eShopOnContainers/src/Services/Coupon/Coupon.API/Startup.cs

using Autofac;
using Coupon.API.Controllers;
using Coupon.API.Infrastructure;
using Coupon.API.Infrastructure.Filters;
using Coupon.API.Middlewares;
using Coupon.API.Services;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBus;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ;
using Microsoft.eShopOnContainers.BuildingBlocks.EventBusServiceBus;
using Microsoft.Extensions.Options;
using Microsoft.OpenApi.Models;
using RabbitMQ.Client;
using System.IdentityModel.Tokens.Jwt;
using Autofac.Extensions.DependencyInjection;
using Microsoft.AspNetCore.Diagnostics.HealthChecks;
using HealthChecks.UI.Client;
using Coupon.API.IntegrationEvents.EventHandling;
using Coupon.API.IntegrationEvents.Events;

namespace Coupon.API
{
    public class Startup
    {
        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 virtual IServiceProvider ConfigureServices(IServiceCollection services)
        {
            //services.AddGrpc(options =>
            //{
            //    options.EnableDetailedErrors = true;
            //});

            RegisterAppInsights(services);

            services.AddControllers(options =>
            {
                options.Filters.Add(typeof(HttpGlobalExceptionFilter));
                //options.Filters.Add(typeof(ValidateModelStateFilter));

            }) // Added for functional tests
                .AddApplicationPart(typeof(CouponController).Assembly)
                .AddJsonOptions(options => options.JsonSerializerOptions.WriteIndented = true);

            services.AddSwaggerGen(options =>
            {
                options.SwaggerDoc("v1", new OpenApiInfo
                {
                    Title = "eShopOnContainers - Coupon HTTP API",
                    Version = "v1",
                    Description = "The Coupon Service HTTP API"
                });

                options.AddSecurityDefinition("oauth2", new OpenApiSecurityScheme
                {
                    Type = SecuritySchemeType.OAuth2,
                    Flows = new OpenApiOAuthFlows()
                    {
                        Implicit = new OpenApiOAuthFlow()
                        {
                            AuthorizationUrl = new Uri($"{Configuration.GetValue<string>("IdentityUrlExternal")}/connect/authorize"),
                            TokenUrl = new Uri($"{Configuration.GetValue<string>("IdentityUrlExternal")}/connect/token"),
                            Scopes = new Dictionary<string, string>()
                        {
                            { "basket", "Basket API" }
                        }
                        }
                    }
                });

                options.OperationFilter<AuthorizeCheckOperationFilter>();
            });

            ConfigureAuthService(services);

            services.AddCustomHealthCheck(Configuration);

            services.Configure<CouponSettings>(Configuration);

            //By connecting here we are making sure that our service
            //cannot start until redis is ready. This might slow down startup,
            //but given that there is a delay on resolving the ip address
            //and then creating the connection it seems reasonable to move
            //that cost to startup instead of having the first request pay the
            //penalty.
            //services.AddSingleton<ConnectionMultiplexer>(sp =>
            //{
            //    var settings = sp.GetRequiredService<IOptions<CouponSettings>>().Value;
            //    var configuration = ConfigurationOptions.Parse(settings.ConnectionString, true);

            //    return ConnectionMultiplexer.Connect(configuration);
            //});


            if (Configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IServiceBusPersisterConnection>(sp =>
                {
                    var serviceBusConnectionString = Configuration["EventBusConnection"];

                    return new DefaultServiceBusPersisterConnection(serviceBusConnectionString);
                });
            }
            else
            {
                services.AddSingleton<IRabbitMQPersistentConnection>(sp =>
                {
                    var logger = sp.GetRequiredService<ILogger<DefaultRabbitMQPersistentConnection>>();

                    var factory = new ConnectionFactory()
                    {
                        HostName = Configuration["EventBusConnection"],
                        DispatchConsumersAsync = true
                    };

                    if (!string.IsNullOrEmpty(Configuration["EventBusUserName"]))
                    {
                        factory.UserName = Configuration["EventBusUserName"];
                    }

                    if (!string.IsNullOrEmpty(Configuration["EventBusPassword"]))
                    {
                        factory.Password = Configuration["EventBusPassword"];
                    }

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(Configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(Configuration["EventBusRetryCount"]);
                    }

                    return new DefaultRabbitMQPersistentConnection(factory, logger, retryCount);
                });
            }

