session.py

"""
Copyright 2019 Goldman Sachs.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on ans
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
"""
import asyncio
import inspect
import itertools
import json
import logging
import os
import ssl
from abc import abstractmethod
from configparser import ConfigParser
from enum import Enum, auto, unique
from typing import Optional, Union, Iterable, Tuple

import backoff
import certifi
import msgpack
import pandas as pd
import requests
import requests.adapters
import requests.cookies
import urllib3
from opentracing import Format
from opentracing.tags import HTTP_URL, HTTP_METHOD, HTTP_STATUS_CODE

from gs_quant import version as APP_VERSION
from gs_quant.base import Base
from gs_quant.context_base import ContextBase, nullcontext
from gs_quant.errors import MqError, MqRequestError, MqAuthenticationError, MqUninitialisedError
from gs_quant.json_encoder import JSONEncoder, encode_default
from gs_quant.tracing import Tracer

logger = logging.getLogger(__name__)

API_VERSION = 'v1'
DEFAULT_APPLICATION = 'gs-quant'
DEFAULT_TIMEOUT = 65


@unique
class Environment(Enum):
    DEV = auto()
    QA = auto()
    PROD = auto()


class CustomHttpAdapter(requests.adapters.HTTPAdapter):
    # "Transport adapter" that allows us to use custom ssl_context.

    def __init__(self, ssl_context=None, **kwargs):
        self.ssl_context = ssl_context
        super().__init__(**kwargs)

    def init_poolmanager(self, connections, maxsize=100, block=False):
        self.poolmanager = urllib3.poolmanager.PoolManager(num_pools=connections, maxsize=maxsize, block=block,
                                                           ssl_context=self.ssl_context)


class Domain:
    MDS_US_EAST = "MdsDomainEast"
    MDS_WEB = "MdsWebDomain"
    APP = "AppDomain"


class GsSession(ContextBase):
    __config = None
    __ssl_ctx = None

    class Scopes(Enum):
        READ_CONTENT = 'read_content'
        READ_FINANCIAL_DATA = 'read_financial_data'
        READ_PRODUCT_DATA = 'read_product_data'
        READ_USER_PROFILE = 'read_user_profile'
        MODIFY_CONTENT = 'modify_content'
        MODIFY_FINANCIAL_DATA = 'modify_financial_data'
        MODIFY_PRODUCT_DATA = 'modify_product_data'
        MODIFY_USER_PROFILE = 'modify_user_profile'
        RUN_ANALYTICS = 'run_analytics'
        EXECUTE_TRADES = 'execute_trades'

        @classmethod
        def get_default(cls):
            return (
                cls.READ_CONTENT.value,
                cls.READ_PRODUCT_DATA.value,
                cls.READ_FINANCIAL_DATA.value,
                cls.READ_USER_PROFILE.value
            )

    def __init__(self, domain: str, environment: str = None, api_version: str = API_VERSION,
                 application: str = DEFAULT_APPLICATION, verify=True,
                 http_adapter: requests.adapters.HTTPAdapter = None, application_version=APP_VERSION, proxies=None):
        super().__init__()
        self._session = None
        self._session_async = None
        self.domain = domain
        if environment in tuple(x.name for x in Environment):
            self.environment = Environment[environment]
        elif isinstance(domain, Environment):
            self.environment = domain
        else:
            self.environment = Environment.DEV
        self.api_version = api_version
        self.application = application
        self.verify = verify
        if http_adapter is None:
            if ssl.OPENSSL_VERSION_INFO >= (3, 0, 0):
                self.http_adapter = CustomHttpAdapter(self.__ssl_context())
            else:
                self.http_adapter = requests.adapters.HTTPAdapter(pool_maxsize=100)
        else:
            self.http_adapter = http_adapter
        self.application_version = application_version
        self.proxies = proxies

