From a77c6c3d9dea110611ea8a46c68e32c1ff9fd53f Mon Sep 17 00:00:00 2001
From: Evan <evanpelle@gmail.com>
Date: Tue, 13 Jan 2026 13:03:58 -0800
Subject: [PATCH] Inject server env vars into index.html, including instance id
 (#2888)

## Description:

Should fix the broken 1v1 on staging. The issue was that we had multiple
staging environments, and the matchmaker would often route a player to a
game on a different staging server, so the client couldn't find the
game.

So now each deployment has a unique id, and the matchmaker only connects
players & servers that have the same instance id.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan
---
 .vscode/settings.json               |  3 ++
 index.html                          |  6 +++
 package-lock.json                   |  8 +---
 package.json                        |  1 +
 src/client/JoinPrivateLobbyModal.ts | 28 ++---------
 src/client/Main.ts                  |  2 +
 src/client/Matchmaking.ts           |  4 +-
 src/server/Master.ts                | 74 +++++++++++++++++++++++------
 src/server/Worker.ts                |  1 +
 vite.config.ts                      | 40 ++++++----------
 10 files changed, 97 insertions(+), 70 deletions(-)
 create mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 000000000..c0c69aab9
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "html.validate.scripts": false
+}
diff --git a/index.html b/index.html
index a6e541a60..cad490b1c 100644
--- a/index.html
+++ b/index.html
@@ -56,6 +56,12 @@
     />
     <meta property="og:type" content="game" />
 
+    <!-- Injected from Server env -->
+    <script>
+      window.GIT_COMMIT = <%- gitCommit %>;
+      window.INSTANCE_ID = <%- instanceId %>;
+    </script>
+
     <!-- CrazyGames SDK -->
     <script
       src="https://sdk.crazygames.com/crazygames-sdk-v3.js"
diff --git a/package-lock.json b/package-lock.json
index f7eaad8e5..ae21c1e0f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -22,6 +22,7 @@
         "compression": "^1.8.1",
         "dompurify": "^3.1.7",
         "dotenv": "^16.5.0",
+        "ejs": "^3.1.10",
         "express": "^4.22.1",
         "express-rate-limit": "^7.5.0",
         "fastpriorityqueue": "^0.7.5",
@@ -5389,7 +5390,6 @@
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-1.0.2.tgz",
       "integrity": "sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/base64-js": {
@@ -5557,7 +5557,6 @@
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-2.0.2.tgz",
       "integrity": "sha512-Jt0vHyM+jmUBqojB7E1NIYadt0vI0Qxjxd2TErW94wDz+E2LAm5vKMXXwg6ZZBTHPuUlDgQHKXvjGBdfcF1ZDQ==",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^1.0.0"
@@ -7061,7 +7060,6 @@
       "version": "3.1.10",
       "resolved": "https://registry.npmjs.org/ejs/-/ejs-3.1.10.tgz",
       "integrity": "sha512-UeJmFfOrAQS8OJWPZ4qtgHyWExa088/MtK5UEyoJGFH67cDEXkZSviOiKRCZ4Xij0zxI3JECgYs3oKx+AizQBA==",
-      "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
         "jake": "^10.8.5"
@@ -7765,7 +7763,6 @@
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/filelist/-/filelist-1.0.4.tgz",
       "integrity": "sha512-w1cEuf3S+DrLCQL7ET6kz+gmlJdbq9J7yXCSjK/OZCPA+qEN1WyF4ZAf0YYJa4/shHJra2t/d/r8SV4Ji+x+8Q==",
-      "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
         "minimatch": "^5.0.1"
@@ -7775,7 +7772,6 @@
       "version": "5.1.6",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-5.1.6.tgz",
       "integrity": "sha512-lKwV/1brpG6mBUFHtb7NUmtABCb2WZZmm2wNiOA5hAb8VdCS4B3dtMWyvcoViccwAW/COERjXLt0zP1zXUN26g==",
-      "dev": true,
       "license": "ISC",
       "dependencies": {
         "brace-expansion": "^2.0.1"
@@ -8537,7 +8533,6 @@
       "version": "10.9.4",
       "resolved": "https://registry.npmjs.org/jake/-/jake-10.9.4.tgz",
       "integrity": "sha512-wpHYzhxiVQL+IV05BLE2Xn34zW1S223hvjtqk0+gsPrwd/8JNLXJgZZM/iPFsYc1xyphF+6M6EvdE5E9MBGkDA==",
-      "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
         "async": "^3.2.6",
@@ -10156,7 +10151,6 @@
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
       "integrity": "sha512-xceH2snhtb5M9liqDsmEw56le376mTZkEX/jEb/RxNFyegNul7eNslCXP9FDj/Lcu0X8KEyMceP2ntpaHrDEVA==",
-      "dev": true,
       "license": "ISC"
     },
     "node_modules/picomatch": {
diff --git a/package.json b/package.json
index b887b7eab..ee05b0b9f 100644
--- a/package.json
+++ b/package.json
@@ -104,6 +104,7 @@
     "compression": "^1.8.1",
     "dompurify": "^3.1.7",
     "dotenv": "^16.5.0",
+    "ejs": "^3.1.10",
     "express": "^4.22.1",
     "express-rate-limit": "^7.5.0",
     "fastpriorityqueue": "^0.7.5",
diff --git a/src/client/JoinPrivateLobbyModal.ts b/src/client/JoinPrivateLobbyModal.ts
index 833727bcf..c61342cc8 100644
--- a/src/client/JoinPrivateLobbyModal.ts
+++ b/src/client/JoinPrivateLobbyModal.ts
@@ -524,22 +524,12 @@ export class JoinPrivateLobbyModal extends BaseModal {
   private async checkArchivedGame(
     lobbyId: string,
   ): Promise<"success" | "not_found" | "version_mismatch" | "error"> {
-    const archivePromise = fetch(`${getApiBase()}/game/${lobbyId}`, {
+    const archiveResponse = await fetch(`${getApiBase()}/game/${lobbyId}`, {
       method: "GET",
       headers: {
         "Content-Type": "application/json",
       },
     });
-    const gitCommitPromise = fetch(`/commit.txt`, {
-      method: "GET",
-      headers: { "Content-Type": "application/json" },
-      cache: "no-cache",
-    });
-
-    const [archiveResponse, gitCommitResponse] = await Promise.all([
-      archivePromise,
-      gitCommitPromise,
-    ]);
 
