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| package main
import (
"bytes"
"context"
"errors"
"flag"
"fmt"
"io"
"log"
"net/http"
"net/url"
"net"
"os"
"strings"
"sync"
"time"
"crypto/tls"
"gopkg.in/natefinch/lumberjack.v2"
"gopkg.in/yaml.v3"
)
type Config struct {
Server struct {
Port int `yaml:"port"`
} `yaml:"server"`
Log struct {
Enabled bool `yaml:"enabled"`
File string `yaml:"file"`
MaxSizeMB int `yaml:"maxsize"`
MaxBackups int `yaml:"maxbackups"`
MaxAgeDays int `yaml:"maxage"`
Compress bool `yaml:"compress"`
} `yaml:"log"`
Reload int `yaml:"reload"`
}
var (
port = flag.Int("port", 8888, "监听端口号")
logEnabled = flag.Bool("log", true, "是否启用日志记录")
logFile = flag.String("logfile", "", "日志文件路径")
logMaxSizeMB = flag.Int("log.maxsize", 10, "日志文件大小限制（MB）")
logMaxBackups = flag.Int("log.maxbackups", 3, "保留的最大备份文件数")
logMaxAgeDays = flag.Int("log.maxage", 28, "保留日志文件的最大天数")
logCompress = flag.Bool("log.compress", true, "是否压缩日志文件")
configFilePath = flag.String("config", "", "YAML配置文件路径")
Reload = flag.Int("reload", 30, "配置文件重新加载间隔（秒")
serverCtx, cancel = context.WithCancel(context.Background())
logConfigMutex sync.Mutex
cfg Config
)
var ErrBrokenPipe = errors.New("broken pipe")
var bufferPool = sync.Pool{
New: func() interface{} {
return make([]byte, defaultBufferSize)
},
}
const defaultBufferSize = 128 * 1024
func main() {
flag.Parse()
if *configFilePath != "" {
err := loadConfig(*configFilePath)
if err != nil {
log.Fatalf("读取YAML配置文件失败: %v", err)
}
} else {
cfg.Server.Port = *port
cfg.Log.Enabled = *logEnabled
cfg.Log.File = *logFile
cfg.Log.MaxSizeMB = *logMaxSizeMB
cfg.Log.MaxBackups = *logMaxBackups
cfg.Log.MaxAgeDays = *logMaxAgeDays
cfg.Log.Compress = *logCompress
cfg.Reload = *Reload
}
setupLogger()
go watchConfigFile(*configFilePath)
http.HandleFunc("/", handler)
go func() {
if err := startHTTPServer(serverCtx); err != nil {
log.Fatalf("启动HTTP服务器失败: %v", err)
}
}()
<-serverCtx.Done()
}
func loadConfig(configPath string) error {
yamlData, err := os.ReadFile(configPath)
if err != nil {
return err
}
var newCfg Config
err = yaml.Unmarshal(yamlData, &newCfg)
if err != nil {
return err
}
logConfigMutex.Lock()
cfg = newCfg
logConfigMutex.Unlock()
setupLogger()
return nil
}
func watchConfigFile(configPath string) {
if configPath == "" {
return
}
ticker := time.NewTicker(time.Duration(cfg.Reload) * time.Second)
defer ticker.Stop()
lastModifiedTime := time.Now()
for range ticker.C {
fileInfo, err := os.Stat(configPath)
if err != nil {
log.Printf("无法获取配置文件信息: %v", err)
continue
}
if fileInfo.ModTime().After(lastModifiedTime) {
lastModifiedTime = fileInfo.ModTime()
log.Println("检测到配置文件修改，重新加载配置...")
