<PackageReference Include="Microsoft.AspNetCore" Version="2.0.2" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.3" />
<PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="2.0.3" PrivateAssets="All" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.0.2" />
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="2.0.2" />

<PackageReference Include="Microsoft.SqlServer.Types" Version="11.0.2" />
<PackageReference Include="FluentValidation.AspNetCore" Version="7.5.2" />

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

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

public IConfiguration Configuration { get; }

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

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        // Load Configuration from appsettings.json
        services.Configure<IdentityServerSettings>(Configuration.GetSection("IdentityServerSettings"));
        services.AddOptions();

        var identityServerOptions = serviceProvider.GetService<IOptions<IdentityServerSettings>>().Value;
        services.AddMvc(o =>
        {
            if (identityServerOptions.EnableSSL)
                o.Filters.Add(new RequireHttpsAttribute());
        });

        services.AddAuthentication("Bearer").AddIdentityServerAuthentication(opt =>
            {
                opt.Authority = identityServerOptions.Authority;
                opt.RequireHttpsMetadata = identityServerOptions.EnableSSL;
                opt.ApiName = identityServerOptions.ApiName;
            });
    }


    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        #region Identity Server Config
        // Setup Identity Server Options for this API -
        app.UseAuthentication();

        #endregion

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        // tried this
        app.UseMvc();

        // and this
        //app.UseMvcWithDefaultRoute();

        // and this
        //app.UseMvc(routes =>
        //{
        //    routes.MapRoute(name: "default", template: "{controller=Home}/{action=Index}/{id?}");
        //});
    }

app.UseMvc(routes =>
            {
                routes.MapRoute(name: "default", template: "{controller=Home}/{action=Index}/{id?}");
            });