examples/twisted/twisted_http_proxy.py

   1 """Listen on port 8888 and pretend to be an HTTP proxy.
   2 It even works for some pages.
   3
   4 Demonstrates how to
   5  * plug in eventlet into a twisted application (join_reactor)
   6  * call green functions from places where blocking calls
   7    are not allowed (deferToGreenThread)
   8  * use eventlet.green package which provides [some of] the
   9    standard library modules that don't block other greenlets.
  10 """
  11 import re
  12 from twisted.internet.protocol import Factory
  13 from twisted.internet import reactor
  14 from twisted.protocols import basic
  15
  16 from eventlet.twistedutil import deferToGreenThread
  17 from eventlet.twistedutil import join_reactor
  18 from eventlet.green import httplib
  19
  20 class LineOnlyReceiver(basic.LineOnlyReceiver):
  21
  22     def connectionMade(self):
  23         self.lines = []
  24
  25     def lineReceived(self, line):
  26         if line:
  27             self.lines.append(line)
  28         elif self.lines:
  29             self.requestReceived(self.lines)
  30             self.lines = []
  31
  32     def requestReceived(self, lines):
  33         request = re.match('^(\w+) http://(.*?)(/.*?) HTTP/1..$', lines[0])
  34         #print request.groups()
  35         method, host, path = request.groups()
  36         headers = dict(x.split(': ', 1) for x in lines[1:])
  37         def callback(result):
  38             self.transport.write(str(result))
  39             self.transport.loseConnection()
  40         def errback(err):
  41             err.printTraceback()
  42             self.transport.loseConnection()
  43         d = deferToGreenThread(http_request, method, host, path, headers=headers)
  44         d.addCallbacks(callback, errback)
  45
  46 def http_request(method, host, path, headers):
  47     conn = httplib.HTTPConnection(host)
  48     conn.request(method, path, headers=headers)
  49     response = conn.getresponse()
  50     body = response.read()
  51     print(method, host, path, response.status, response.reason, len(body))
  52     return format_response(response, body)
  53
  54 def format_response(response, body):
  55     result = "HTTP/1.1 %s %s" % (response.status, response.reason)
  56     for k, v in response.getheaders():
  57         result += '\r\n%s: %s' % (k, v)
  58     if body:
  59         result += '\r\n\r\n'
  60         result += body
  61         result += '\r\n'
  62     return result
  63
  64 class MyFactory(Factory):
  65     protocol = LineOnlyReceiver
  66
  67 print(__doc__)
  68 reactor.listenTCP(8888, MyFactory())
  69 reactor.run()