Source Code for Module cm_api.resource

  1  # Licensed to Cloudera, Inc. under one 
  2  # or more contributor license agreements.  See the NOTICE file 
  3  # distributed with this work for additional information 
  4  # regarding copyright ownership.  Cloudera, Inc. licenses this file 
  5  # to you under the Apache License, Version 2.0 (the 
  6  # "License"); you may not use this file except in compliance 
  7  # with the License.  You may obtain a copy of the License at 
  8  # 
  9  #     http://www.apache.org/licenses/LICENSE-2.0 
 10  # 
 11  # Unless required by applicable law or agreed to in writing, software 
 12  # distributed under the License is distributed on an "AS IS" BASIS, 
 13  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 14  # See the License for the specific language governing permissions and 
 15  # limitations under the License. 
 16   
 17  try: 
 18    import json 
 19  except ImportError: 
 20    import simplejson as json 
 21  import logging 
 22  import posixpath 
 23   
 24  LOG = logging.getLogger(__name__) 
 25   
 26   
 27 -class Resource(object): 
 28    """ 
 29    Encapsulates a resource, and provides actions to invoke on it. 
 30    """ 
 31 -  def __init__(self, client, relpath=""): 
 32      """ 
 33      @param client: A Client object. 
 34      @param relpath: The relative path of the resource. 
 35      """ 
 36      self._client = client 
 37      self._path = relpath.strip('/') 
 38   
 39    @property 
 40 -  def base_url(self): 
 41      return self._client.base_url 
 42   
 43 -  def _join_uri(self, relpath): 
 44      if relpath is None: 
 45        return self._path 
 46      return self._path + posixpath.normpath('/' + relpath) 
 47   
 48 -  def invoke(self, method, relpath=None, params=None, data=None, headers=None): 
 49      """ 
 50      Invoke an API method. 
 51      @return: Raw body or JSON dictionary (if response content type is JSON). 
 52      """ 
 53      path = self._join_uri(relpath) 
 54      resp = self._client.execute(method, 
 55                                  path, 
 56                                  params=params, 
 57                                  data=data, 
 58                                  headers=headers) 
 59      try: 
 60        body = resp.read() 
 61      except Exception, ex: 
 62        raise Exception("Command '%s %s' failed: %s" % 
 63                        (method, path, ex)) 
 64   
 65      self._client.logger.debug( 
 66          "%s Got response: %s%s" % 
 67          (method, body[:32], len(body) > 32 and "..." or "")) 
 68   
 69      # Is the response application/json? 
 70      if len(body) != 0 and \ 
 71            resp.info().getmaintype() == "application" and \ 
 72            resp.info().getsubtype() == "json": 
 73        try: 
 74          json_dict = json.loads(body) 
 75          return json_dict 
 76        except Exception, ex: 
 77          self._client.logger.exception('JSON decode error: %s' % (body,)) 
 78          raise ex 
 79      else: 
 80        return body 
 81   
 82   
 83 -  def get(self, relpath=None, params=None): 
 84      """ 
 85      Invoke the GET method on a resource. 
 86      @param relpath: Optional. A relative path to this resource's path. 
 87      @param params: Key-value data. 
 88   
 89      @return: A dictionary of the JSON result. 
 90      """ 
 91      return self.invoke("GET", relpath, params) 
 92   
 93   
 94 -  def delete(self, relpath=None, params=None): 
 95      """ 
 96      Invoke the DELETE method on a resource. 
 97      @param relpath: Optional. A relative path to this resource's path. 
 98      @param params: Key-value data. 
 99   
100      @return: A dictionary of the JSON result. 
101      """ 
102      return self.invoke("DELETE", relpath, params) 
103   
104   
105 -  def post(self, relpath=None, params=None, data=None, contenttype=None): 
106      """ 
107      Invoke the POST method on a resource. 
108      @param relpath: Optional. A relative path to this resource's path. 
109      @param params: Key-value data. 
110      @param data: Optional. Body of the request. 
111      @param contenttype: Optional. 
112   
113      @return: A dictionary of the JSON result. 
114      """ 
115      return self.invoke("POST", relpath, params, data, 
116                         self._make_headers(contenttype)) 
117   
118   
119 -  def put(self, relpath=None, params=None, data=None, contenttype=None): 
120      """ 
121      Invoke the PUT method on a resource. 
122      @param relpath: Optional. A relative path to this resource's path. 
123      @param params: Key-value data. 
124      @param data: Optional. Body of the request. 
125      @param contenttype: Optional. 
126   
127      @return: A dictionary of the JSON result. 
128      """ 
129      return self.invoke("PUT", relpath, params, data, 
130                         self._make_headers(contenttype)) 
131   
132   
133 -  def _make_headers(self, contenttype=None): 
134      if contenttype: 
135        return { 'Content-Type': contenttype } 
136      return None 
137