super(ProxyManager, self).__init__( + num_pools, headers, **connection_pool_kw) + + def connection_from_host(self, host, port=None, scheme='http', pool_kwargs=None): + if scheme == "https": + return super(ProxyManager, self).connection_from_host( + host, port, scheme, pool_kwargs=pool_kwargs) + + return super(ProxyManager, self).connection_from_host( + self.proxy.host, self.proxy.port, self.proxy.scheme, pool_kwargs=pool_kwargs) + + def _set_proxy_headers(self, url, headers=None): + """ + 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_ + + def urlopen(self, method, url, redirect=True, **kw): + "Same as HTTP(S)ConnectionPool.urlopen, ``url`` must be absolute." + u = parse_url(url) + + if u.scheme == "http": + # For proxied HTTPS requests, httplib sets the necessary headers + # on the CONNECT to the proxy. For HTTP, 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(ProxyManager, self).urlopen(method, url, redirect=redirect, **kw) + + +def proxy_from_url(url, **kw): + return ProxyManager(proxy_url=url, **kw) |