Dapr

using Common;
using CountryPull;
using Dapr.Client;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

await Host.CreateDefaultBuilder(args).ConfigureServices((context, services) =>
{
    services.AddSingleton(provider => new DaprClientBuilder().Build());
    services.AddDbContext<AppleSystemStatusDbContext>(configuration => configuration.UseSqlServer(context.Configuration.GetConnectionString("Database")).UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking));
    services.Configure<Settings>(context.Configuration.GetSection(nameof(Settings)));
    services.AddHostedService<Worker>();
}).Build().RunAsync();

record Settings(string ChannelName, string TopicName);

using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Common;
using Dapr.Client;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;

namespace CountryPull
{
    public class Worker : BackgroundService
    {
        private readonly AppleSystemStatusDbContext context;
        private readonly DaprClient client;
        private readonly Settings settings;

        internal Worker(AppleSystemStatusDbContext context, DaprClient client, IOptions<Settings> settings)
        {
            this.context = context;
            this.client = client;
            this.settings = settings.Value;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            if (stoppingToken.IsCancellationRequested)
            {
                return;
            }

            var countries = await context.Countries.Select(country => country.Id).ToListAsync(stoppingToken);

            await Task.WhenAll(countries.Select(country => client.PublishEventAsync(settings.ChannelName, settings.TopicName, country, stoppingToken)));
        }
    }
}