fixed log printf

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"
+	"time"
-	"html/template"
-	"log"
-	"net/http"
-	"encoding/json"
 )
 
 const (
@@ -25,6 +27,65 @@ 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 \"%s\"\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")
+	if xForwardedFor != "" {
+		// Der Header kann eine Liste von IPs sein (Client, Proxy1, Proxy2)
+		// Die erste IP in der Liste ist die echte Client-IP
+		ips := strings.Split(xForwardedFor, ",")
+		return strings.TrimSpace(ips[0])
+	}
+
+	// 2. Fallback auf X-Real-IP (oft von Traefik/Nginx gesetzt)
+	xRealIP := r.Header.Get("X-Real-IP")
+	if xRealIP != "" {
+		return xRealIP
+	}
+
+	// 3. Letzter Ausweg: Die direkte IP (wird in deinem Fall die Traefik-IP sein)
+	// RemoteAddr enthält oft auch den Port (z.B. "127.0.0.1:1234")
+	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
+	return ip
+}
+
 // Diese Funktion wird nur intern aufgerufen, wenn der Mutex bereits gesperrt ist
 func getCount() int {
 	data, err := os.ReadFile(counterFile)
@@ -77,7 +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 {
@@ -91,7 +154,9 @@ func generatePassword() string {
 }
 
 func passwordHandler(w http.ResponseWriter, r *http.Request) {
-    if debug { log.Printf("called passwordHandler\n") }
+	if debug {
+		log.Printf("called passwordHandler\n")
+	}
 	password := generatePassword()
 	currentCount := GetPasswordCount()
 	response := map[string]interface{}{
@@ -108,14 +173,18 @@ func passwordHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func passwordAPIHandler(w http.ResponseWriter, r *http.Request) {
-	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) {
-	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 {
@@ -123,7 +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)
@@ -132,7 +203,9 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func helpHandler(w http.ResponseWriter, r *http.Request) {
-	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)
@@ -142,14 +215,19 @@ func helpHandler(w http.ResponseWriter, r *http.Request) {
 
 func main() {
 	loadTemplates()
-	fs := http.FileServer(http.Dir("static"))
+	mux := http.NewServeMux()
-	http.Handle("/static/", http.StripPrefix("/static/", fs))
 
-	http.HandleFunc("/", indexHandler)
+	fs := http.FileServer(http.Dir("static"))
-	http.HandleFunc("/api/password", passwordAPIHandler)
+	mux.Handle("/static/", http.StripPrefix("/static/", fs))
-	http.HandleFunc("/json/password", passwordHandler)
+
-	http.HandleFunc("/help", helpHandler)
+	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))
 }