Problem with a client requesting a TCP service

[龚一涛]

This's an awesome tool, Thank you to all the contributors for their efforts!

But I'm experiencing some confusion in using it

I have a TCP service for receiving client requests (I'll give the code below), I've tried using the HTTP Native Client, and the Postman request receives a response from the server, but in resty it gives an error:

http_client_test.go:23: read tcp 172.27.175.75:46696->172.27.175.75:23360: read: connection reset by peer

TCP Server Code

# -*- coding: UTF-8 -*-
import socket


host = "0.0.0.0"   # 替换成自己的ip 地址
port = 23360
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))

while True:
    s.listen()
    # print("正在监听端口")
    conn, addr = s.accept()
    # print('连接的地址和端口：', addr)
    data = conn.recv(4096)
    data = data.decode()
    if not data:
        break
    # body_start = data.find("\r\n\r\n") + 4
    # body = data[body_start:]
    print('Accepted data：', data)
    
    print("\n")
    # conn.sendall(language.get(data, 'Nothing').encode())
    # conn.send()
    with open('received_request.txt', 'a') as request_file:
        request_file.write(data+'\n')
    # 响应行
    response_line = "HTTP/1.1 200 OK\r\n"

    # 响应头
    response_header = "Server:Python20WS/2.1\r\n"

    # 响应空行
    response_blank = "\r\n"

    # 响应主体
    response_body = "{'code': '0', 'msg': ''}"

    # 拼接响应报文
    response_data = response_line + response_header + response_blank + response_body
    # 发送响应报文
    conn.send((response_data.encode()))
    with open('sent_response.txt', 'a') as response_file:
        response_file.write(response_data+'\n')
    conn.close()
s.close()

Resty Test Code

var _once sync.Once
var _httpClient *resty.Client

func httpClient() *resty.Client {
	if _httpClient == nil {
		_once.Do(func() {
			_httpClient = resty.NewWithClient(&http.Client{Transport: http.DefaultTransport})
			_httpClient.SetTimeout(_defaultHTTPRequestTimeout)
			_httpClient.JSONMarshal = sonic.Marshal
			_httpClient.JSONUnmarshal = sonic.Unmarshal
			_httpClient.SetPreRequestHook(func(c *resty.Client, req *http.Request) error {
				req.Close = true
				return nil
			})
		})
	}
	return _httpClient
}

func TestHTTPClient(t *testing.T) {
	ticker := time.Tick(3 * time.Second)
	for {
		<-ticker
		if resp, err := httpClient().R().
			SetHeader("Content-Type", "text/plain").
			SetBody(strings.NewReader(`Hi`)).
			SetContentLength(true).
			Post("http://172.27.175.75:23360"); err != nil {
			t.Log(err)
		} else {
			t.Log(resp)
		}
		return
	}
}

Native Go HTTP Client Test Code

func TestHTTPNative(t *testing.T) {
	url := "http://172.27.175.75:23360"
	method := "POST"

	payload := strings.NewReader(`Hi`)

	req, err := http.NewRequest(method, url, payload)

	if err != nil {
		fmt.Println(err)
		return
	}
	req.Header.Add("Content-Type", "text/plain")
	req.Header.Add("Connection", "close")

	res, err := httpClient().GetClient().Do(req)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer res.Body.Close()

	time.Sleep(2 * time.Second)

	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(string(body))
}

[Jeevanandam M.]

@uptutu Can you change this line
from

_httpClient = resty.NewWithClient(&http.Client{Transport: http.DefaultTransport})

to

_httpClient = resty.New()

Try and share your feedback.

[龚一涛]

@uptutu Can you change this line from

_httpClient = resty.NewWithClient(&http.Client{Transport: http.DefaultTransport})

to

_httpClient = resty.New()

Try and share your feedback.

I use resty.New() by default, but no matter what I change, the problem persists!

[Jeevanandam M.]

@uptutu I see then I will have to try your code snippet(s) locally. Let me give it a try!

[Jeevanandam M.]

@uptutu I have tried your code; it does work correctly for the default HTTP and Resty client. Regarding the connection reset by a peer, you should look into it at your end.

I have tried this on my end (I commented out the lines not present on my end and your code).

package main

import (
	"fmt"
	"io"
	"net/http"
	"strings"
	"sync"
	"time"

	"github.com/go-resty/resty/v2"
)

func main() {
	url := "http://0.0.0.0:23360"
	method := "POST"

	payload := strings.NewReader(`Hi`)

	req, err := http.NewRequest(method, url, payload)

	if err != nil {
		fmt.Println(err)
		return
	}
	req.Header.Add("Content-Type", "text/plain")
	req.Header.Add("Connection", "close")

	res, err := httpClient().GetClient().Do(req)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer res.Body.Close()

	time.Sleep(2 * time.Second)

	body, err := io.ReadAll(res.Body)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println("Response from server:", string(body))

	// Resty Code
	resp, err := httpClient().R().
		SetHeader("Content-Type", "text/plain").
		SetBody(strings.NewReader(`Hi`)).
		SetContentLength(true).
		Post(url)
	fmt.Println("Resty code, response from server:", resp, err)
}

var _once sync.Once
var _httpClient *resty.Client

func httpClient() *resty.Client {
	if _httpClient == nil {
		_once.Do(func() {
			_httpClient = resty.NewWithClient(&http.Client{Transport: http.DefaultTransport})
			// _httpClient.SetTimeout(_defaultHTTPRequestTimeout)
			// _httpClient.JSONMarshal = sonic.Marshal
			// _httpClient.JSONUnmarshal = sonic.Unmarshal
			_httpClient.SetPreRequestHook(func(c *resty.Client, req *http.Request) error {
				req.Close = true
				return nil
			})
		})
	}
	return _httpClient
}

Output:

Response from server: {'code': '0', 'msg': ''}
Resty code, response from server: {'code': '0', 'msg': ''} read tcp 127.0.0.1:59384->127.0.0.1:23360: read: connection reset by peer