Plugging in an existing third-party logger provider

NLog was one of the very first loggers that was available as a .NET Standard library and usable in ASP.NET Core. NLog also already provides a logger provider to easily plug into ASP.NET Core.

You will find NLog via NuGet (https://www.nuget.org/packages/NLog.Web.AspNetCore) and on GitHub (https://github.com/NLog/NLog.Web). Even if NLog is not yet explicitly available for ASP.NET Core 5.0, it will nevertheless work with this version:

1. We need to add an NLog.Config file that defines two different sinks to log all messages in a single log file, and custom messages only in another file. Since this file is too long to print, you can view it or download it directly from GitHub: https://github.com/PacktPublishing/Customizing-ASP.NET-Core-5.0/blob/main/Chapter01/LoggingSample5.0/NLog.Config.
2. We then need to add the NLog ASP.NET Core package from NuGet:

   dotnet add package NLog.Web.AspNetCore

   Important note

   Be sure that you are in...