changed log to combined log format

main.go

@@ -1,15 +1,17 @@
 package main
 
 import (
+	"crypto/rand"
+	"encoding/json"
+	"html/template"
+	"log"
+	"net"
+	"net/http"
 	"os"
 	"strconv"
 	"strings"
 	"sync"
-	"crypto/rand"
-	"html/template"
-	"log"
-	"net/http"
-	"encoding/json"
+	"time"
 )
 
 const (
@@ -25,6 +27,43 @@ var (
 	mu          sync.Mutex
 )
 
+type responseWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func (rw *responseWriter) WriteHeader(code int) {
+	rw.statusCode = code
+	rw.ResponseWriter.WriteHeader(code)
+}
+
+func newResponseWriter(w http.ResponseWriter) *responseWriter {
+	return &responseWriter{w, http.StatusOK} // Default 200 OK
+}
+
+func LoggingMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		rw := newResponseWriter(w)
+		next.ServeHTTP(rw, r)
+		duration := time.Since(start)
+		clientIP := getClientIP(r)
+		userAgent := r.UserAgent()
+		// Format: IP - - [Datum] "Method Path Proto" Status Duration User-Agent
+		// "Combined Log Format"
+		log.Printf("%s - - [%s] \"%s %s %s\" %d %v\n",
+			clientIP,
+			time.Now().Format("02/Jan/2006:15:04:05 -0700"),
+			r.Method,
+			r.URL.Path,
+			r.Proto,
+			rw.statusCode,
+			duration,
+			userAgent,
+		)
+	})
+}
+
 func getClientIP(r *http.Request) string {
 	// 1. Prüfe den X-Forwarded-For Header (Standard für Proxies)
 	xForwardedFor := r.Header.Get("X-Forwarded-For")
@@ -99,7 +138,9 @@ func loadTemplates() {
 }
 
 func generatePassword() string {
-	if debug { log.Printf("called generatePassword\n") }
+	if debug {
+		log.Printf("called generatePassword\n")
+	}
 	password := make([]byte, passwordLength)
 	_, err := rand.Read(password)
 	if err != nil {
@@ -113,9 +154,9 @@ func generatePassword() string {
 }
 
 func passwordHandler(w http.ResponseWriter, r *http.Request) {
-    clientIP := getClientIP(r)
-    log.Printf("passwordHandler aufrerufen von IP: %s\n", clientIP)
-    if debug { log.Printf("called passwordHandler\n") }
+	if debug {
+		log.Printf("called passwordHandler\n")
+	}
 	password := generatePassword()
 	currentCount := GetPasswordCount()
 	response := map[string]interface{}{
@@ -132,18 +173,18 @@ func passwordHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func passwordAPIHandler(w http.ResponseWriter, r *http.Request) {
-	clientIP := getClientIP(r)
-	log.Printf("passwordAPIHandler aufrerufen von IP: %s\n", clientIP)
-	if debug { log.Printf("called passwordHandler\n") }
+	if debug {
+		log.Printf("called passwordHandler\n")
+	}
 	password := generatePassword()
 	w.Header().Set("Content-Type", "text/plain")
 	w.Write([]byte(password))
 }
 
 func indexHandler(w http.ResponseWriter, r *http.Request) {
-	clientIP := getClientIP(r)
-	log.Printf("indexHandler aufrerufen von IP: %s\n", clientIP)
-	if debug { log.Printf("call indexHandler: Request %s %s\n", r.Method, r.URL) }
+	if debug {
+		log.Printf("call indexHandler: Request %s %s\n", r.Method, r.URL)
+	}
 	password := generatePassword()
 	//password := "load..."
 	data := struct {
@@ -151,7 +192,9 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 	}{
 		Password: password,
 	}
-	if debug { log.Printf("prepare template for index\n") }
+	if debug {
+		log.Printf("prepare template for index\n")
+	}
 	err := templates["index.html"].ExecuteTemplate(w, "base.html", data)
 	if err != nil {
 		log.Printf("Fehler beim Rendern des Templates: %v", err)
@@ -160,9 +203,9 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func helpHandler(w http.ResponseWriter, r *http.Request) {
-	clientIP := getClientIP(r)
-	log.Printf("helpHandler aufrerufen von IP: %s\n", clientIP)
-	if debug { log.Printf("call helpHandler\n") }
+	if debug {
+		log.Printf("call helpHandler\n")
+	}
 	err := templates["help.html"].ExecuteTemplate(w, "base.html", nil)
 	if err != nil {
 		log.Printf("Fehler beim Rendern des Templates: %v", err)
@@ -172,14 +215,19 @@ func helpHandler(w http.ResponseWriter, r *http.Request) {
 
 func main() {
 	loadTemplates()
-	fs := http.FileServer(http.Dir("static"))
-	http.Handle("/static/", http.StripPrefix("/static/", fs))
+	mux := http.NewServeMux()
 
-	http.HandleFunc("/", indexHandler)
-	http.HandleFunc("/api/password", passwordAPIHandler)
-	http.HandleFunc("/json/password", passwordHandler)
-	http.HandleFunc("/help", helpHandler)
+	fs := http.FileServer(http.Dir("static"))
+	mux.Handle("/static/", http.StripPrefix("/static/", fs))
+
+	mux.HandleFunc("/", indexHandler)
+	mux.HandleFunc("/api/password", passwordAPIHandler)
+	mux.HandleFunc("/json/password", passwordHandler)
+	mux.HandleFunc("/help", helpHandler)
+
+	loggingRouter := LoggingMiddleware(mux)
 
 	log.Println("Server läuft auf http://localhost:8080")
-	log.Fatal(http.ListenAndServe(":8080", nil))
+
+	log.Fatal(http.ListenAndServe(":8080", loggingRouter))
 }