Program.cs

using JustSaying.Sample.Restaurant.KitchenConsole;
using JustSaying.Sample.Restaurant.KitchenConsole.Handlers;
using JustSaying.Sample.Restaurant.Models;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Serilog;

const string appName = "KitchenConsole";

Log.Logger = new LoggerConfiguration()
    .WriteTo.Console()
    .MinimumLevel.Debug()
    .Enrich.WithProperty("AppName", appName)
    .CreateLogger();

Console.Title = appName;

try
{
    await Run();
}
catch (Exception e)
{
    Log.Fatal(e, "Error occurred during startup: {Message}", e.Message);
}
finally
{
    Log.CloseAndFlush();
}

static async Task Run()
{
    await new HostBuilder()
        .ConfigureAppConfiguration((hostContext, config) =>
        {
            config.AddJsonFile("appsettings.json", optional: false);
            config.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", optional: true);
            config.AddEnvironmentVariables();
        })
        .UseSerilog()
        .ConfigureServices((hostContext, services) =>
        {
            var configuration = hostContext.Configuration;
            services.AddJustSaying(config =>
            {
                config.Client(x =>
                {
                    if (configuration.HasAWSServiceUrl())
                    {
                        // The AWS client SDK allows specifying a custom HTTP endpoint.
                        // For testing purposes it is useful to specify a value that
                        // points to a docker image such as `localstack/localstack`
                        x.WithServiceUri(configuration.GetAWSServiceUri())
                            .WithAnonymousCredentials();
                    }
                    else
                    {
                        // The real AWS environment will require some means of authentication
                        //x.WithBasicCredentials("###", "###");
                        //x.WithSessionCredentials("###", "###", "###");
                    }
                });

                config.Messaging(x =>
                {
                    // Configures which AWS Region to operate in
                    x.WithRegion(configuration.GetAWSRegion());
                });

                config.Subscriptions(x =>
                {
                    x.WithSubscriptionGroup("GroupA",
                        c => c.WithPrefetch(10)
                            .WithMultiplexerCapacity(10)
                            .WithConcurrencyLimit(5));

                    // Creates the following if they do not already exist
                    //  - a SQS queue of name `orderplacedevent`
                    //  - a SQS queue of name `orderplacedevent_error`
                    //  - a SNS topic of name `orderplacedevent`
                    //  - a SNS topic subscription on topic 'orderplacedevent' and queue 'orderplacedevent' with two tags
                    //      - "IsOrderEvent" with no value
                    //      - "Subscriber" with the value "KitchenConsole"
                    //  - a SNS topic subscription on topic 'orderonitswayevent' and queue 'orderonitswayevent'
                    x.ForTopic<OrderPlacedEvent>(cfg =>
                        cfg.WithTag("IsOrderEvent")
                            .WithTag("Subscriber", appName)
                            .WithReadConfiguration(rc =>
                                rc.WithSubscriptionGroup("GroupA")));

                    x.ForTopic<OrderOnItsWayEvent>(cfg =>
                        cfg.WithReadConfiguration(rc =>
                            rc.WithSubscriptionGroup("GroupB")));
                });

                config.Publications(x =>
                {
                    // Creates the following if they do not already exist
                    //  - an SNS topic of name `orderreadyevent` with two tags:
                    //      - "IsOrderEvent" with no value
                    //      - "Publisher" with the value "KitchenConsole"
                    x.WithTopic<OrderReadyEvent>(cfg =>
                    {
                        cfg.WithTag("IsOrderEvent")
                            .WithTag("Publisher", appName);
                    });
                    x.WithTopic<OrderDeliveredEvent>();
                });
            });

            // Added a message handler for message type for 'OrderPlacedEvent' on topic 'orderplacedevent' and queue 'orderplacedevent'
            services.AddJustSayingHandler<OrderPlacedEvent, OrderPlacedEventHandler>();
            services.AddJustSayingHandler<OrderOnItsWayEvent, OrderOnItsWayEventHandler>();

            // Add a background service that is listening for messages related to the above subscriptions
            services.AddHostedService<Subscriber>();
        })
        .UseConsoleLifetime()
        .Build()
        .RunAsync();
}