    @backoff.on_exception(lambda: backoff.expo(factor=2),
                          (requests.exceptions.HTTPError, requests.exceptions.Timeout),
                          max_tries=5)
    @backoff.on_predicate(lambda: backoff.expo(factor=2),
                          lambda x: x.status_code in (500, 502, 503, 504),
                          max_tries=5)
    @abstractmethod
    def _authenticate(self):
        raise NotImplementedError("Must implement _authenticate")

    def _authenticate_async(self):
        if self._has_async_session():
            self._session_async.headers.update([(k, v) for k, v in self._session.headers.items()])
            for cookie in self._session.cookies:
                self._session_async.cookies.set(cookie.name, cookie.value, domain=cookie.domain)

    def _authenticate_all_sessions(self):
        self._authenticate()
        self._authenticate_async()

    def _on_enter(self):
        self.__close_on_exit = self._session is None
        if not self._session:
            self.init()

    def _on_exit(self, exc_type, exc_val, exc_tb):
        if self.__close_on_exit:
            self._session = None
            self._session_async = None

    def _has_async_session(self) -> bool:
        return self._session_async and not self._session_async.is_closed

    def _init_async(self):
        import httpx
        if not self._has_async_session():
            self._session_async = httpx.AsyncClient(follow_redirects=True, verify=self.verify, proxies=self.proxies)
            self._session_async.headers.update({'X-Application': self.application})
            self._session_async.headers.update({'X-Version': self.application_version})
            self._authenticate_async()

    async def _on_aenter(self):
        self.__close_on_exit = self._session is None
        if not self._has_async_session():
            self.init()
            self._init_async()

    async def _on_aexit(self, exc_type, exc_val, exc_tb):
        if self.__close_on_exit:
            self._session = None
            self._session_async = None

    def init(self):
        if not self._session:
            self._session = requests.Session()
            if self.http_adapter is not None:
                self._session.mount('https://', self.http_adapter)
            if self.proxies is not None:
                self._session.proxies = self.proxies
            self._session.verify = self.verify
            self._session.headers.update({'X-Application': self.application})
            self._session.headers.update({'X-Version': self.application_version})
            self._authenticate()

    def close(self):
        self._session: requests.Session
        if self._session:
            # don't close a shared adapter
            if self.http_adapter is None:
                self._session.close()
            self._session = None
        if self._session_async:
            try:
                asyncio.run(self._close_async())
            except Exception:
                pass

    async def _close_async(self):
        if self._session_async:
            await self._session_async.aclose()
            self._session_async = None

    def __del__(self):
        self.close()

    @staticmethod
    def __ssl_context() -> ssl.SSLContext:
        if GsSession.__ssl_ctx is None:
            GsSession.__ssl_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
            GsSession.__ssl_ctx.check_hostname = False
            GsSession.__ssl_ctx.verify_mode = 0
            GsSession.__ssl_ctx.options |= 0x4  # OP_LEGACY_SERVER_CONNECT
            GsSession.__ssl_ctx.load_default_certs()
            GsSession.__ssl_ctx.load_verify_locations(certifi.where())

        return GsSession.__ssl_ctx

    @staticmethod
    def __unpack(results: Union[dict, list], cls: type) -> Union[Base, tuple, dict]:
        if issubclass(cls, Base):
            if isinstance(results, list):
                return tuple(None if r is None else cls.from_dict(r) for r in results)
            else:
                return None if results is None else cls.from_dict(results)
        else:
            if isinstance(results, list):
                return tuple(cls(**r) for r in results)
            else:
                return cls(**results)

    def _build_url(self, domain: Optional[str], path: str, include_version: Optional[bool]):
        if not domain:
            domain = self.domain
        url = '{}{}{}'.format(domain, '/' + self.api_version if include_version else '', path)
        return url

