How do I control logging via a configuration file in a .NET *Framework* app using Microsoft.Extensions.Logging?

[IanKemp]

https://docs.microsoft.com/en-us/dotnet/core/extensions/logging?tabs=command-line#configure-logging explains how to configure logging for .NET Core applications using appsettings.json, but obviously that file isn't relevant for .NET Framework apps that use app.config. I'm trying to see debug logs that my application is emitting, but since the default log level is info, these entries never appear. I've tried adding various elements to my app.config to mimic what's in appsettings.json but so far haven't found something that works; the only thing that does is calling ILoggingBuilder.SetMinimumLevel(LogLevel.Debug) in the service container construction, but of course that is not runtime-configurable.

Is this even possible in ye olde Framework land? If so and you've done it yourself (without using a third-party logging framework and/or reinventing the wheel), please share the details!