asp.net Core 2 Web API appsetting.json values aren't being read when deployed as windows service

I am running an asp.net core 2 web api as a windows service. When I debug through IIS I am able to read my configuration values no problem.

However, once I run it as a service I am not getting any values back.

appsettings.json

{
  "Database": {
    "DatabaseName": "testdb",
    "DatabaseServer": "localhost",
    "DatabaseUserName": "admin",
    "DatabasePassword": "admin"
  }
}

 public string GetConnectionString()
    {
        var databaseName = Configuration["Database:DatabaseName"];
        var databaseServer = Configuration["Database:DatabaseServer"];
        var username = Configuration["Database:DatabaseUserName"];
        var password = Configuration["Database:DatabasePassword"];


        return $"Data Source={databaseServer};Initial Catalog={databaseName};Persist Security Info=True;User ID={username};Password={password};MultipleActiveResultSets=True";
    }

Not sure why I can't read those values once I publish the application. In the published appsettings.json file the values are there.

Here is my startup.cs. I was under the impression that I didn't have to reference teh appSettings.json file in the new asp.net core 2. Thanks for the help.

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
        AutoMapper.Mapper.Initialize(cfg =>
        {
            cfg.CreateMap<InventoryTransaction, Models.InventoryTransactionModel>();
            cfg.CreateMap<ReasonCode, Models.ReasonCodeModel>();
            cfg.CreateMap<InventoryTransaction, Models.InventoryTransactionForCreationModel>();
            cfg.CreateMap<InventoryTransactionForCreationModel, InventoryTransaction>();
        });
        services.AddScoped<IInventoryTransactionRepository, InventoryTransactionRepository>();
        services.AddSingleton<IConfiguration>(Configuration);
        services.AddDbContext<VPSInventoryContext>(options => options.UseSqlServer(GetConnectionString()));

    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole();
        loggerFactory.AddDebug();
        loggerFactory.AddNLog();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseMvc();

    }

    public string GetConnectionString()
    {
        var databaseName = Configuration["Database:DatabaseName"];
        var databaseServer = Configuration["Database:DatabaseServer"];
        var username = Configuration["Database:DatabaseUserName"];
        var password = Configuration["Database:DatabasePassword"];


        return $"Data Source={databaseServer};Initial Catalog={databaseName};Persist Security Info=True;User ID={username};Password={password};MultipleActiveResultSets=True";
    }
}

Here is my Program.cs where I run it as a windows service.

public class Program
{
    public static void Main(string[] args)
    {
        if (Debugger.IsAttached || args.Contains("--debug"))
        {
            BuildWebHost(args).Run();
        }
        else
        {
            BuildWebHost(args).RunAsService();
        }
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}