    def _build_request_params(
            self,
            method: str,
            path: str,
            url: str,
            payload: Optional[Union[dict, str, bytes, Base, pd.DataFrame]],
            request_headers: Optional[dict],
            timeout: Optional[int],
            use_body: bool,
            data_key: str,
            tracing_scope: Optional[dict]
    ) -> Tuple[dict, str]:
        is_dataframe = isinstance(payload, pd.DataFrame)
        if not is_dataframe:
            payload = payload or {}
        kwargs = {
            'timeout': timeout
        }

        if tracing_scope:
            tracing_scope.span.set_tag('path', path)
            tracing_scope.span.set_tag('timeout', timeout)
            tracing_scope.span.set_tag(HTTP_URL, url)
            tracing_scope.span.set_tag(HTTP_METHOD, method)
            tracing_scope.span.set_tag('span.kind', 'client')

        if method in ['GET', 'DELETE'] and not use_body:
            kwargs['params'] = payload
            if tracing_scope:
                headers = self._session.headers.copy()
                Tracer.inject(Format.HTTP_HEADERS, headers)
                kwargs['headers'] = headers
        elif method in ['POST', 'PUT'] or (method in ['GET', 'DELETE'] and use_body):
            headers = self._session.headers.copy()

            if request_headers:
                headers.update(request_headers)

            if tracing_scope:
                Tracer.inject(Format.HTTP_HEADERS, headers)

            if 'Content-Type' not in headers:
                headers.update({'Content-Type': 'application/json; charset=utf-8'})

            use_msgpack = headers.get('Content-Type') == 'application/x-msgpack'
            kwargs['headers'] = headers

            if is_dataframe or payload:
                kwargs[data_key] = (payload if isinstance(payload, (str, bytes)) else
                                    msgpack.dumps(payload, default=encode_default) if use_msgpack else
                                    json.dumps(payload, cls=JSONEncoder))
        else:
            raise MqError('not implemented')
        return kwargs

    def _parse_response(self, request_id, response, method: str, url: str,
                        cls: Optional[type], return_request_id: Optional[bool]):
        if not 199 < response.status_code < 300:
            reason = response.reason if hasattr(response, 'reason') else response.reason_phrase
            raise MqRequestError(response.status_code, f'{reason}: {response.text}',
                                 context=f'{request_id}: {method} {url}')
        elif 'Content-Type' in response.headers:
            if 'application/x-msgpack' in response.headers['Content-Type']:
                ret = msgpack.unpackb(response.content, raw=False)
            elif 'application/json' in response.headers['Content-Type']:
                ret = json.loads(response.text)
            else:
                ret = {'raw': response}
            if cls and ret:
                if isinstance(ret, dict) and 'results' in ret:
                    ret['results'] = self.__unpack(ret['results'], cls)
                else:
                    ret = self.__unpack(ret, cls)
            return (ret, request_id) if return_request_id else ret
        else:
            ret = {'raw': response}
            if return_request_id:
                ret['request_id'] = request_id
            return ret

    def __request(
            self,
            method: str,
            path: str,
            payload: Optional[Union[dict, str, bytes, Base, pd.DataFrame]] = None,
            request_headers: Optional[dict] = None,
            cls: Optional[type] = None,
            try_auth: Optional[bool] = True,
            include_version: Optional[bool] = True,
            timeout: Optional[int] = DEFAULT_TIMEOUT,
            return_request_id: Optional[bool] = False,
            use_body: bool = False,
            domain: Optional[str] = None
    ) -> Union[Base, tuple, dict]:
        span = Tracer.get_instance().active_span
        url = self._build_url(domain, path, include_version)
        tracer = Tracer(url) if span else nullcontext()
        with tracer as scope:
            kwargs = self._build_request_params(method, path, url, payload, request_headers, timeout, use_body, "data",
                                                scope)
            response = self._session.request(method, url, **kwargs)
            request_id = response.headers.get('x-dash-requestid')
            logger.debug('Handling response for [Request ID]: %s [Method]: %s [URL]: %s', request_id, method, url)
            if scope:
                scope.span.set_tag(HTTP_STATUS_CODE, response.status_code)
                scope.span.set_tag('dash.request.id', request_id)
        if response.status_code == 401:
            # Expired token or other authorization issue
            if not try_auth:
                raise MqRequestError(response.status_code, response.text, context=f'{request_id}: {method} {url}')
            self._authenticate()
            return self.__request(method, path, payload=payload, request_headers=request_headers, cls=cls,
                                  try_auth=False, include_version=include_version, timeout=timeout,
                                  return_request_id=return_request_id, use_body=use_body, domain=domain)
        return self._parse_response(request_id, response, method, url, cls, return_request_id)

