NLog - Capture host's ip address

I am trying to capture the host / server's ipaddress within a .NET Core 2.0 application. The ${machinename} variable captures the server's name but how do you capture the server's IP address? The name is meaningless to my team but IP address is critical.

Solution

Lets say you have a static IP-address, then you can do this:

var localIpAddress = LookupIpAddress(); // See https://stackoverflow.com/a/50386894/193178
NLog.GlobalDiagnosticsContext.Set("LocalIpAddress", localIpAddress);

Then you can use it target layout like this:

layout="${longdate}|${level}|${logger}|${message}|${gdc=LocalIpAddress}"

If your IP-address sometimes are changing, then you can setup a background-thread/timer to refresh the NLog-GDC-value.