            RegisterEventBus(services);


            services.AddCors(options =>
            {
                options.AddPolicy("CorsPolicy",
                    builder => builder
                    .SetIsOriginAllowed((host) => true)
                    .AllowAnyMethod()
                    .AllowAnyHeader()
                    .AllowCredentials());
            });
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddTransient<ICouponRepository, CouponRepository>();
            services.AddTransient<IIdentityService, IdentityService>();

            services.AddOptions();

            var container = new ContainerBuilder();
            container.Populate(services);

            return new AutofacServiceProvider(container.Build());
        }

        private void RegisterAppInsights(IServiceCollection services)
        {
            services.AddApplicationInsightsTelemetry(Configuration);
            services.AddApplicationInsightsKubernetesEnricher();
        }

        private void ConfigureAuthService(IServiceCollection services)
        {
            // prevent from mapping "sub" claim to nameidentifier.
            JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Remove("sub");

            var identityUrl = Configuration.GetValue<string>("IdentityUrl");

            services.AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

            }).AddJwtBearer(options =>
            {
                options.Authority = identityUrl;
                options.RequireHttpsMetadata = false;
                options.Audience = "basket";
            });
        }

        private void RegisterEventBus(IServiceCollection services)
        {
            if (Configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IEventBus, EventBusServiceBus>(sp =>
                {
                    var serviceBusPersisterConnection = sp.GetRequiredService<IServiceBusPersisterConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusServiceBus>>();
                    var eventBusSubscriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();
                    string subscriptionName = Configuration["SubscriptionClientName"];

                    return new EventBusServiceBus(serviceBusPersisterConnection, logger,
                        eventBusSubscriptionsManager, iLifetimeScope, subscriptionName);
                });
            }
            else
            {
                services.AddSingleton<IEventBus, EventBusRabbitMQ>(sp =>
                {
                    var subscriptionClientName = Configuration["SubscriptionClientName"];
                    var rabbitMQPersistentConnection = sp.GetRequiredService<IRabbitMQPersistentConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusRabbitMQ>>();
                    var eventBusSubscriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(Configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(Configuration["EventBusRetryCount"]);
                    }

                    return new EventBusRabbitMQ(rabbitMQPersistentConnection, logger, iLifetimeScope, eventBusSubscriptionsManager, subscriptionClientName, retryCount);
                });
            }

            services.AddSingleton<IEventBusSubscriptionsManager, InMemoryEventBusSubscriptionsManager>();

            //services.AddTransient<ProductPriceChangedIntegrationEventHandler>();
            services.AddTransient<OrderStatusChangedToAwaitingCouponValidationIntegrationEventHandler>();
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
        {
            //loggerFactory.AddAzureWebAppDiagnostics();
            //loggerFactory.AddApplicationInsights(app.ApplicationServices, LogLevel.Trace);

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

            app.UseSwagger()
                .UseSwaggerUI(setup =>
                {
                    setup.SwaggerEndpoint($"{(!string.IsNullOrEmpty(pathBase) ? pathBase : string.Empty)}/swagger/v1/swagger.json", "1Basket.API V1");
                    setup.OAuthClientId("basketswaggerui");
                    setup.OAuthAppName("Basket Swagger UI");
                });

            app.UseRouting();
            app.UseCors("CorsPolicy");
            ConfigureAuth(app);

            app.UseStaticFiles();

            app.UseEndpoints(endpoints =>
            {
                //endpoints.MapGrpcService<BasketService>();
                endpoints.MapDefaultControllerRoute();
                endpoints.MapControllers();
                //endpoints.MapGet("/_proto/", async ctx =>
                //{
                //    ctx.Response.ContentType = "text/plain";
                //    using var fs = new FileStream(Path.Combine(env.ContentRootPath, "Proto", "basket.proto"), FileMode.Open, FileAccess.Read);
                //    using var sr = new StreamReader(fs);
                //    while (!sr.EndOfStream)
                //    {
                //        var line = await sr.ReadLineAsync();
                //        if (line != "/* >>" || line != "<< */")
                //        {
                //            await ctx.Response.WriteAsync(line);
                //        }
                //    }
                //});
                endpoints.MapHealthChecks("/hc", new HealthCheckOptions()
                {
                    Predicate = _ => true,
                    ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
                });
                endpoints.MapHealthChecks("/liveness", new HealthCheckOptions
                {
                    Predicate = r => r.Name.Contains("self")
                });
            });

            ConfigureEventBus(app);
        }

        protected virtual void ConfigureAuth(IApplicationBuilder app)
        {
            app.UseAuthentication();
            app.UseAuthorization();
        }

        private void ConfigureEventBus(IApplicationBuilder app)
        {
            var eventBus = app.ApplicationServices.GetRequiredService<IEventBus>();

            //eventBus.Subscribe<ProductPriceChangedIntegrationEvent, ProductPriceChangedIntegrationEventHandler>();
            eventBus.Subscribe<OrderStatusChangedToAwaitingCouponValidationIntegrationEvent, OrderStatusChangedToAwaitingCouponValidationIntegrationEventHandler>();
        }
    }
}