    async def __request_async(
            self,
            method: str,
            path: str,
            payload: Optional[Union[dict, str, bytes, Base, pd.DataFrame]] = None,
            request_headers: Optional[dict] = None,
            cls: Optional[type] = None,
            try_auth: Optional[bool] = True,
            include_version: Optional[bool] = True,
            timeout: Optional[int] = DEFAULT_TIMEOUT,
            return_request_id: Optional[bool] = False,
            use_body: bool = False,
            domain: Optional[str] = None
    ) -> Union[Base, tuple, dict]:
        self._init_async()
        span = Tracer.get_instance().active_span
        url = self._build_url(domain, path, include_version)
        tracer = Tracer(f'http:/{path}') if span else nullcontext()
        with tracer as scope:
            kwargs = self._build_request_params(method, path, url, payload, request_headers, timeout, use_body,
                                                "content", scope)
            response = await self._session_async.request(method, url, **kwargs)
            request_id = response.headers.get('x-dash-requestid')
            if scope:
                scope.span.set_tag(HTTP_STATUS_CODE, response.status_code)
                scope.span.set_tag('dash.request.id', request_id)

        logger.debug('Handling response for [Request ID]: %s [Method]: %s [URL]: %s', request_id, method, url)
        if response.status_code == 401:
            # Expired token or other authorization issue
            if not try_auth:
                raise MqRequestError(response.status_code, response.text, context=f'{request_id}: {method} {url}')
            self._authenticate_all_sessions()
            res = await self.__request_async(method, path, payload=payload, request_headers=request_headers,
                                             cls=cls, try_auth=False, include_version=include_version, timeout=timeout,
                                             return_request_id=return_request_id, use_body=use_body, domain=domain)
            return res
        return self._parse_response(request_id, response, method, url, cls, return_request_id)

    def _get(self, path: str, payload: Optional[Union[dict, Base]] = None, request_headers: Optional[dict] = None,
             cls: Optional[type] = None, include_version: Optional[bool] = True,
             timeout: Optional[int] = DEFAULT_TIMEOUT, return_request_id: Optional[bool] = False,
             domain: Optional[str] = None) -> Union[Base, tuple, dict]:
        return self.__request('GET', path, payload=payload, request_headers=request_headers, cls=cls,
                              include_version=include_version, timeout=timeout, return_request_id=return_request_id,
                              domain=domain)

    async def _get_async(self, path: str, payload: Optional[Union[dict, Base]] = None,
                         request_headers: Optional[dict] = None, cls: Optional[type] = None,
                         include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
                         return_request_id: Optional[bool] = False, domain: Optional[str] = None) \
            -> Union[Base, tuple, dict]:
        ret = await self.__request_async('GET', path, payload=payload, request_headers=request_headers, cls=cls,
                                         include_version=include_version, timeout=timeout,
                                         return_request_id=return_request_id, domain=domain)
        return ret

    def _post(self, path: str, payload: Optional[Union[dict, bytes, Base, pd.DataFrame]] = None,
              request_headers: Optional[dict] = None, cls: Optional[type] = None,
              include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
              return_request_id: Optional[bool] = False, domain: Optional[str] = None) -> Union[Base, tuple, dict]:
        return self.__request('POST', path, payload=payload, request_headers=request_headers, cls=cls,
                              include_version=include_version, timeout=timeout, return_request_id=return_request_id,
                              domain=domain)

