added examples/twisted_http_proxy.py

examples/twisted_http_proxy.py

@@ -0,0 +1,67 @@
+"""Listen on port 8888 and pretend to be an HTTP proxy.
+It even works for some pages.
+
+Demonstrates how to
+ * plug in eventlet into a twisted application (join_reactor)
+ * call green functions from places where blocking calls
+   are not allowed (deferToGreenThread)
+ * use eventlet.green package which provides [some of] the
+   standard library modules that don't block other greenlets.
+"""
+import re
+from twisted.internet.protocol import Factory
+from twisted.internet import reactor
+from twisted.protocols import basic
+
+from eventlet.twistedutil import deferToGreenThread
+from eventlet.twistedutil import join_reactor
+from eventlet.green import httplib
+
+class LineOnlyReceiver(basic.LineOnlyReceiver):
+
+    def connectionMade(self):
+        self.lines = []
+
+    def lineReceived(self, line):
+        if line:
+            self.lines.append(line)
+        elif self.lines:
+            self.requestReceived(self.lines)
+            self.lines = []
+
+    def requestReceived(self, lines):
+        request = re.match('^(\w+) http://(.*?)(/.*?) HTTP/1..$', lines[0])
+        print request.groups()
+        method, host, path = request.groups()
+        headers = dict(x.split(': ', 1) for x in lines[1:])
+        def callback(result):
+            self.transport.write(str(result))
+            self.transport.loseConnection()
+        def errback(err):
+            err.printTraceback()
+            self.transport.loseConnection()
+        d = deferToGreenThread(http_request, method, host, path, headers=headers)
+        d.addCallbacks(callback, errback)
+
+def http_request(method, host, path, headers):
+    conn = httplib.HTTPConnection(host)
+    conn.request(method, path, headers=headers)
+    response = conn.getresponse()
+    return format_response(response)
+
+def format_response(response):
+    body = response.read()
+    result = "HTTP/1.1 %s %s" % (response.status, response.reason)
+    for k, v in response.getheaders():
+        result += '\r\n%s: %s' % (k, v)
+    if body:
+        result += '\r\n\r\n'
+        result += body
+        result += '\r\n'
+    return result
+
+class MyFactory(Factory):
+    protocol = LineOnlyReceiver
+
+reactor.listenTCP(8888, MyFactory())
+reactor.run()