DRAWIO_BASE_URL parameter not working with bind-mounted PreConfig.js & reverse proxy #46

location /diagram { # begin diagram block
        auth_request /auth-4;
        proxy_pass  https://diagram-url:8443/;
        add_header X-Frame-Options "SAMEORIGIN";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
} 

version: '3.5'
services:
  drawio:
    image: fjudith/draw.io
    container_name: drawio
    restart: unless-stopped
    ports:
      - 8080:8080
      - 8443:8443
    environment:
      PUBLIC_DNS: example.org
    volumes:
      - ./config/PreConfig.js:/usr/local/tomcat/webapps/draw/js/PreConfig.js

/**
 * Copyright (c) 2006-2019, JGraph Ltd
 * Copyright (c) 2006-2019, draw.io AG
 */
// Overrides of global vars need to be pre-loaded
window.EXPORT_URL = '/export'; //This points to ExportProxyServlet which uses the local export server at port 8000.
//This proxy configuration allows https requests to the export server via Tomcat.
window.PLANT_URL = 'REPLACE_WITH_YOUR_PLANTUML_SERVER';
// window.DRAWIO_BASE_URL = 'https://mcp.lunacite.com/diagram';
// window.DRAWIO_VIEWER_URL = 'https://mcp.lunacite.com/diagram/js/viewer.min.js';
window.DRAW_MATH_URL = 'math';
window.DRAWIO_CONFIG = null; //Replace with your custom draw.io configurations. For more details, https://desk.draw.io/support/solutions/articles/16000058316