使用twisted.web.AGENT无法向django服务器发起http请求

Question

我编写了一个基本的tcp服务器工厂、服务器客户端和服务，使用Twisted。TCP服务器充当Django服务器和另一个程序（我们称其为客户端程序）之间的中间件。

我的目标是：

1.客户端请求中间件TCP服务器；

2.它发送一个字符串作为请求主体；

3.中间件TCP服务器从请求中反序列化信息；

4.中间件将序列化信息进一步传递给Django服务器；

5.Django服务器响应中间件服务器，中间件服务器在序列化响应后将其传递给客户端。

我能够完成前三步，但无法向Django服务器发出任何HTTP请求。

以下是我的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)

以下是 test_service.py 文件。

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

以下是test_http_client.py文件的内容。

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

编辑 已删除依赖于与问题无关的其他代码的代码。

- HumptyDumptyEIZ

---

你能试着把这个缩减成一个 http://sscce.org 吗？这里缺了很多代码，所以我无法尝试运行你的示例。就此而言，在后端使用 Django 并没有什么区别：这只是 Twisted 发出 HTTP 请求。正如你所指出的那样，它在隔离状态下运作正常，因此一些与系统的其余部分的复杂交互会导致问题，而如果不完整地查看系统的其余部分，则无法确定具体情况。(尝试调试整个系统对其他人来说并不是真正有用的，因此您缩小问题范围得越多，就越好。) - Glyph

Answer 1

发现了一个错误。 以下是已更正的代码。

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           # instead of self.data += data
        self.forward(self.data)    # this is the right place to call this method which in turn fires the callback through which the request is made to the server.

    def connectionLost(self, reason): pass
        # this will not be called until the connection from client is ended. 
        # self.forward(self.data)

    def forward(self, data):
        if self.deferred is not None:
            d, self.deferred = self.deferred, None
            d.callback(data)

- HumptyDumptyEIZ

---

这段代码存在语法错误，所以我不确定它是否完全被纠正了 :). 我认为你可以完全消除 self.data？ - Glyph