From dc0b3f2eb29ee70311bba8e0c75bedf214acaccd Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Mon, 22 Dec 2025 23:44:29 +0800
Subject: [PATCH] Fix QlBaseUrl: use URL rewrite for base path support (#2876)

* Initial plan

* Add QlBaseUrl support to backend routes

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Fix whitelist check to use base-URL-aware paths

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Update websocket and frontend to support base URL

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Address code review feedback: fix JWT regex and path construction

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Fix path construction: use req.path directly for whitelist check

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Add clarifying comments and improve code readability

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Apply code review suggestions: improve clarity and simplify logic

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

* Simplify baseUrl implementation using URL rewrite

Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: whyour <22700758+whyour@users.noreply.github.com>
---
 back/config/index.ts    | 14 ++++++++++++++
 back/loaders/express.ts |  7 +++++++
 2 files changed, 21 insertions(+)

diff --git a/back/config/index.ts b/back/config/index.ts
index 76eb08c6..f7c7a54c 100644
--- a/back/config/index.ts
+++ b/back/config/index.ts
@@ -64,6 +64,19 @@ if (!process.env.QL_DIR) {
 
 const lastVersionFile = `https://qn.whyour.cn/version.yaml`;
 
+// Get and normalize QlBaseUrl
+let baseUrl = process.env.QlBaseUrl || '';
+if (baseUrl) {
+  // Ensure it starts with /
+  if (!baseUrl.startsWith('/')) {
+    baseUrl = `/${baseUrl}`;
+  }
+  // Remove trailing slash for consistency in route definitions
+  if (baseUrl.endsWith('/')) {
+    baseUrl = baseUrl.slice(0, -1);
+  }
+}
+
 const rootPath = process.env.QL_DIR as string;
 const envFound = dotenv.config({ path: path.join(rootPath, '.env') });
 
@@ -116,6 +129,7 @@ if (envFound.error) {
 export default {
   ...config,
   jwt: config.jwt,
+  baseUrl,
   rootPath,
   tmpPath,
   dataPath,
diff --git a/back/loaders/express.ts b/back/loaders/express.ts
index f7d4a65b..63065a21 100644
--- a/back/loaders/express.ts
+++ b/back/loaders/express.ts
@@ -15,6 +15,13 @@ import path from 'path';
 export default ({ app }: { app: Application }) => {
   app.set('trust proxy', 'loopback');
   app.use(cors());
+  
+  // Rewrite URLs to strip baseUrl prefix if configured
+  // This allows the rest of the app to work without baseUrl awareness
+  if (config.baseUrl) {
+    app.use(rewrite(`${config.baseUrl}/*`, '/$1'));
+  }
+  
   app.get(`${config.api.prefix}/env.js`, serveEnv);
   app.use(`${config.api.prefix}/static`, express.static(config.uploadPath));