Startup.cs

 
using System;
using Autofac;
using Autofac.Extensions.DependencyInjection;
using Identity.Api.Messaging.Consumers;
using Identity.Api.Models;
using Identity.Api.Services;
using MassTransit;
using MassTransit.Util;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using StackExchange.Redis;

namespace Identity.Api
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IContainer ApplicationContainer { get; private set; }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();

            //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(sp =>
            {
                var configuration = new ConfigurationOptions {ResolveDns = true};
                configuration.EndPoints.Add(Configuration["RedisHost"]);
                return ConnectionMultiplexer.Connect(configuration);
            });

            services.AddTransient<IIdentityRepository, IdentityRepository>();
            var builder = new ContainerBuilder();

            // register a specific consumer
            builder.RegisterType<ApplicantAppliedEventConsumer>();

            builder.Register(context =>
                {
                    var busControl = Bus.Factory.CreateUsingRabbitMq(cfg =>
                    {
                        var host = cfg.Host(new Uri("rabbitmq://rabbitmq/"), h =>
                        {
                            h.Username("guest");
                            h.Password("guest");
                        });

                        // https://stackoverflow.com/questions/39573721/disable-round-robin-pattern-and-use-fanout-on-masstransit
                        cfg.ReceiveEndpoint(host, "dotnetgigs" + Guid.NewGuid().ToString(), e =>
                        {
                            e.LoadFrom(context);
                            //e.Consumer<ApplicantAppliedConsumer>();
                        });
                    });

                    return busControl;
                })
                .SingleInstance()
                .As<IBusControl>()
                .As<IBus>();

            builder.Populate(services);
            ApplicationContainer = builder.Build();
            return new AutofacServiceProvider(ApplicationContainer);
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public async void Configure(IApplicationBuilder app, IHostingEnvironment env, IServiceProvider serviceProvider, IApplicationLifetime lifetime)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseMvc();

            // stash an applicant's user data in redis for test purposes...this would simulate establishing auth/session in the real world
            var identityRepository=serviceProvider.GetService<IIdentityRepository>();
            await identityRepository.UpdateUserAsync(new User {Id = "1", Email = "josh903902@gmail.com",Name = "Josh Dillinger"});

            var bus = ApplicationContainer.Resolve<IBusControl>();
            var busHandle = TaskUtil.Await(() => bus.StartAsync());
            lifetime.ApplicationStopping.Register(() => busHandle.Stop());
        }
    }
}