add log middleware (just for testing)

backend/middleware.go

@@ -1,8 +1,14 @@
 package main
 
 import (
+	"bytes"
+	"fmt"
+	"io"
 	"net/http"
 	"os"
+	"time"
+
+	"crypto/subtle"
 )
 
 func authMiddleware(next http.Handler) http.Handler {
@@ -18,7 +24,7 @@ func authMiddleware(next http.Handler) http.Handler {
 
 		expectedHeader := "Bearer " + expectedKey
 
-		if authHeader != expectedHeader {
+		if subtle.ConstantTimeCompare([]byte(authHeader), []byte(expectedHeader)) != 1 {
 			http.Error(w, "unauthorized", http.StatusUnauthorized)
 			return
 		}
@@ -26,3 +32,32 @@ func authMiddleware(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+func logMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		reqMethod := r.Method
+		reqUrl := r.URL.String()
+		reqIp := r.RemoteAddr
+		reqHeaderContentType := r.Header.Get("Content-Type")
+		defer r.Body.Close()
+		bodyBytes, err := io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, "[log] Failed to read body", http.StatusBadRequest)
+			return
+		}
+
+		fmt.Printf("\n[%s] %s request on %s\n", reqIp, reqMethod, reqUrl)
+		fmt.Println("Timestamp (UTC):      " + time.Now().UTC().String())
+		fmt.Println("Header Content-Type:  " + reqHeaderContentType)
+		if len(bodyBytes) == 0 {
+			fmt.Println("Body:                 <empty>")
+		} else {
+			fmt.Println("Body:                 " + string(bodyBytes))
+		}
+
+		// restore the request body for later
+		r.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
+
+		next.ServeHTTP(w, r)
+	})
+}