I have written a basic tcp server factory, server client and a service using
twisted. The tcp server acts as the middleware between a django server and an
another program (let's call it client program).
What I want to achieve -
1.client requests the middleware tcp server;
2.it sends a string as the request body;
3.the middleware tcp server deserializes information from the request.
4.middleware furthers the serialized information to the django server.
5.The django server then responds to the middleware server which furthers the
response to the client after serializing the response.
I am able to reach till step 3, but am unable to make any http request to the
django server.
The following is my middleware.py
from twisted.internet.protocol import ServerFactory
from twisted.internet.protocol import Protocol
from test_service import MyService
class TCPServerProtocol(Protocol):
data = ''
def connectionMade(self):
self.deferred = self.factory.service.deferred
self.deferred.addCallback(self.factory.service.s)
self.deferred.addCallback(self.transport.write)
self.deferred.addBoth(lambda r: self.transport.loseConnection)
def dataReceived(self, data):
self.data += data
def connectionLost(self, reason):
self.forward(self.data)
def forward(self, data):
if self.deferred is not None:
d, self.deferred = self.deferred, None
d.callback(data)
class TCPServerFactory(ServerFactory):
protocol = TCPServerProtocol
def __init__(self, service):
self.service = service
def runserver(ip, port):
iface = {'home': '192.168.0.104', 'work': '127.0.0.1'}
service = MyService()
factory = TCPServerFactory(service)
from twisted.internet import reactor
reactor.listenTCP(port=port, factory=factory, interface=iface[ip])
reactor.run()
if __name__ == '__main__':
import sys
ip = sys.argv[1]
port = int(sys.argv[2])
runserver(ip, port)
The following is test_service.py
from twisted.internet.defer import Deferred
from test_http_client import HTTPClientFactory
class MyService(object):
def __init__(self):
self.deferred = Deferred()
def s(self, data):
kwargs = {}
kwargs['url'] = b'http://127.0.0.1:8000/some/end/point'
kwargs['url'] = kwargs['url'].encode('latin-1')
kwargs['method'] = 'POST'
kwargs['data'] = data
client = HTTPClientFactory(**kwargs)
d = client.deferred
return d
The following is test_http_client.py
from StringIO import StringIO
import json
from twisted.internet.protocol import Protocol
from twisted.internet.defer import Deferred
from twisted.web.client import Agent, FileBodyProducer
from twisted.web.http_headers import Headers
class HTTPClientProtocol(Protocol):
def __init__(self, finished):
self.finished = finished
self.data = ''
def dataReceived(self, data):
print '----------Data Received by HTTPClientProtocol----------'
print data
self.data += data
def connectionLost(self, reason):
print '----------HTTP Client connection Lost----------'
print reason.getErrorMessage()
if self.finished is not None:
print 'finished is not None'
f, self.finished = self.finished, None
f.callback(self.data)
class HTTPClientFactory(object):
"""
Class handling communication with HTTP server.
"""
def __init__(self, **kwargs):
data = kwargs['data']
try:
body = FileBodyProducer(StringIO(json.dumps(data)))
print '----------Request body object created----------'
except Exception as e:
print '----------Request body object creation FAILURE----------'
print e
return e
url = kwargs.get('url', None)
method = kwargs.get('method', None)
from twisted.internet import reactor
agent = Agent(reactor)
if not data:
body = None
self.deferred = agent.request(method,
url,
Headers({'Content-Type':
['application/json']}),
bodyProducer=body)
self.deferred.addCallback(self.get_response)
def get_response(self, response):
print 'Response received'
finished = Deferred()
response.deliverBody(HTTPClientProtocol(finished))
return finished
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