golang实现的ab测试http代理工具

压测工具ab不能统计http请求的错误情况，包括http状态码错误和响应正文的错误关键字。

所以加层代理用于统计http错误情况，重在统计错误情况，而不是代理的性能，主要用于功能接口的测试，比如测试一下请求多少次接口会返回空数据。

被认为是错误的情况：

1、非200状态码

2、响应正文里不包含表示正确关键字

3、响应正文里包含表示错误关键字

编译方式：

go build go_ab_proxy.go

启动方式：

./go_ab_proxy

./go_ab_proxy -okstr 'code":"0'

./go_ab_proxy -failstr error

测试方式：

ab -c 2 -n 10 -X 127.0.0.1:9090 'http://www.baidu.com/'

curl -x 127.0.0.1:9090 'http://www.baidu.com/'

查看错误统计：

ctrl-c或kill结束进程时显示统计结果。

golang代码如下：

go_ab_proxy.go

package main
import (
	"bytes"
	"flag"
	"fmt"
	"net/http"
	"net/http/httputil"
	"os"
	"os/signal"
	"strings"
	"sync/atomic"
	"syscall"
)
var (
	successCount int32
	failCount    int32
	okStr        = flag.String("okstr", "", "indicate ok string")
	failStr      = flag.String("failstr", "", "indicate fail string")
)
func main() {
	flag.Parse()
	if *okStr != "" && *failStr != "" {
		fmt.Printf("-okstr and -failstr only one can be used\n")
		return
	}
	http.HandleFunc("/", middleware(func(w http.ResponseWriter, r *http.Request) {
		proxy := httputil.NewSingleHostReverseProxy(r.URL)
		proxy.ServeHTTP(w, r)
	}))
	go installSignal()
	err := http.ListenAndServe(":9090", nil)
	if err != nil {
		fmt.Printf("proxy server start fail, %v\n", err)
		return
	}
}
func middleware(handler http.HandlerFunc) http.HandlerFunc {
	return func(response http.ResponseWriter, request *http.Request) {
		responseWrapper := &ResponseWithRecorder{
			ResponseWriter: response,
			StatusCode:     http.StatusOK,
			Body:           bytes.Buffer{},
		}
		handler(responseWrapper, request)
		if responseWrapper.StatusCode != http.StatusOK {
			atomic.AddInt32(&failCount, 1)
		} else {
			if *okStr == "" && *failStr == "" {
				atomic.AddInt32(&successCount, 1)
				return
			}
			resBody := string(responseWrapper.Body.Bytes())
			if *okStr != "" && !strings.Contains(resBody, *okStr) {
				atomic.AddInt32(&failCount, 1)
				return
			} else if *failStr != "" && strings.Contains(resBody, *failStr) {
				atomic.AddInt32(&failCount, 1)
				return
			}
			atomic.AddInt32(&successCount, 1)
		}
	}
}
func installSignal() {
	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
	go func() {