Support sub-path deployment for Docker and Vite

.env.sample

@@ -1 +1,3 @@
-VITE_BACKEND_URL=http://backend.com
+VITE_BACKEND_URL=http://backend.com
+# Uncomment to build for a sub-path (defaults to /)
+# VITE_BASE_PATH=/drawdb

Dockerfile

@@ -5,11 +5,14 @@ COPY package*.json ./
 RUN npm ci
 COPY . .
 ENV NODE_OPTIONS="--max-old-space-size=4096"
+ENV VITE_BASE_PATH=__BASE_PATH__
 RUN npm run build
 
 # Stage 2: Setup the Nginx Server to serve the app
 FROM docker.io/library/nginx:stable-alpine3.17 AS production
 COPY --from=build /app/dist /usr/share/nginx/html
-RUN echo 'server { listen 80; server_name _; root /usr/share/nginx/html;  location / { try_files $uri /index.html; } }' > /etc/nginx/conf.d/default.conf
+COPY docker-entrypoint.sh /docker-entrypoint.sh
+RUN chmod +x /docker-entrypoint.sh && rm /etc/nginx/conf.d/default.conf
 EXPOSE 80
+ENTRYPOINT ["/docker-entrypoint.sh"]
 CMD ["nginx", "-g", "daemon off;"]

README.md

@@ -64,4 +64,15 @@ docker build -t drawdb .
 docker run -p 3000:80 drawdb
 ```
 
+To serve the app from a sub-path, set the deployment context at runtime. Replace `/drawdb` with your desired base path.
+
+```bash
+docker run -p 3000:80 -e DRAWDB_BASE_PATH=/drawdb drawdb
+```
+
+### Deployment Context
+
+- `VITE_BASE_PATH` (build-time) controls the base URL when building outside of Docker. Set it before running `npm run build`, for example `VITE_BASE_PATH=/drawdb npm run build`. The default `/` serves the app at the domain root. The Docker image sets a placeholder during build so you can usually leave this unset.
+- `DRAWDB_BASE_PATH` (runtime, Docker only) updates the pre-built assets and Nginx routing when the container starts. It must match the path used at build time (default `/`). Provide a relative path such as `/drawdb`.
+
 If you want to enable sharing, set up the [server](https://github.com/drawdb-io/drawdb-server) and environment variables according to `.env.sample`. This is optional unless you need to share files..

docker-entrypoint.sh

@@ -0,0 +1,82 @@
+#!/bin/sh
+set -eu
+
+CONTENT_DIR="/usr/share/nginx/html"
+# Allow overriding the served base path at runtime (default /)
+BASE_PATH="${DRAWDB_BASE_PATH:-/}"
+
+if [ -z "$BASE_PATH" ]; then
+  BASE_PATH="/"
+fi
+
+# Reject absolute URLs; only relative paths are supported
+case "$BASE_PATH" in
+  http://*|https://*)
+    echo "DRAWDB_BASE_PATH must be a relative path (e.g. /drawdb)" >&2
+    exit 1
+    ;;
+esac
+
+# Ensure the path has a single leading slash and no trailing slash
+if [ "$BASE_PATH" != "/" ]; then
+  BASE_PATH="/${BASE_PATH#/}"
+  BASE_PATH="${BASE_PATH%/}"
+fi
+
+# Derive helper variants used by the templated replacements below
+if [ "$BASE_PATH" = "/" ]; then
+  BASE_PATH_WITH_SLASH="/"
+  BASE_PATH_NO_LEAD=""
+  BASE_PATH_NO_LEAD_WITH_SLASH=""
+else
+  BASE_PATH_WITH_SLASH="$BASE_PATH/"
+  BASE_PATH_NO_LEAD="${BASE_PATH#/}"
+  BASE_PATH_NO_LEAD_WITH_SLASH="${BASE_PATH_NO_LEAD}/"
+fi
+
+# Replace the placeholder base path in built assets, if present
+if grep -R "__BASE_PATH__" "$CONTENT_DIR" >/dev/null 2>&1; then
+  find "$CONTENT_DIR" -type f \( -name '*.js' -o -name '*.css' -o -name '*.html' -o -name '*.json' -o -name '*.txt' \) -print0 |
+    while IFS= read -r -d '' file; do
+      sed -i \
+        -e "s|/__BASE_PATH__/|${BASE_PATH_WITH_SLASH}|g" \
+        -e "s|/__BASE_PATH__|${BASE_PATH}|g" \
+        -e "s|__BASE_PATH__/|${BASE_PATH_NO_LEAD_WITH_SLASH}|g" \
+        -e "s|__BASE_PATH__|${BASE_PATH_NO_LEAD}|g" \
+        "$file"
+    done
+fi
+
+# Generate Nginx configuration matching the selected base path
+if [ "$BASE_PATH" = "/" ]; then
+  cat >/etc/nginx/conf.d/default.conf <<'EOF'
+server {
+  listen 80;
+  server_name _;
+  root /usr/share/nginx/html;
+
+  location / {
+    try_files $uri $uri/ /index.html;
+  }
+}
+EOF
+else
+  cat >/etc/nginx/conf.d/default.conf <<EOF
+server {
+  listen 80;
+  server_name _;
+  root /usr/share/nginx/html;
+
+  location = $BASE_PATH {
+    return 301 $BASE_PATH/;
+  }
+
+  location $BASE_PATH/ {
+    rewrite ^$BASE_PATH/(.*)$ /\$1 break;
+    try_files \$uri \$uri/ /index.html;
+  }
+}
+EOF
+fi
+
+exec "$@"

src/App.jsx

@@ -8,9 +8,11 @@ import SettingsContextProvider from "./context/SettingsContext";
 import NotFound from "./pages/NotFound";
 
 export default function App() {
+  const basename = import.meta.env.BASE_URL.replace(/\/$/, "");
+
   return (
     <SettingsContextProvider>
-      <BrowserRouter>
+      <BrowserRouter basename={basename || undefined}>
         <RestoreScroll />
         <Routes>
           <Route path="/" element={<LandingPage />} />

vite.config.js

@@ -1,7 +1,19 @@
-import { defineConfig } from 'vite'
-import react from '@vitejs/plugin-react'
+/* eslint-env node */
+import { defineConfig, loadEnv } from "vite";
+import react from "@vitejs/plugin-react";
 
-// https://vitejs.dev/config/
-export default defineConfig({
-  plugins: [react()],
-})
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), "");
+  let base = env.VITE_BASE_PATH || "/";
+  if (!base.startsWith("/") && !/^https?:\/\//.test(base)) {
+    base = `/${base}`;
+  }
+  if (!base.endsWith("/")) {
+    base += "/";
+  }
+
+  return {
+    base,
+    plugins: [react()],
+  };
+});