     if (archiveResponse.status === 404) {
       return "not_found";
@@ -554,19 +544,11 @@ export class JoinPrivateLobbyModal extends BaseModal {
       return "version_mismatch";
     }
 
-    let myGitCommit = "";
-    if (gitCommitResponse.status === 404) {
-      // commit.txt is not found when running locally
-      myGitCommit = "DEV";
-    } else if (gitCommitResponse.status === 200) {
-      myGitCommit = (await gitCommitResponse.text()).trim();
-    } else {
-      console.error("Error getting git commit:", gitCommitResponse.status);
-      return "error";
-    }
-
     // Allow DEV to join games created with a different version for debugging.
-    if (myGitCommit !== "DEV" && parsed.data.gitCommit !== myGitCommit) {
+    if (
+      window.GIT_COMMIT !== "DEV" &&
+      parsed.data.gitCommit !== window.GIT_COMMIT
+    ) {
       const safeLobbyId = this.sanitizeForLog(lobbyId);
       console.warn(
         `Git commit hash mismatch for game ${safeLobbyId}`,
diff --git a/src/client/Main.ts b/src/client/Main.ts
index 1b4a86cb7..732e0f37f 100644
--- a/src/client/Main.ts
+++ b/src/client/Main.ts
@@ -160,6 +160,8 @@ function updateAccountNavButton(userMeResponse: UserMeResponse | false) {
 
 declare global {
   interface Window {
+    GIT_COMMIT: string;
+    INSTANCE_ID: string;
     turnstile: any;
     enableAds: boolean;
     PageOS: {
diff --git a/src/client/Matchmaking.ts b/src/client/Matchmaking.ts
index e3a9b4459..4f3f55933 100644
--- a/src/client/Matchmaking.ts
+++ b/src/client/Matchmaking.ts
@@ -120,7 +120,9 @@ export class MatchmakingModal extends BaseModal {
   private async connect() {
     const config = await getServerConfigFromClient();
 
