dnote/pkg/server/handlers/logging.go

package handlers

import (
	"fmt"
	"net/http"
	"time"

	"github.com/dnote/dnote/pkg/server/log"
)

// logResponseWriter wraps http.ResponseWriter to expose HTTP status code for logging.
// The optional interfaces of http.ResponseWriter are lost because of the wrapping, and
// such interfaces should be implemented if needed. (i.e. http.Pusher, http.Flusher, etc.)
type logResponseWriter struct {
	http.ResponseWriter
	statusCode int
}

func (w *logResponseWriter) WriteHeader(code int) {
	w.statusCode = code
	w.ResponseWriter.WriteHeader(code)
}

// Logging is a logging middleware
func Logging(inner http.Handler) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()

		lw := logResponseWriter{w, http.StatusOK}
		inner.ServeHTTP(&lw, r)

		log.WithFields(log.Fields{
			"origin":     r.Header.Get("Origin"),
			"remoteAddr": lookupIP(r),
			"uri":        r.RequestURI,
			"statusCode": lw.statusCode,
			"method":     r.Method,
			"duration":   fmt.Sprintf("%dms", time.Since(start)/1000000),
			"userAgent":  r.Header.Get("User-Agent"),
		}).Info("incoming request")
	}
}