SystemCommandLineProgram.cs

internal static class Program
{
    /// <summary>
    /// The entry point for the program.
    /// </summary>
    /// <param name="args">The arguments.</param>
    /// <returns>When complete, an integer representing success (0) or failure (non-0).</returns>
    public static async Task<int> Main(string[] args)
    {
        ServiceProvider serviceProvider = BuildServiceProvider();
        Parser parser = BuildParser(serviceProvider);

        return await parser.InvokeAsync(args).ConfigureAwait(false);
    }

    private static Parser BuildParser(ServiceProvider serviceProvider)
    {
        var commandLineBuilder = new CommandLineBuilder();

        foreach (Command command in serviceProvider.GetServices<Command>())
        {
            commandLineBuilder.AddCommand(command);
        }

        return commandLineBuilder.UseDefaults().Build();
    }

    private static ServiceProvider BuildServiceProvider()
    {
        var services = new ServiceCollection();
        IConfigurationRoot config = new ConfigurationBuilder()
            .AddJsonFile("appsettings.json")
            .Build();

        services.AddSingleton<IConfiguration>(config);
        services.AddCliCommands();

        return services.BuildServiceProvider();
    }
}