如何打开一个TCP套接字来监听一个连接并返回结果？

Question

我正在尝试编写一个打开端口（戳第三方）的脚本，然后捕获并返回他们的 http 请求中有趣的部分，以便我的主线程继续。

第三方认为我们是一个http网络服务器。到目前为止，我正在尝试使用 TCPServer.SocketServer （或 http.server.HTTPServer）来执行此操作。到目前为止，对于“戳”部分，我正在使用浏览器手动点击它。但问题是：

如何将数据返回到主线程？

由于socketserver.TCPServer消耗的是一个类，而不是类的实例，所以我不知道如何将数据传回父线程。这也许就是并发编程101？我希望“返回”该值，但我想一些跨线程共享变量就可以了。

当前的代码看起来很像：

async def fourtytwo(text):
    pprint.pp(text)
    return 42


class MyTCPHandler(socketserver.BaseRequestHandler):
    data = None

    def handle(self):
        self.data = self.request.recv(1024).strip()
        print("{} wrote:".format(self.client_address[0]))
        print(self.data)
        # just send back the same data, but upper-cased
        self.request.sendall(self.data.upper())


async def listen_for_response():
    logger = logging.getLogger(inspect.currentframe().f_code.co_name)
    logger.debug("Listening on port: %s", LISTENING_PORT)

    with socketserver.TCPServer(("localhost", LISTENING_PORT), MyTCPHandler) as server:
        server.handle_request()
        code = MyTCPHandler.data
        logger.debug("Code is: %s", code)

    logger.debug("Exiting")
    return code


async def flow(config):
    onetwo = await asyncio.gather(
        fourtytwo("one"),
        asyncio.create_task(listen_for_response()),
    )
    pprint.pp(onetwo)

输出：

DEBUG:listen_for_response:Listening on port: 4200
127.0.0.1 wrote:
b'GET / HTTP/1.1\r\nHost: localhost:4200\r\nUser-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:97.0) Gecko/20100101 Firefox/97.0\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8\r\nAccept-Language: en-US,en;q=0.5\r\nAccept-Encoding: gzip, deflate\r\nDNT: 1\r\nConnection: keep-alive\r\nUpgrade-Insecure-Requests: 1\r\nSec-Fetch-Dest: document\r\nSec-Fetch-Mode: navigate\r\nSec-Fetch-Site: none\r\nSec-Fetch-User: ?1\r\nCache-Control: max-age=0'
DEBUG:listen_for_response:Code is: None
DEBUG:listen_for_response:Exiting
'one'
[42, None]

Answer 1

放弃 socketserver 并直接打开套接字更容易，也许是必要的：

async def listen_once():
    """Open a TCP/IP socket on a port and capture one incoming request.

    Responds by echoing the request back in uppercase.

    Returns a list of strings like the text of the incoming request.
    """
    logger = logging.getLogger(inspect.currentframe().f_code.co_name)
    logger.debug("Listening on port: %s", LISTENING_PORT)

    s = socket.create_server(("localhost", LISTENING_PORT))
    conn, addr = s.accept()
    with conn:
        request = conn.recv(1024)
        conn.sendall(request.upper())
    s.shutdown(socket.SHUT_RD)
    s.close()

    lines = [line.decode("utf-8").strip() for line in request.split(b"\r\n")]
    for line in lines:
        logger.debug(line)
    return lines

# Start listening
listener = asyncio.create_task(listen_once())

# Do the poke
response = requests.get(uri)
logger.debug(response.text)

# Capture the request sent to the listener (which is a reaction to the poke)
await listener
request_sent_to_listener = listener.result()