err := loadConfig(configPath)
if err != nil {
log.Printf("重新加载配置文件失败: %v", err)
} else {
log.Println("配置文件重新加载完成")
serverCtx, cancel = context.WithCancel(context.Background())
go func() {
if err := startHTTPServer(serverCtx); err != nil {
log.Fatalf("启动HTTP服务器失败: %v", err)
}
}()
}
}
}
}
func setupLogger() {
logConfigMutex.Lock()
defer logConfigMutex.Unlock()
if !cfg.Log.Enabled {
log.SetOutput(io.Discard)
log.Println("日志记录已禁用")
return
}
if cfg.Log.File == "" {
log.SetOutput(os.Stdout)
log.Println("日志记录已启用: 输出到标准输出")
return
}
logger := &lumberjack.Logger{
Filename: cfg.Log.File,
MaxSize: cfg.Log.MaxSizeMB,
MaxBackups: cfg.Log.MaxBackups,
MaxAge: cfg.Log.MaxAgeDays,
Compress: cfg.Log.Compress,
}
log.SetOutput(logger)
log.Printf("日志记录已启用: 输出到文件 %s", cfg.Log.File)
}
func startHTTPServer(ctx context.Context) error {
logConfigMutex.Lock()
addr := fmt.Sprintf(":%d", cfg.Server.Port)
logConfigMutex.Unlock()
fmt.Printf("监听端口: %d...\n", cfg.Server.Port)
srv := &http.Server{Addr: addr}
go func() {
if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
log.Printf("HTTP服务器启动失败: %v", err)
}
}()
<-ctx.Done()
shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
defer shutdownCancel()
if err := srv.Shutdown(shutdownCtx); err != nil {
log.Printf("HTTP服务器关闭失败: %v", err)
}
return nil
}
func handler(w http.ResponseWriter, r *http.Request) {
r.Header.Set("Connection", "close")
w.Header().Set("Connection", "close")
targetPath := getTargetPath(r)
targetURL := getTargetURL(r, targetPath)
proxyReq, err := createProxyRequest(r, targetURL)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
proxyResp, err := sendProxyRequest(proxyReq, r)
if err != nil {
http.Error(w, err.Error(), http.StatusBadGateway)
return
}
defer proxyResp.Body.Close()
if proxyResp.StatusCode == http.StatusMovedPermanently || proxyResp.StatusCode == http.StatusFound {
scheme := r.URL.Scheme
if scheme == "" {
if r.TLS != nil {
scheme = "https"
} else {
scheme = "http"
}
}
host := r.URL.Host
if host == "" {
host = r.Host
}
baseURL := fmt.Sprintf("%s://%s", scheme, host)
location := proxyResp.Header.Get("Location")
if location != "" {
location = baseURL + "/" + location
log.Printf("正在重定向到: %s", location)
w.Header().Set("Location", location)
}
w.WriteHeader(proxyResp.StatusCode)
return
}
logRequestAndResponse(r, targetURL, proxyResp)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
copyResponseToClientWithContext(ctx, w, proxyResp)
}
var client = &http.Client{
Timeout: 0,
Transport: &http.Transport{
DialContext: (&net.Dialer{
Timeout: 10 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).DialContext,
ResponseHeaderTimeout: 10 * time.Second,
TLSClientConfig: &tls.Config{},
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
MaxIdleConns: 100,
MaxIdleConnsPerHost: 10,
MaxConnsPerHost: 100,
},
CheckRedirect: func(req *http.Request, via []*http.Request) error {
const maxRedirects = 10
redirectCount := len(via)
if redirectCount >= maxRedirects {
return fmt.Errorf("超出最大重定向次数 (%d 次)", maxRedirects)
}
previousURL := via[redirectCount-1].URL
redirectURL, err := url.Parse(req.Response.Header.Get("Location"))
if err != nil {
return fmt.Errorf("无效的重定向 URL: %w", err)
}
targetURL := previousURL.ResolveReference(redirectURL)
req.URL = targetURL
log.Printf("从 %s 重定向到 %s", previousURL, targetURL)
return http.ErrUseLastResponse
},
}
func sendProxyRequest(proxyReq *http.Request, r *http.Request) (*http.Response, error) {
resp, err := client.Do(proxyReq)
if err != nil {
log.Printf("发送请求失败: %v", err)
return nil, err
}
