Source Code for Module restkit.contrib.wsgi_proxy

  1  # -*- coding: utf-8 - 
  2  # 
  3  # This file is part of restkit released under the MIT license. 
  4  # See the NOTICE for more information. 
  5   
  6  import urlparse 
  7   
  8  try: 
  9      from cStringIO import StringIO 
 10  except ImportError: 
 11      from StringIO import StringIO 
 12   
 13  from restkit.client import Client 
 14  from restkit.conn import MAX_BODY 
 15  from restkit.util import rewrite_location 
 16   
 17  ALLOWED_METHODS = ['GET', 'HEAD', 'POST', 'PUT', 'DELETE'] 
 18   
 19  BLOCK_SIZE = 4096 * 16 
 20   
 21  WEBOB_ERROR = ("Content-Length is set to -1. This usually mean that WebOb has " 
 22          "already parsed the content body. You should set the Content-Length " 
 23          "header to the correct value before forwarding your request to the " 
 24          "proxy: ``req.content_length = str(len(req.body));`` " 
 25          "req.get_response(proxy)") 
 26   
 27 -class Proxy(object): 
 28      """A proxy wich redirect the request to SERVER_NAME:SERVER_PORT 
 29      and send HTTP_HOST header""" 
 30   
 31 -    def __init__(self, manager=None, allowed_methods=ALLOWED_METHODS, 
 32              strip_script_name=True,  **kwargs): 
 33          self.allowed_methods = allowed_methods 
 34          self.strip_script_name = strip_script_name 
 35          self.client = Client(**kwargs) 
 36   
 37 -    def extract_uri(self, environ): 
 38          port = None 
 39          scheme = environ['wsgi.url_scheme'] 
 40          if 'SERVER_NAME' in environ: 
 41              host = environ['SERVER_NAME'] 
 42          else: 
 43              host = environ['HTTP_HOST'] 
 44          if ':' in host: 
 45              host, port = host.split(':') 
 46   
 47          if not port: 
 48              if 'SERVER_PORT' in environ: 
 49                  port = environ['SERVER_PORT'] 
 50              else: 
 51                  port = scheme == 'https' and '443' or '80' 
 52   
 53          uri = '%s://%s:%s' % (scheme, host, port) 
 54          return uri 
 55   
 56 -    def __call__(self, environ, start_response): 
 57          method = environ['REQUEST_METHOD'] 
 58          if method not in self.allowed_methods: 
 59              start_response('403 Forbidden', ()) 
 60              return [''] 
 61   
 62          if self.strip_script_name: 
 63              path_info = '' 
 64          else: 
 65              path_info = environ['SCRIPT_NAME'] 
 66          path_info += environ['PATH_INFO'] 
 67   
 68          query_string = environ['QUERY_STRING'] 
 69          if query_string: 
 70              path_info += '?' + query_string 
 71   
 72          host_uri = self.extract_uri(environ) 
 73          uri = host_uri + path_info 
 74   
 75          new_headers = {} 
 76          for k, v in environ.items(): 
 77              if k.startswith('HTTP_'): 
 78                  k = k[5:].replace('_', '-').title() 
 79                  new_headers[k] = v 
 80   
 81   
 82          ctype = environ.get("CONTENT_TYPE") 
 83          if ctype and ctype is not None: 
 84              new_headers['Content-Type'] = ctype 
 85   
 86          clen = environ.get('CONTENT_LENGTH') 
 87          te =  environ.get('transfer-encoding', '').lower() 
 88          if not clen and te != 'chunked': 
 89              new_headers['transfer-encoding'] = 'chunked' 
 90          elif clen: 
 91              new_headers['Content-Length'] = clen 
 92   
 93          if new_headers.get('Content-Length', '0') == '-1': 
 94              raise ValueError(WEBOB_ERROR) 
 95   
 96          response = self.client.request(uri, method, body=environ['wsgi.input'], 
 97                  headers=new_headers) 
 98   
 99          if 'location' in response: 
100              if self.strip_script_name: 
101                  prefix_path = environ['SCRIPT_NAME'] 
102   
103              new_location = rewrite_location(host_uri, response.location, 
104                      prefix_path=prefix_path) 
105   
106              headers = [] 
107              for k, v in response.headerslist: 
108                  if k.lower() == 'location': 
109                      v = new_location 
110                  headers.append((k, v)) 
111          else: 
112              headers = response.headerslist 
113   
114          start_response(response.status, headers) 
115   
116          if method == "HEAD": 
117              return StringIO() 
118   
119          return response.tee() 
120   
121 -class TransparentProxy(Proxy): 
122      """A proxy based on HTTP_HOST environ variable""" 
123   
124 -    def extract_uri(self, environ): 
125          port = None 
126          scheme = environ['wsgi.url_scheme'] 
127          host = environ['HTTP_HOST'] 
128          if ':' in host: 
129              host, port = host.split(':') 
130   
131          if not port: 
132              port = scheme == 'https' and '443' or '80' 
133   
134          uri = '%s://%s:%s' % (scheme, host, port) 
135          return uri 
136   
137   
138 -class HostProxy(Proxy): 
139      """A proxy to redirect all request to a specific uri""" 
140   
141 -    def __init__(self, uri, **kwargs): 
142          super(HostProxy, self).__init__(**kwargs) 
143          self.uri = uri.rstrip('/') 
144          self.scheme, self.net_loc = urlparse.urlparse(self.uri)[0:2] 
145   
146 -    def extract_uri(self, environ): 
147          environ['HTTP_HOST'] = self.net_loc 
148          return self.uri 
149   
150 -def get_config(local_config): 
151      """parse paste config""" 
152      config = {} 
153      allowed_methods = local_config.get('allowed_methods', None) 
154      if allowed_methods: 
155          config['allowed_methods'] = [m.upper() for m in allowed_methods.split()] 
156      strip_script_name = local_config.get('strip_script_name', 'true') 
157      if strip_script_name.lower() in ('false', '0'): 
158          config['strip_script_name'] = False 
159      config['max_connections'] = int(local_config.get('max_connections', '5')) 
160      return config 
161   
162 -def make_proxy(global_config, **local_config): 
163      """TransparentProxy entry_point""" 
164      config = get_config(local_config) 
165      return TransparentProxy(**config) 
166   
167 -def make_host_proxy(global_config, uri=None, **local_config): 
168      """HostProxy entry_point""" 
169      uri = uri.rstrip('/') 
170      config = get_config(local_config) 
171      return HostProxy(uri, **config) 
172