[Feature Request] Support for Custom Base URL Prefix in Calibre-Web (Flask Backend)

[T1t4m1un]

Description

I am using Calibre-Web with Traefik as a reverse proxy, routing the service under a custom path prefix (e.g., /calibre-web). While the Traefik configuration correctly proxies requests to the service, Calibre-Web returns a 404 error due to the application expecting root-level access. So I require the ability to configure a custom base URL (/calibre-web) to support routing under a prefixed path without affecting the root path or other services.

Feature Request

Enable Calibre-Web to operate under a configurable base URL (e.g., /calibre-web)

• Allowing the application to set a base URL or APPLICATION_ROOT variable that adapts all routes and static assets to a prefixed
• Updating internal routes and static file paths to honor the base URL prefix, making them accessible through the proxied path in Traefik or etc.

Why This Feature is

• Proxy Compatibility: It ensures compatibility with reverse proxies that map services to specific paths, especially in multi-service
• Scalability and Organization: Supports multi-path deployment, crucial for users running multiple services (e.g., /sun-panel, /calibre-web) within a single
• Ease of Access: Users can maintain consistent URLs across services without altering Traefik or other proxy settings.

Potential Impact on Other Users

This feature would be optional and configurable, allowing users to retain root access or specify a path prefix as needed.

[OzzieIsaacs]

It‘s possible to configure a proxy to work flawlessly with calibre-web, I know traefik config is a bit tricky (I did it once and will not do it again, there is a example in the wiki: https://github.com/janeczku/calibre-web/wiki/Setup-Reverse-Proxy#traefik-200)