日志http.ResponseWriter内容

Question

前提：我发现了一个类似的问题，但在我的情况下不起作用，所以请不要将其标记为重复。

我在Go中有一个HTTP服务器，我创建了一个中间件来记录请求和响应时间，我也想记录响应。

我在包log下的一个名为HTTPRequest的函数中使用了httputil.DumpRequest。如何从w http.ResponseWriter中正确获取响应主体、状态和标头，并将它们与其他数据一起记录？

我的问题是：我想截获响应标头、状态和正文，并将其与请求和响应时间一起记录

这是代码：

log "core/logger"
...
func RequestLoggerMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
defer func() {
log.Info(
fmt.Sprintf(
"[Request: %s] [Execution time: %v] [Response: %s]",
log.HTTPRequest(r),
time.Since(start),
// RESPONSE DATA HERE !!!!!!!
))
}()
next.ServeHTTP(w, r)
})
}

Answer 1

感谢@Sivachandran的回复。它几乎是完美的，只是由于指针的原因，它没有实现http.ResponseWriter。

为了完整起见，我在这里发布了正确的解决方案代码，因为即使这个问题被打了负面分数，也不容易找到任何文档。

Stackoverflow是一个交换问题的好地方，在我看来，这是一个非常好和困难的问题，对于一个中级Golang程序员来说，所以它根本不应该被负分！

这就是解决方案，享受：

// RequestLoggerMiddleware is the middleware layer to log all the HTTP requests
func RequestLoggerMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
rww := NewResponseWriterWrapper(w)
w.Header()
defer func() {
log.Info(
fmt.Sprintf(
"[Request: %s] [Execution time: %v] [Response: %s]",
log.HTTPRequest(r),
time.Since(start),
rww.String(),
))
}()
next.ServeHTTP(rww, r)
})
}
// ResponseWriterWrapper struct is used to log the response
type ResponseWriterWrapper struct {
w          *http.ResponseWriter
body       *bytes.Buffer
statusCode *int
}
// NewResponseWriterWrapper static function creates a wrapper for the http.ResponseWriter
func NewResponseWriterWrapper(w http.ResponseWriter) ResponseWriterWrapper {
var buf bytes.Buffer
var statusCode int = 200
return ResponseWriterWrapper{
w:          &w,
body:       &buf,
statusCode: &statusCode,
}
}
func (rww ResponseWriterWrapper) Write(buf []byte) (int, error) {
rww.body.Write(buf)
return (*rww.w).Write(buf)
}
// Header function overwrites the http.ResponseWriter Header() function
func (rww ResponseWriterWrapper) Header() http.Header {
return (*rww.w).Header()
}
// WriteHeader function overwrites the http.ResponseWriter WriteHeader() function
func (rww ResponseWriterWrapper) WriteHeader(statusCode int) {
(*rww.statusCode) = statusCode
(*rww.w).WriteHeader(statusCode)
}
func (rww ResponseWriterWrapper) String() string {
var buf bytes.Buffer
buf.WriteString("Response:")
buf.WriteString("Headers:")
for k, v := range (*rww.w).Header() {
buf.WriteString(fmt.Sprintf("%s: %v", k, v))
}
buf.WriteString(fmt.Sprintf(" Status Code: %d", *(rww.statusCode)))
buf.WriteString("Body")
buf.WriteString(rww.body.String())
return buf.String()
}

Answer 2

您需要包装ResponseWriter来捕获响应数据。

type ResponseWriterWrapper struct {
w           http.ResponseWriter
body        bytes.Buffer
statusCode  int
}
func (i *ResponseWriterWrapper) Write(buf []byte) (int, error) {
i.body.Write(buf)
return i.w.Write(buf)
}
func (i *ResponseWriterWrapper) WriteHeader(statusCode int) {
i.statusCode = statusCode
i.w.WriteHeader(statusCode)
}
func (i *ResponseWriterWrapper) String() {
var buf bytes.Buffer
buf.WriteString("Response:")
buf.WriteString("Headers:")
for k, v := range i.w.Header() {
buf.WriteString(fmt.Sprintf("%s: %v", k, v))
}
buf.WriteString(fmt.Sprintf("Status Code: %d", i.statusCode))
buf.WriteString("Body")
buf.WriteString(i.body.String())
}

将包装器传递给ServeHTTP并记录捕获的响应数据。

func RequestLoggerMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
rww := ResponseWriterWrapper{ w: w }
defer func() {
log.Info(
fmt.Sprintf(
"[Request: %s] [Execution time: %v] [Response: %s]",
log.HTTPRequest(r),
time.Since(start),
log.Info(rww.String())
))
}()
next.ServeHTTP(rww, r)
})
}