configurationdotnetcoreconsoleappthree.cs

class Program
{
    static void Main(string[] args)
    {
        var cfg = InitSettings<AppConfig>();

        var loggingUrl = cfg.Logging.Url;
        var loggingUsername = cfg.Logging.Username;
        var corsAllowedMethods = cfg.CorsAllowedMethods;
        Console.WriteLine($"{loggingUrl} {loggingUsername} {corsAllowedMethods}");
        Console.ReadKey();
    }

    private static T InitSettings<T>() where T : new()
    {
        var config = InitConfig();
        return config.Get<T>();
    }

    private static IConfigurationRoot InitConfig()
    {
        // load setup file name and path from appsettings.json 
        var builder = new ConfigurationBuilder()
            .AddJsonFile($"appsettings.json", true, true)
            .AddEnvironmentVariables();

        return builder.Build();
    }
}