InventoryAgent/Inventory.Agent/Program.cs

using Inventory.Core;
using Microsoft.Extensions.Configuration;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace Inventory.Agent
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var host = CreateHostBuilder(args).Build();
            host.Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args)
        {
            return Host.CreateDefaultBuilder(args)
                  .UseWindowsService() // This needs to be configured for Windows Services
                  .ConfigureAppConfiguration((context, config) =>
                  {
                      // Setup secrets here, after the default configuration and environment are established.
                      // This ensures Secrets are populated before ConfigureServices is called.
                      EnvironmentBuilder.SetupEnvironment(context.HostingEnvironment);
                  })
                  .ConfigureServices((context, services) =>
                  {
                      var dbCon = Secrets.DbConnectionString;
                      if (string.IsNullOrWhiteSpace(dbCon))
                      {
                          // Use a logger or console write if appropriate, but throwing is safer for startup.
                          throw new InvalidOperationException("DB_CONNECTION_STRING is not configured. The application cannot start. Ensure it is in your .env file or Vault.");
                      }

                      services.AddDbContext<InventoryContext>(options => options.UseSqlServer(dbCon));

                      services.AddHttpClient();
                      services.AddSingleton<SystemInfoCollector>();
                      services.AddScoped<DatabaseUpdater>();
                      services.AddScoped<HealthMonitor>();
                      services.AddScoped<SlurpitClient>();
                      services.AddScoped<UpdateWorkflow>();
                      services.AddHostedService<Worker>();
                  });
        }
    }
}