PluralKit/PluralKit.Core/Modules/ConfigModule.cs

using Autofac;

using Microsoft.Extensions.Configuration;

namespace PluralKit.Core
{
    public class ConfigModule<T>: Module where T : new()
    {
        private readonly string _submodule;

        public ConfigModule(string submodule = null)
        {
            _submodule = submodule;
        }

        protected override void Load(ContainerBuilder builder)
        {
            // We're assuming IConfiguration is already available somehow - it comes from various places (auto-injected in ASP, etc)

            // Register the CoreConfig and where to find it
            builder.Register(c => c.Resolve<IConfiguration>().GetSection("PluralKit").Get<CoreConfig>() ?? new CoreConfig()).SingleInstance();

            // Register the submodule config (BotConfig, etc) if specified
            if (_submodule != null)
                builder.Register(c => c.Resolve<IConfiguration>().GetSection("PluralKit").GetSection(_submodule).Get<T>() ?? new T()).SingleInstance();
        }
    }
}