-    this.socket = new WebSocket(`${config.jwtIssuer()}/matchmaking/join`);
+    this.socket = new WebSocket(
+      `${config.jwtIssuer()}/matchmaking/join?instance_id=${window.INSTANCE_ID}`,
+    );
     this.socket.onopen = async () => {
       console.log("Connected to matchmaking server");
       setTimeout(() => {
diff --git a/src/server/Master.ts b/src/server/Master.ts
index 441135f04..298b6b247 100644
--- a/src/server/Master.ts
+++ b/src/server/Master.ts
@@ -1,11 +1,14 @@
 import cluster from "cluster";
 import crypto from "crypto";
+import ejs from "ejs";
 import express from "express";
 import rateLimit from "express-rate-limit";
+import fs from "fs/promises";
 import http from "http";
 import path from "path";
 import { fileURLToPath } from "url";
 import { WebSocket, WebSocketServer } from "ws";
+import { GameEnv } from "../core/configuration/Config";
 import { getServerConfigFromServer } from "../core/configuration/ConfigLoader";
 import { GameInfo } from "../core/Schemas";
 import { generateID } from "../core/Util";
@@ -23,23 +26,29 @@ const log = logger.child({ comp: "m" });
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
+
 app.use(express.json());
+
+// Middleware to handle HTML files with EJS templating
+app.use(async (req, res, next) => {
+  if (req.path === "/") {
+    try {
+      await renderHtml(res, path.join(__dirname, "../../static/index.html"));
+    } catch (error) {
+      log.error("Error rendering index.html:", error);
+      res.status(500).send("Internal Server Error");
+    }
+  } else {
+    next();
+  }
+});
+
 app.use(
   express.static(path.join(__dirname, "../../static"), {
     maxAge: "1y", // Set max-age to 1 year for all static assets
     setHeaders: (res, path) => {
       // You can conditionally set different cache times based on file types
-      if (path.endsWith(".html")) {
-        // Set HTML files to no-cache to ensure Express doesn't send 304s
-        res.setHeader(
-          "Cache-Control",
-          "no-store, no-cache, must-revalidate, proxy-revalidate",
-        );
-        res.setHeader("Pragma", "no-cache");
-        res.setHeader("Expires", "0");
-        // Prevent conditional requests
-        res.setHeader("ETag", "");
-      } else if (path.match(/\.(js|css|svg)$/)) {
+      if (path.match(/\.(js|css|svg)$/)) {
         // JS, CSS, SVG get long cache with immutable
         res.setHeader("Cache-Control", "public, max-age=31536000, immutable");
       } else if (path.match(/\.(bin|dat|exe|dll|so|dylib)$/)) {
@@ -50,7 +59,6 @@ app.use(
     },
   }),
 );
-app.use(express.json());
 
 app.set("trust proxy", 3);
 app.use(
@@ -133,11 +141,20 @@ export async function startMaster() {
   const ADMIN_TOKEN = crypto.randomBytes(16).toString("hex");
   process.env.ADMIN_TOKEN = ADMIN_TOKEN;
 
+  const INSTANCE_ID =
+    config.env() === GameEnv.Dev
+      ? "DEV_ID"
+      : crypto.randomBytes(4).toString("hex");
+  process.env.INSTANCE_ID = INSTANCE_ID;
+
+  log.info(`Instance ID: ${INSTANCE_ID}`);
+
   // Fork workers
   for (let i = 0; i < config.numWorkers(); i++) {
     const worker = cluster.fork({
       WORKER_ID: i,
       ADMIN_TOKEN,
+      INSTANCE_ID,
     });
 
     log.info(`Started worker ${i} (PID: ${worker.process.pid})`);
@@ -190,6 +207,7 @@ export async function startMaster() {
     const newWorker = cluster.fork({
       WORKER_ID: workerId,
       ADMIN_TOKEN,
+      INSTANCE_ID,
     });
 
     log.info(
@@ -321,6 +339,34 @@ async function schedulePublicGame(playlist: MapPlaylist) {
 }
 
