add express rate limiting

src/server/Server.ts

@@ -31,6 +31,8 @@ import { SecretManagerServiceClient } from "@google-cloud/secret-manager";
 import dotenv from "dotenv";
 import crypto from "crypto";
 dotenv.config();
+import rateLimit from "express-rate-limit";
+
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
@@ -51,6 +53,22 @@ let DISCORD_CLIENT_SECRET: string;
 app.use(express.static(path.join(__dirname, "../../out")));
 app.use(express.json());
 
+app.set("trust proxy", 2);
+app.use(
+  rateLimit({
+    windowMs: 1000, // 1 second
+    max: 20, // 20 requests per IP per second
+  }),
+);
+
+app.set("trust proxy", 2);
+app.use(
+  rateLimit({
+    windowMs: 1000, // 1 second
+    max: 20, // 20 requests per IP per second
+  }),
+);
+
 const gm = new GameManager(serverConfig);
 
 let lobbiesString = "";
@@ -208,6 +226,14 @@ app.get("/private_lobby/:id", (req, res) => {
   });
 });
 
+app.get("/debug-ip", (req, res) => {
+  res.send({
+    "x-forwarded-for": req.headers["x-forwarded-for"],
+    "real-ip": req.ip,
+    "raw-headers": req.rawHeaders,
+  });
+});
+
 app.get("*", function (req, res) {
   // SPA routing
   res.sendFile(path.join(__dirname, "../../out/index.html"));