    async def _post_async(self, path: str, payload: Optional[Union[dict, bytes, Base, pd.DataFrame]] = None,
                          request_headers: Optional[dict] = None, cls: Optional[type] = None,
                          include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
                          return_request_id: Optional[bool] = False,
                          domain: Optional[str] = None) -> Union[Base, tuple, dict]:
        ret = await self.__request_async('POST', path, payload=payload, request_headers=request_headers, cls=cls,
                                         include_version=include_version, timeout=timeout,
                                         return_request_id=return_request_id, domain=domain)
        return ret

    def _delete(self, path: str, payload: Optional[Union[dict, Base]] = None,
                request_headers: Optional[dict] = None, cls: Optional[type] = None,
                include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
                return_request_id: Optional[bool] = False, use_body: Optional[bool] = False) \
            -> Union[Base, tuple, dict]:
        return self.__request('DELETE', path, payload=payload, request_headers=request_headers, cls=cls,
                              include_version=include_version, timeout=timeout, return_request_id=return_request_id,
                              use_body=use_body)

    async def _delete_async(self, path: str, payload: Optional[Union[dict, Base]] = None,
                            request_headers: Optional[dict] = None, cls: Optional[type] = None,
                            include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
                            return_request_id: Optional[bool] = False, use_body: Optional[bool] = False) \
            -> Union[Base, tuple, dict]:
        ret = await self.__request_async('DELETE', path, payload=payload, request_headers=request_headers, cls=cls,
                                         include_version=include_version, timeout=timeout,
                                         return_request_id=return_request_id, use_body=use_body)
        return ret

    def _put(self, path: str, payload: Optional[Union[dict, Base]] = None,
             request_headers: Optional[dict] = None, cls: Optional[type] = None, include_version: Optional[bool] = True,
             timeout: Optional[int] = DEFAULT_TIMEOUT, return_request_id: Optional[bool] = False) \
            -> Union[Base, tuple, dict]:
        return self.__request('PUT', path, payload=payload, request_headers=request_headers, cls=cls,
                              include_version=include_version, timeout=timeout, return_request_id=return_request_id)

    async def _put_async(self, path: str, payload: Optional[Union[dict, Base]] = None,
                         request_headers: Optional[dict] = None, cls: Optional[type] = None,
                         include_version: Optional[bool] = True, timeout: Optional[int] = DEFAULT_TIMEOUT,
                         return_request_id: Optional[bool] = False) -> Union[Base, tuple, dict]:
        ret = await self.__request_async('PUT', path, payload=payload, request_headers=request_headers, cls=cls,
                                         include_version=include_version, timeout=timeout,
                                         return_request_id=return_request_id)
        return ret

    def _connect_websocket(self, path: str, headers: Optional[dict] = None):
        import websockets
        url = 'ws{}{}{}'.format(self.domain[4:], '/' + self.api_version, path)
        extra_headers = self._headers() + list((headers or {}).items())
        return websockets.connect(url,
                                  extra_headers=extra_headers,
                                  max_size=2 ** 32,
                                  read_limit=2 ** 32,
                                  ssl=self.__ssl_context() if url.startswith('wss') else None)

    def _headers(self):
        return [('Cookie', 'GSSSO=' + self._session.cookies['GSSSO'])]

    @classmethod
    def _config_for_environment(cls, environment):
        if cls.__config is None:
            cls.__config = ConfigParser()
            cls.__config.read(os.path.join(os.path.dirname(inspect.getfile(cls)), 'config.ini'))

        return cls.__config[environment]

