Kestrel port binding default to 80 or 443 / No error/warn/info/debug when "{abc}" provided

[tebeco]

Hello,

After few long minutes (hours?) of debugging we found out that invalid port configuration will not say anything and silent.
Why did it takes so long ?
Because we were looking for the https binding that was https://*:8443 on our POD, and it seems that another appsettings...json file still had an http://*:{place.holder} that was not replaced
So it seems that it defaulted to port 80 without saying anything at all.

The behavior was AccessDeniedException on a Socket (because Pods should not run as root so any binding bellow 1024 is forbidden)

The log level has been changed to debug for this capture :

so I wonder about 3 things now :

• should the SocketException / AccessDenied be explicit on the full binding url that was denied ? => http://[::]:80 or http://*:80`
• should there be at least a WARNING on the fact that a string with letter and placerhoder is probably not a valid URI / Port ?
• is there any form of URI that would makes this valid: http://*:{foo.bar.kix} with the port 80 ?

[poke]

This appears to be a problem with BindingAdress.Parse which gets called early in the AddressBinder. Since the binder is not able to produce a better result from the input, it will eventually fall back to just binding on the port that the BindingAdress contains:

aspnetcore/src/Servers/Kestrel/Core/src/Internal/AddressBinder.cs

Lines 135 to 139 in 4aa5e03

	else
	{
	// when address is 'http://hostname:port', 'http://*:port', or 'http://+:port'
	options = new AnyIPListenOptions(parsedAddress.Port);
	}

Unfortunately, BindingAddress.Parse does not appear to parse the input very well:

Calling BindingAddress.Parse("https://*:{abc}") will recognize *:{abc} as the host and assume the default HTTPS port 443.

[tebeco]

well then, created an issue on that one :
#24384