Log Display for Multiple Network Interfaces when Binding to 0.0.0.0

[chn-lee-yumi]

Hello Werkzeug maintainers and community,

I've been working with Werkzeug's development server and noticed a potential improvement regarding its log output when binding to multiple network interfaces.

When setting host='0.0.0.0', the server listens on all available network interfaces, which is the expected behaviour. However, the log output only displays a limited set of addresses:

 * Running on all addresses (0.0.0.0)
 * Running on http://127.0.0.1:8085
 * Running on http://192.168.2.2:8085

Looking into the source code here, it seems the log message appends only the localhost and display_hostname addresses.

This can be misleading for users with multiple active network interfaces (e.g., Ethernet and Wi-Fi), as they might expect all interface addresses to be printed in the logs. Someone reported this problem to me here (written in Chinese).

Would it be helpful to display all available interface addresses when binding to 0.0.0.0?

If this is something the community would find valuable, I'd be happy to contribute a PR to enhance the log output.

[davidism]

No. This is intended only to help with the common scenario of hosting on 0.0.0.0 within a Docker container, where the standard localhost message would not result in a valid connection. Keep in mind, the development server is never intended for production use, so giving more helpful information when binding to external interfaces is not helpful towards that purpose.