    @classmethod
    def use(
            cls,
            environment_or_domain: Union[Environment, str] = Environment.PROD,
            client_id: Optional[str] = None,
            client_secret: Optional[str] = None,
            scopes: Optional[Union[Iterable[Union[Scopes, str]], str]] = (),
            api_version: str = API_VERSION,
            application: str = DEFAULT_APPLICATION,
            http_adapter: requests.adapters.HTTPAdapter = None,
            use_mds: bool = False,
            domain: Domain = Domain.APP
    ) -> None:
        environment_or_domain = environment_or_domain.name if isinstance(environment_or_domain,
                                                                         Environment) else environment_or_domain
        if domain is None:
            raise MqError("None is not a valid domain.")
        domain = Domain.MDS_US_EAST if use_mds else domain
        session = cls.get(
            environment_or_domain,
            client_id=client_id,
            client_secret=client_secret,
            scopes=scopes,
            api_version=api_version,
            application=application,
            http_adapter=http_adapter,
            domain=domain
        )

        session.init()
        cls.current = session

    @classmethod
    def get(
            cls,
            environment_or_domain: Union[Environment, str] = Environment.PROD,
            client_id: Optional[str] = None,
            client_secret: Optional[str] = None,
            scopes: Optional[Union[Iterable[Union[Scopes, str]], str]] = (),
            token: str = '',
            is_gssso: bool = False,
            api_version: str = API_VERSION,
            application: str = DEFAULT_APPLICATION,
            http_adapter: requests.adapters.HTTPAdapter = None,
            application_version: str = APP_VERSION,
            domain: Domain = Domain.APP
    ) -> 'GsSession':
        """ Return an instance of the appropriate session type for the given credentials"""

        environment_or_domain = environment_or_domain.name if isinstance(environment_or_domain,
                                                                         Environment) else environment_or_domain

        if client_id is not None:
            if isinstance(scopes, str):
                scopes = (scopes,)

            scopes = (scope if isinstance(scope, str) else scope.value for scope in scopes)
            scopes = tuple(set(itertools.chain(scopes, cls.Scopes.get_default())))

            return OAuth2Session(environment_or_domain, client_id, client_secret, scopes, api_version=api_version,
                                 application=application, http_adapter=http_adapter, domain=domain)
        elif token:
            if is_gssso:
                try:
                    return PassThroughGSSSOSession(environment_or_domain, token, api_version=api_version,
                                                   application=application, http_adapter=http_adapter)
                except NameError:
                    raise MqUninitialisedError('This option requires gs_quant_auth to be installed')
            else:
                return PassThroughSession(environment_or_domain, token, api_version=api_version,
                                          application=application, http_adapter=http_adapter)
        else:
            if domain == Domain.MDS_WEB:
                try:
                    return MQLoginSession(environment_or_domain, api_version=api_version, http_adapter=http_adapter,
                                          application_version=application_version, application=application)
                except NameError:
                    raise MqUninitialisedError('Unable to obtain MarqueeLogin token. '
                                               'Please use client_id and client_secret to make the query')
            else:
                try:
                    return KerberosSession(environment_or_domain, api_version=api_version, http_adapter=http_adapter,
                                           application_version=application_version, application=application)
                except NameError:
                    raise MqUninitialisedError('Must specify client_id and client_secret')

    def is_internal(self) -> bool:
        return False


class OAuth2Session(GsSession):

    def __init__(self, environment, client_id, client_secret, scopes, api_version=API_VERSION,
                 application=DEFAULT_APPLICATION, http_adapter=None, domain=Domain.APP):

        if environment not in (Environment.PROD.name, Environment.QA.name, Environment.DEV.name):
            env_config = self._config_for_environment(Environment.DEV.name)
            url = environment
        else:
            env_config = self._config_for_environment(environment)
            url = env_config[domain]

        super().__init__(url, environment, api_version=api_version, application=application, http_adapter=http_adapter)
        self.auth_url = env_config['AuthURL']
        self.client_id = client_id
        self.client_secret = client_secret
        self.scopes = scopes

