package middleware import ( "bytes" "fmt" "github.com/gin-gonic/gin" "github.com/sirupsen/logrus" "io" "io/ioutil" "math" "net/http" "os" "strings" "time" ) // Middleware based on https://github.com/toorop/gin-logrus/blob/master/logger.go // Body recording based on // - https://github.com/gin-gonic/gin/issues/1363 // - https://stackoverflow.com/questions/38501325/how-to-log-response-body-in-gin // 2016-09-27 09:38:21.541541811 +0200 CEST // 127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] // "GET /apache_pb.gif HTTP/1.0" 200 2326 // "http://www.example.com/start.html" // "Mozilla/4.08 [en] (Win98; I ;Nav)" var timeFormat = "02/Jan/2006:15:04:05 -0700" // Logger is the logrus logger handler func LoggerMiddleware(logger *logrus.Entry) gin.HandlerFunc { hostname, err := os.Hostname() if err != nil { hostname = "unknown" } return func(c *gin.Context) { //clone the request body reader. var reqBody string if c.Request.Body != nil { buf, _ := ioutil.ReadAll(c.Request.Body) reqBodyReader1 := ioutil.NopCloser(bytes.NewBuffer(buf)) reqBodyReader2 := ioutil.NopCloser(bytes.NewBuffer(buf)) //We have to create a new Buffer, because reqBodyReader1 will be read. c.Request.Body = reqBodyReader2 reqBody = readBody(reqBodyReader1) } // other handler can change c.Path so: path := c.Request.URL.Path blw := &responseBodyLogWriter{body: &bytes.Buffer{}, ResponseWriter: c.Writer} c.Writer = blw c.Set("LOGGER", logger) start := time.Now() c.Next() stop := time.Since(start) latency := int(math.Ceil(float64(stop.Nanoseconds()) / 1000000.0)) statusCode := c.Writer.Status() clientIP := c.ClientIP() clientUserAgent := c.Request.UserAgent() referer := c.Request.Referer() respLength := c.Writer.Size() if respLength < 0 { respLength = 0 } entry := logger.WithFields(logrus.Fields{ "hostname": hostname, "statusCode": statusCode, "latency": latency, // time to process "clientIP": clientIP, "method": c.Request.Method, "path": path, "referer": referer, "respLength": respLength, "userAgent": clientUserAgent, }) if len(c.Errors) > 0 { entry.Error(c.Errors.ByType(gin.ErrorTypePrivate).String()) } else { msg := fmt.Sprintf("%s - %s [%s] \"%s %s\" %d %d \"%s\" \"%s\" (%dms)", clientIP, hostname, time.Now().Format(timeFormat), c.Request.Method, path, statusCode, respLength, referer, clientUserAgent, latency) if statusCode >= http.StatusInternalServerError { entry.Error(msg) } else if statusCode >= http.StatusBadRequest { entry.Warn(msg) } else { entry.Info(msg) } } if strings.Contains(path, "/api/") { //only debug log request/response from api endpoint. if len(reqBody) > 0 { entry.WithField("bodyType", "request").Debugln(reqBody) // Print request body } entry.WithField("bodyType", "response").Debugln(blw.body.String()) } } } // Response Logging type responseBodyLogWriter struct { gin.ResponseWriter body *bytes.Buffer } func (w responseBodyLogWriter) Write(b []byte) (int, error) { w.body.Write(b) return w.ResponseWriter.Write(b) } // Request Logging func readBody(reader io.Reader) string { buf := new(bytes.Buffer) buf.ReadFrom(reader) s := buf.String() return s }