NethVoice Proxy: Public IP address disappears after saving configuration

[andre8244]

Steps to reproduce

• Go to the Settings page of NethVoice Proxy
• Enter Network interface and Public IP address
• Click Save

Expected behavior

After the configuration task completes, the form reloads and the input fields display the values the user just entered

Actual behavior

The field Public IP address appears empty

Components

ns8-nethvoice-proxy

Screencast_20250924_101915.webm

[Amygos]

The apparent incorrect behavior is present only if the public IP address is the same as the selected network interface.
If the two IP addresses are the same, this is semantically equivalent to leaving the public IP field empty, and so in this case the UI doesn't pass the value to the backend.

See the relevant UI code: https://github.com/nethesis/ns8-nethvoice-proxy/blob/a4788f4b055b6bb650c379b7f346db93b4ea6758/ui/src/views/Settings.vue#L441

A configuration where the two values are the same, if passed to the backend, is an incorrect one.

The public IP address field must be populated only in a scenario where the NAT is present.

[andre8244]

Even if the current behavior is technically correct from a backend perspective, it is unexpected and potentially misleading from a UX standpoint.

I suggest the following improvements:

• Since this is an invalid configuration, if the user enters the same IP for both “Public IP address” and “Network interfaces,” a validation error should be raised. If modifying the configure-module action isn’t desirable, we can still raise the validation error on the frontend (though that’s less ideal).
• If the “Public IP address” field is optional, then “(Optional)” should be displayed next to the “Network interfaces” label.
• Off-topic: since only one network interface can be selected, the field label should be “Network interface” (singular).

[Amygos]

Testing release nethesis/ns8-nethvoice-proxy 1.5.1-testing.3