Startup.cs

namespace WebhookClient;

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.AddSession(opt =>
            {
                opt.Cookie.Name = ".eShopWebhooks.Session";
            })
            .AddConfiguration(Configuration)
            .AddHttpClientServices(Configuration)
            .AddCustomAuthentication(Configuration)
            .AddTransient<IWebhooksClient, WebhooksClient>()
            .AddSingleton<IHooksRepository, InMemoryHooksRepository>()
            .AddMvc();

        services.AddControllers();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {

        var pathBase = Configuration["PATH_BASE"];
        if (!string.IsNullOrEmpty(pathBase))
        {
            app.UsePathBase(pathBase);
        }

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
        }
        app.Map("/check", capp =>
        {
            capp.Run(async (context) =>
            {
                if ("OPTIONS".Equals(context.Request.Method, StringComparison.InvariantCultureIgnoreCase))
                {
                    var validateToken = bool.TrueString.Equals(Configuration["ValidateToken"], StringComparison.InvariantCultureIgnoreCase);
                    var header = context.Request.Headers[HeaderNames.WebHookCheckHeader];
                    var value = header.FirstOrDefault();
                    var tokenToValidate = Configuration["Token"];
                    if (!validateToken || value == tokenToValidate)
                    {
                        if (!string.IsNullOrWhiteSpace(tokenToValidate))
                        {
                            context.Response.Headers.Add(HeaderNames.WebHookCheckHeader, tokenToValidate);
                        }
                        context.Response.StatusCode = (int)HttpStatusCode.OK;
                    }
                    else
                    {
                        await context.Response.WriteAsync("Invalid token");
                        context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
                    }
                }
                else
                {
                    context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
                }
            });
        });

        // Fix samesite issue when running eShop from docker-compose locally as by default http protocol is being used
        // Refer to https://github.com/dotnet-architecture/eShopOnContainers/issues/1391
        app.UseCookiePolicy(new CookiePolicyOptions { MinimumSameSitePolicy = SameSiteMode.Lax });

        app.UseStaticFiles();
        app.UseSession();
        app.UseRouting();
        app.UseAuthentication();
        app.UseAuthorization();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapDefaultControllerRoute();
            endpoints.MapRazorPages();
        });
    }
}

static class ServiceExtensions
{
    public static IServiceCollection AddConfiguration(this IServiceCollection services, IConfiguration configuration)
    {
        services.AddOptions();
        services.Configure<Settings>(configuration);
        return services;
    }
    public static IServiceCollection AddCustomAuthentication(this IServiceCollection services, IConfiguration configuration)
    {
        var identityUrl = configuration.GetValue<string>("IdentityUrl");
        var callBackUrl = configuration.GetValue<string>("CallBackUrl");

        // Add Authentication services          

        services.AddAuthentication(options =>
        {
            options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
            options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
        })
        .AddCookie(setup => setup.ExpireTimeSpan = TimeSpan.FromHours(2))
        .AddOpenIdConnect(options =>
        {
            options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
            options.Authority = identityUrl.ToString();
            options.SignedOutRedirectUri = callBackUrl.ToString();
            options.ClientId = "webhooksclient";
            options.ClientSecret = "secret";
            options.ResponseType = "code";
            options.SaveTokens = true;
            options.GetClaimsFromUserInfoEndpoint = true;
            options.RequireHttpsMetadata = false;
            options.Scope.Add("openid");
            options.Scope.Add("webhooks");
        });

        return services;
    }

    public static IServiceCollection AddHttpClientServices(this IServiceCollection services, IConfiguration configuration)
    {
        services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
        services.AddTransient<HttpClientAuthorizationDelegatingHandler>();
        services.AddHttpClient("extendedhandlerlifetime").SetHandlerLifetime(Timeout.InfiniteTimeSpan);

        //add http client services
        services.AddHttpClient("GrantClient")
                .SetHandlerLifetime(TimeSpan.FromMinutes(5))
                .AddHttpMessageHandler<HttpClientAuthorizationDelegatingHandler>();

        return services;
    }
}