return resp, nil
}
func getTargetPath(r *http.Request) string {
targetPath := r.URL.Path[1:]
query := r.URL.RawQuery
if query != "" {
targetPath += "?" + query
}
return targetPath
}
func getTargetURL(r *http.Request, targetPath string) string {
if strings.HasPrefix(targetPath, "http:/") {
targetPath = strings.TrimPrefix(targetPath, "http:/")
} else if strings.HasPrefix(targetPath, "https:/") {
targetPath = strings.TrimPrefix(targetPath, "https:/")
}
useHTTPS := strings.HasPrefix(r.URL.Path, "/https:/")
var targetURL string
if useHTTPS {
targetURL = "https://" + r.URL.Host + targetPath
} else {
targetURL = "http://" + r.URL.Host + targetPath
}
return targetURL
}
func createProxyRequest(r *http.Request, targetURL string) (*http.Request, error) {
proxyReq, err := http.NewRequest(r.Method, targetURL, nil)
if err != nil {
return nil, err
}
if r.Body != nil {
bodyCopy, err := io.ReadAll(r.Body)
if err != nil {
return nil, err
}
r.Body = io.NopCloser(bytes.NewBuffer(bodyCopy))
proxyReq.Body = io.NopCloser(bytes.NewBuffer(bodyCopy))
}
proxyReq.Header = make(http.Header)
copyHeader(proxyReq.Header, r.Header)
clientIP := strings.Split(r.RemoteAddr, ":")[0]
if prior, ok := proxyReq.Header["X-Forwarded-For"]; ok {
clientIP = prior[0] + ", " + clientIP
}
proxyReq.Header.Set("X-Forwarded-For", clientIP)
return proxyReq, nil
}
func logRequestAndResponse(r *http.Request, targetURL string, proxyResp *http.Response) {
remoteAddr := r.RemoteAddr
forwardedFor := r.Header.Get("X-Forwarded-For")
userAgent := r.Header.Get("User-Agent")
if forwardedFor != "" {
log.Printf("[X-Forwarded-For: %s] [%s] %s %s %s %d [User-Agent: %s]",
forwardedFor, remoteAddr, r.Method, targetURL, r.Proto, proxyResp.StatusCode, userAgent)
} else {
log.Printf("[%s] %s %s %s %d [User-Agent: %s]",
remoteAddr, r.Method, targetURL, r.Proto, proxyResp.StatusCode, userAgent)
}
}
func copyResponseToClientWithContext(ctx context.Context, w http.ResponseWriter, proxyResp *http.Response) {
defer func() {
if err := proxyResp.Body.Close(); err != nil {
log.Printf("关闭响应体错误: %v", err)
}
}()
copyHeader(w.Header(), proxyResp.Header)
w.WriteHeader(proxyResp.StatusCode)
buf := bufferPool.Get().([]byte)
defer bufferPool.Put(buf)
done := make(chan struct{})
go func() {
defer close(done)
if err := copyWithContext(ctx, w, proxyResp.Body, buf); err != nil {
handleCopyError(w, err, proxyResp)
}
}()
select {
case <-ctx.Done():
log.Println("客户端断开连接")
case <-done:
log.Println("响应成功完成")
}
}
func copyWithContext(ctx context.Context, dst io.Writer, src io.Reader, buf []byte) error {
for {
select {
case <-ctx.Done():
return ctx.Err()
default:
n, readErr := src.Read(buf)
if n > 0 {
written := 0
for written < n {
wn, writeErr := dst.Write(buf[written:n])
if writeErr != nil {
return fmt.Errorf("写入错误: %w", writeErr)
}
written += wn
}
}
if readErr != nil {
if errors.Is(readErr, io.EOF) {
return nil
}
return fmt.Errorf("读取错误: %w", readErr)
}
}
}
}
func handleCopyError(w http.ResponseWriter, err error, proxyResp *http.Response) {
if errors.Is(err, context.Canceled) {
log.Printf("传输被取消: %v, URL: %s", err, proxyResp.Request.URL.String())
} else if errors.Is(err, context.DeadlineExceeded) {
log.Printf("传输超时: %v, URL: %s", err, proxyResp.Request.URL.String())
} else {
log.Printf("传输错误: %v, URL: %s", err, proxyResp.Request.URL.String())
}
if w.Header().Get("Content-Length") == "" {
http.Error(w, "服务器错误", http.StatusInternalServerError)
}
}
func copyHeader(dst, src http.Header) {
for k, vv := range src {
for _, v := range vv {
dst.Add(k, v)
}
}
}
|