 // SPA fallback route
-app.get("*", function (req, res) {
-  res.sendFile(path.join(__dirname, "../../static/index.html"));
+app.get("*", async function (_req, res) {
+  try {
+    const htmlPath = path.join(__dirname, "../../static/index.html");
+    await renderHtml(res, htmlPath);
+  } catch (error) {
+    log.error("Error rendering SPA fallback:", error);
+    res.status(500).send("Internal Server Error");
+  }
 });
+
+// Helper function to render HTML with EJS templating
+async function renderHtml(
+  res: express.Response,
+  htmlPath: string,
+): Promise<void> {
+  const htmlContent = await fs.readFile(htmlPath, "utf-8");
+  const rendered = ejs.render(htmlContent, {
+    gitCommit: JSON.stringify(process.env.GIT_COMMIT ?? "undefined"),
+    instanceId: JSON.stringify(process.env.INSTANCE_ID ?? "undefined"),
+  });
+
+  res.setHeader(
+    "Cache-Control",
+    "no-store, no-cache, must-revalidate, proxy-revalidate",
+  );
+  res.setHeader("Pragma", "no-cache");
+  res.setHeader("Expires", "0");
+  res.setHeader("ETag", "");
+  res.setHeader("Content-Type", "text/html");
+  res.send(rendered);
+}
diff --git a/src/server/Worker.ts b/src/server/Worker.ts
index 780f76041..d08bef129 100644
--- a/src/server/Worker.ts
+++ b/src/server/Worker.ts
@@ -479,6 +479,7 @@ async function pollLobby(gm: GameManager) {
         id: workerId,
         gameId: gameId,
         ccu: gm.activeClients(),
+        instanceId: process.env.INSTANCE_ID,
       }),
       signal: controller.signal,
     });
diff --git a/vite.config.ts b/vite.config.ts
index 7c4d772c0..0153c4bd9 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,5 +1,4 @@
 import tailwindcss from "@tailwindcss/vite";
-import { execSync } from "child_process";
 import path from "path";
 import { fileURLToPath } from "url";
 import { defineConfig, loadEnv } from "vite";
@@ -11,19 +10,6 @@ import tsconfigPaths from "vite-tsconfig-paths";
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
-let gitCommit = process.env.GIT_COMMIT;
-
-if (!gitCommit) {
-  try {
-    gitCommit = execSync("git rev-parse HEAD").toString().trim();
-  } catch (error) {
-    if (process.env.NODE_ENV !== "production") {
-      console.warn("Unable to determine git commit:", error.message);
-    }
-    gitCommit = "unknown";
-  }
-}
-
 export default defineConfig(({ mode }) => {
   const env = loadEnv(mode, process.cwd(), "");
   const isProduction = mode === "production";
@@ -50,16 +36,21 @@ export default defineConfig(({ mode }) => {
 
     plugins: [
       tsconfigPaths(),
-      createHtmlPlugin({
-        minify: isProduction,
-        entry: "/src/client/Main.ts",
-        template: "index.html",
-        inject: {
-          data: {
-            // In case we need to inject variables into HTML
-          },
-        },
-      }),
+      ...(isProduction
+        ? []
+        : [
+            createHtmlPlugin({
+              minify: false,
+              entry: "/src/client/Main.ts",
+              template: "index.html",
+              inject: {
+                data: {
+                  gitCommit: JSON.stringify("DEV"),
+                  instanceId: JSON.stringify("DEV_ID"),
+                },
+              },
+            }),
+          ]),
       viteStaticCopy({
         targets: [
           {
@@ -76,7 +67,6 @@ export default defineConfig(({ mode }) => {
         isProduction ? "" : "localhost:3000",
       ),
       "process.env.GAME_ENV": JSON.stringify(isProduction ? "prod" : "dev"),
-      "process.env.GIT_COMMIT": JSON.stringify(gitCommit),
       "process.env.STRIPE_PUBLISHABLE_KEY": JSON.stringify(
         env.STRIPE_PUBLISHABLE_KEY,
       ),