Added BASE_URL support to the Dockerfile

Dockerfile

@@ -1,3 +1,7 @@
+# global variable declaration:
+#  -Build to serve under Subdirectory BASE_URL if provided, eg: "ARG BASE_URL=/pdf/", otherwise leave blank: "ARG BASE_URL="
+ARG BASE_URL=
+
 # Build stage
 FROM node:20-alpine AS builder
 WORKDIR /app
@@ -7,16 +11,28 @@ COPY . .
 
 # Build without type checking (vite build only)
 # Pass SIMPLE_MODE environment variable if provided
-ARG SIMPLE_MODE=false
+ARG SIMPLE_MODE=true
 ENV SIMPLE_MODE=$SIMPLE_MODE
-RUN npm run build -- --mode production
+
+# global arg to local arg
+ARG BASE_URL
+ENV BASE_URL=$BASE_URL
+
+RUN if [ -z "$BASE_URL" ]; then \
+      npm run build -- --mode production; \
+    else \
+      npm run build -- --base=${BASE_URL} --mode production; \
+    fi
 
 # Production stage
 FROM nginxinc/nginx-unprivileged:stable-alpine-slim
 
 LABEL org.opencontainers.image.source="https://github.com/alam00000/bentopdf"
 
-COPY --chown=nginx:nginx --from=builder /app/dist /usr/share/nginx/html
+# global arg to local arg
+ARG BASE_URL
+
+COPY --chown=nginx:nginx --from=builder /app/dist /usr/share/nginx/html${BASE_URL%/}
 COPY --chown=nginx:nginx nginx.conf /etc/nginx/nginx.conf
 RUN mkdir -p /etc/nginx/tmp && chown -R nginx:nginx /etc/nginx/tmp
 
@@ -24,6 +40,7 @@ EXPOSE 8080
 CMD ["nginx", "-g", "daemon off;"]
 
 
+
 # Old Dockerfile for Root User
 # # Build stage
 # FROM node:20-alpine AS builder