add ch13

ch13/2/ch13_2.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+	"log/slog"
+	"net"
+	"net/http"
+	"time"
+)
+
+type TimeHandler struct{}
+
+func (th TimeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	w.Write([]byte(time.Now().Format(time.RFC3339)))
+}
+
+func RequestToIP(r *http.Request) string {
+	ip, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		slog.Error(fmt.Sprintf("Wrong format of address: %q", r.RemoteAddr))
+	}
+	return ip
+}
+
+func RequestIPHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		slog.Info(RequestToIP(r))
+		h.ServeHTTP(w, r)
+	})
+}
+
+func main() {
+	server := http.Server{
+		Addr:         ":10100",
+		ReadTimeout:  30 * time.Second,
+		WriteTimeout: 90 * time.Second,
+		IdleTimeout:  120 * time.Second,
+		Handler:      RequestIPHandler(TimeHandler{}),
+	}
+	err := server.ListenAndServe()
+	if err != nil {
+		if err != http.ErrServerClosed {
+			panic(err)
+		}
+	}
+}