        if environment == Environment.DEV.name or (url != env_config['AppDomain'] and not domain == Domain.MDS_US_EAST):
            import urllib3
            urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
            self.verify = False

    def _authenticate(self):
        auth_data = {
            'grant_type': 'client_credentials',
            'client_id': self.client_id,
            'client_secret': self.client_secret,
            'scope': ' '.join(self.scopes)
        }
        reply = self._session.post(self.auth_url, data=auth_data, verify=self.verify)
        if reply.status_code != 200:
            raise MqAuthenticationError(reply.status_code, reply.text, context=self.auth_url)

        response = json.loads(reply.text)
        self._session.headers.update({'Authorization': 'Bearer {}'.format(response['access_token'])})

    def _headers(self):
        return [('Authorization', self._session.headers['Authorization'])]


class PassThroughSession(GsSession):

    def __init__(self, environment: str, token, api_version=API_VERSION,
                 application=DEFAULT_APPLICATION, http_adapter=None):
        domain = self._config_for_environment(environment)['AppDomain']
        verify = True

        super().__init__(domain, environment, api_version=api_version, application=application, verify=verify,
                         http_adapter=http_adapter)

        self.token = token

    def _authenticate(self):
        self._session.headers.update({'Authorization': 'Bearer {}'.format(self.token)})

    def _headers(self):
        return [('Authorization', self._session.headers['Authorization'])]


try:
    from gs_quant_auth.kerberos.session_kerberos import KerberosSessionMixin

    class KerberosSession(KerberosSessionMixin, GsSession):

        def __init__(self, environment_or_domain: str, api_version: str = API_VERSION,
                     application: str = DEFAULT_APPLICATION, http_adapter: requests.adapters.HTTPAdapter = None,
                     application_version: str = APP_VERSION):
            domain, verify = self.domain_and_verify(environment_or_domain)
            GsSession.__init__(self, domain, environment_or_domain, api_version=api_version, application=application,
                               verify=verify, http_adapter=http_adapter, application_version=application_version)

    class PassThroughGSSSOSession(KerberosSessionMixin, GsSession):

        def __init__(self, environment: str, token, api_version=API_VERSION,
                     application=DEFAULT_APPLICATION, http_adapter=None, csrf_token=None):
            domain, verify = self.domain_and_verify(environment)
            GsSession.__init__(self, domain, environment, api_version=api_version, application=application,
                               verify=verify, http_adapter=http_adapter)

            self.token = token
            self.csrf_token = csrf_token

        def _authenticate(self):
            if not (self.token and self.csrf_token):
                self._handle_cookies(self.token)
                return

            cookie = requests.cookies.create_cookie(domain='.gs.com', name='GSSSO', value=self.token)
            self._session.cookies.set_cookie(cookie)
            if self.csrf_token:
                cookie = requests.cookies.create_cookie(domain='.gs.com', name='MARQUEE-CSRF-TOKEN',
                                                        value=self.csrf_token)
                self._session.cookies.set_cookie(cookie)
                self._session.headers.update({'X-MARQUEE-CSRF-TOKEN': self.csrf_token})

except ModuleNotFoundError:
    pass

try:
    from gs_quant_auth.kerberos.session_kerberos import MQLoginMixin

    class MQLoginSession(MQLoginMixin, GsSession):

        def __init__(self, environment_or_domain: str, api_version: str = API_VERSION,
                     application: str = DEFAULT_APPLICATION, http_adapter: requests.adapters.HTTPAdapter = None,
                     application_version: str = APP_VERSION):
            domain, verify = self.domain_and_verify(environment_or_domain)
            env_config = self._config_for_environment(environment_or_domain)
            GsSession.__init__(self, env_config['MdsWebDomain'], environment_or_domain, api_version=api_version,
                               application=application, verify=verify, http_adapter=http_adapter,
                               application_version=application_version)


except ModuleNotFoundError:
    pass