py_jama_rest_client.core

  1import math
  2
  3import requests
  4import time
  5import logging
  6
  7__DEBUG__ = False
  8
  9py_jama_rest_client_logger = logging.getLogger('py_jama_rest_client-core')
 10
 11
 12class CoreException(Exception):
 13    """This is the base class for all exceptions raised by the Core"""
 14
 15    def __init__(self, message, status_code=None, reason=None):
 16        super(CoreException, self).__init__(message)
 17        self.status_code = status_code
 18        self.reason = reason
 19
 20
 21class UnauthorizedTokenException(CoreException):
 22    """This exception is thrown whenever fetching the oauth token returns a 401 unauthorized response."""
 23    pass
 24
 25
 26class Core:
 27    """ This Class will contain a collection of methods that interact directly with the Jama API and return A Requests
 28    Response Object.  This class will give the user more fine grained access to the JAMA API.  For more information
 29    on the Requests library visit: http://docs.python-requests.org/en/master/"""
 30
 31    def __init__(self, host_name, user_credentials, api_version='/rest/v1/', oauth=False, verify=True):
 32        # Instance variables
 33        self.__api_version = api_version
 34        self.__host_name = host_name + self.__api_version
 35        self.__credentials = user_credentials
 36        self.__oauth = oauth
 37        self.__verify = verify
 38        self.__session = requests.Session()
 39
 40        # Setup OAuth if needed.
 41        if self.__oauth:
 42            self.__token_host = host_name + '/rest/oauth/token'
 43            self.__token = None
 44            self.__get_fresh_token()
 45
 46    def delete(self, resource, **kwargs):
 47        """ This method will perform a delete operation on the specified resource"""
 48        url = self.__host_name + resource
 49        kwargs['verify'] = self.__verify
 50
 51        if self.__oauth:
 52            self.__check_oauth_token()
 53            kwargs['headers'] = self.__add_auth_header(**kwargs)
 54            return self.__session.delete(url, **kwargs)
 55
 56        return self.__session.delete(url, auth=self.__credentials, **kwargs)
 57
 58    def get(self, resource, params=None, **kwargs):
 59        """ This method will perform a get operation on the specified resource"""
 60        url = self.__host_name + resource
 61        kwargs['verify'] = self.__verify
 62
 63        if self.__oauth:
 64            self.__check_oauth_token()
 65            kwargs['headers'] = self.__add_auth_header(**kwargs)
 66            return self.__session.get(url, params=params, **kwargs)
 67
 68        return self.__session.get(url, auth=self.__credentials, params=params, **kwargs)
 69
 70    def patch(self, resource, params=None, data=None, json=None, **kwargs):
 71        """ This method will perform a patch operation to the specified resource"""
 72        url = self.__host_name + resource
 73        kwargs['verify'] = self.__verify
 74
 75        if self.__oauth:
 76            self.__check_oauth_token()
 77            kwargs['headers'] = self.__add_auth_header(**kwargs)
 78            return self.__session.patch(url, params=params, data=data, json=json, **kwargs)
 79
 80        return self.__session.patch(url, auth=self.__credentials, params=params, data=data, json=json, **kwargs)
 81
 82    def post(self, resource, params=None, data=None, json=None, **kwargs):
 83        """ This method will perform a post operation to the specified resource."""
 84        url = self.__host_name + resource
 85        kwargs['verify'] = self.__verify
 86
 87        if self.__oauth:
 88            self.__check_oauth_token()
 89            kwargs['headers'] = self.__add_auth_header(**kwargs)
 90            return self.__session.post(url, params=params, data=data, json=json, **kwargs)
 91
 92        return self.__session.post(url, auth=self.__credentials, params=params, data=data, json=json, **kwargs)
 93
 94    def put(self, resource, params=None, data=None, json=None, **kwargs):
 95        """ This method will perform a put operation to the specified resource"""
 96        url = self.__host_name + resource
 97        kwargs['verify'] = self.__verify
 98
 99        if self.__oauth:
100            self.__check_oauth_token()
101            kwargs['headers'] = self.__add_auth_header(**kwargs)
102            return self.__session.put(url, data=data, params=params, json=json, **kwargs)
103
104        return self.__session.put(url, auth=self.__credentials, data=data, params=params, json=json, **kwargs)
105
106    def __check_oauth_token(self):
107
108        if self.__token is None:
109            self.__get_fresh_token()
110
111        else:
112            time_elapsed = time.time() - self.__token_acquired_at
113            time_remaining = self.__token_expires_in - time_elapsed
114            if time_remaining < 60:
115                # if less than a minute remains, just get another token.
116                self.__get_fresh_token()
117
118    def __get_fresh_token(self):
119        """This method will fetch a new oauth bearer token from the oauth token server."""
120        data = {
121            'grant_type': 'client_credentials'
122        }
123
124        # By getting the system time before we get the token we avoid a potential bug where the token may be expired.
125        time_before_request = time.time()
126
127        # Post to the token server, check if authorized
128        try:
129            response = requests.post(self.__token_host, auth=self.__credentials, data=data, verify=self.__verify)
130            response.raise_for_status()
131        except requests.exceptions.HTTPError as err:
132            message = "Unable to fetch token: "
133            raise UnauthorizedTokenException(message + str(err), response.status_code)
134
135        # If success get relevant data
136        if response.status_code in [200, 201]:
137            response_json = response.json()
138            self.__token = response_json['access_token']
139            self.__token_expires_in = response_json['expires_in']
140            self.__token_acquired_at = math.floor(time_before_request)
141
142        else:
143            py_jama_rest_client_logger.error('Failed to retrieve OAuth Token')
144
145    def __add_auth_header(self, **kwargs):
146        headers = kwargs.get('headers')
147        if headers is None:
148            headers = {}
149        headers['Authorization'] = 'Bearer ' + self.__token
150        return headers