internal static void ConfigureWebDefaults(IWebHostBuilder builder) { builder.ConfigureAppConfiguration((ctx, cb) => { if (ctx.HostingEnvironment.IsDevelopment()) { StaticWebAssetsLoader.UseStaticWebAssets(ctx.HostingEnvironment, ctx.Configuration); } }); builder.UseKestrel((builderContext, options) => { options.Configure(builderContext.Configuration.GetSection("Kestrel"), reloadOnChange: true); }) .ConfigureServices((hostingContext, services) => { // Fallback services.PostConfigure <HostFilteringOptions>(options => { if (options.AllowedHosts == null || options.AllowedHosts.Count == 0) { // "AllowedHosts": "localhost;127.0.0.1;[::1]" var hosts = hostingContext.Configuration["AllowedHosts"]?.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries); // Fall back to "*" to disable. options.AllowedHosts = (hosts?.Length > 0 ? hosts : new[] { "*" }); } }); // Change notification services.AddSingleton <IOptionsChangeTokenSource <HostFilteringOptions> >( new ConfigurationChangeTokenSource <HostFilteringOptions>(hostingContext.Configuration)); services.AddTransient <IStartupFilter, HostFilteringStartupFilter>(); if (string.Equals("true", hostingContext.Configuration["ForwardedHeaders_Enabled"], StringComparison.OrdinalIgnoreCase)) { services.Configure <ForwardedHeadersOptions>(options => { options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto; // Only loopback proxies are allowed by default. Clear that restriction because forwarders are // being enabled by explicit configuration. options.KnownNetworks.Clear(); options.KnownProxies.Clear(); }); services.AddTransient <IStartupFilter, ForwardedHeadersStartupFilter>(); } services.AddRouting(); }) .UseIIS() .UseIISIntegration(); }