How to pass dependencies to a custom .NET Core ILoggerProvider

Now I am not sure if an extension already exists to do this but I see potential here.

First this is how AddProvider is defined in the source code repo.

public static ILoggingBuilder AddProvider(this ILoggingBuilder builder, ILoggerProvider provider) {
    builder.Services.AddSingleton(provider);
    return builder;
}

You could build up on that by making your own generic version

public static class MyLoggingBuilderExtensions {
    public static ILoggingBuilder AddProvider<T>(this ILoggingBuilder builder)
        where T: class, ILoggerProvider{
        builder.Services.AddSingleton<ILoggerProvider, T>();
        return builder;
    }
}

which should allow the DI container to build up the object graph when resolved

services.AddLogging(builder =>
{
    builder.AddProvider<CustomLoggerProvider>();
});

And there is room to extend this functionality, like adding your own overload that exposes the IServiceProvider and passing that on to the AddSingleton within the extension.

public static ILoggingBuilder AddProvider<T>(this ILoggingBuilder builder, Func<IServiceProvider, T> factory)
    where T: class, ILoggerProvider {
    builder.Services.AddSingleton<ILoggerProvider, T>(factory);
    return builder;
}

And used

services.AddLogging(builder => {
    builder.AddProvider<CustomLoggerProvider>(p => new CustomLoggerProvider("Constant value", p.GetService<IMyService>()));
});