Python twisted forward http post body to tcp port

Question

I have an echo server running in localhost at port 9999. I am developing a web server using twisted ( I am new to twisted and python in general). The client will stream the data using chunked encoding with HTTP. What I want the server to do is to send this data to port 9999 and get the response from there and write back as http response. But I even can't make the sending part work. This is what i have done till now.

from twisted.web import server, resource
from twisted.internet import reactor, endpoints
from twisted.internet.protocol import Protocol, Factory

class Clientp(Protocol):
    def __init__(self, req):
        self.req = req

    def connectionMade(self):
        self.transport.writeSequence(self.req.content.read())

    def dataReceived(self,data):
        print ("+ got reply" + str(data))
        # I have to send the data via resposne here

class Counter(resource.Resource):
    isLeaf = True
    numberRequests = 0

    def render_POST(self, request):
        def clientProtocol():
            return Clientp(request)
        endpoint = endpoints.TCP4ClientEndpoint(reactor, "127.0.0.1", 9999)
        endpoint.connect(Factory.forProtocol(clientProtocol))
        return server.NOT_DONE_YET

endpoints.serverFromString(reactor, "tcp:8000").listen(server.Site(Counter()))
reactor.run()

I can't write the post content (request.content.read()) to the TCP endpoint. I'm getting TypeError("Data must be bytes") error. Any thoughts

Jean-Paul Calderone Jean-Paul Calderone · Accepted Answer · 2021-08-13T11:43:24

def connectionMade(self):
    self.transport.writeSequence(self.req.content.read())

ITransport.writeSequence accepts an iterable of bytes. IRequest.content.read returns a bytes object.

You get the error TypeError("Data must be bytes") because iterating over bytes in Python 3 results in integers. It is these integers that the implementation is complaining about.

You should just use ITransport.write, instead.

Python twisted forward http post body to tcp port

1 Answers