Merging Startup.cs and Program.cs in .NET 8: A Simplified Approach

using Microsoft.Extensions.Configuration.AzureAppConfiguration;
using Microsoft.Extensions.Logging.ApplicationInsights;
using System.Diagnostics;

public class Program
{
    public static void Main(string[] args)
    {
        try
        {
            Debug.WriteLine("Configure infrastructure...");
            BuildHost(args).Run();
        }
        catch (Exception ex)
        {
            Debug.WriteLine($"Infrastructure configuration failed: {ex}");
        }
    }

    public static IHost BuildHost(string[] args)
    {
        // Configuration and host building logic
    }
}

using Microsoft.AspNetCore.Http.Features;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using Microsoft.FeatureManagement;
using System.Diagnostics;

public class Startup
{
    public Startup(IConfiguration configuration, IWebHostEnvironment webHostEnvironment)
    {
        Configuration = configuration;
        WebHostEnvironment = webHostEnvironment;
    }

    public IConfiguration Configuration { get; }
    public IWebHostEnvironment WebHostEnvironment { get; }

    // Methods for configuring services and middleware
}

using Microsoft.AspNetCore.Http.Features;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration.AzureAppConfiguration;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.ApplicationInsights;
using Microsoft.FeatureManagement;
using Newtonsoft.Json.Converters;
using System.Diagnostics;

var builder = WebApplication.CreateBuilder(args);

// Configuration setup
// Using builder.Configuration to setup configuration sources
builder.Configuration.AddAzureAppConfiguration(options =>
{
    options.UseFeatureFlags(o =>
    {
        o.Label = "InstanceName"; // Replace with your instance name
        o.CacheExpirationInterval = TimeSpan.FromMinutes(10);
    });
    options.ConfigureKeyVault(o =>
    {
        o.SetCredential(new DefaultAzureCredential()); // Replace with your Azure credential
        o.SetSecretRefreshInterval(TimeSpan.FromMinutes(30));
    });
    options.Connect("YourAppConfigurationEndpoint", new DefaultAzureCredential()) // Replace with your endpoint and credential
        .ConfigureRefresh(o =>
        {
            o.Register("Settings:Sentinel", refreshAll: true)
               .SetCacheExpiration(TimeSpan.FromMinutes(10));
        })
        .Select(KeyFilter.Any, LabelFilter.Null)
        .Select(KeyFilter.Any, labelFilter: "InstanceName"); // Replace with your instance name
});

if (builder.Environment.IsDevelopment())
{
    builder.Configuration.AddJsonFile("appsettings.json", optional: true);
    builder.Configuration.AddUserSecrets<Program>();
}

builder.Configuration.AddEnvironmentVariables();

// Logging setup
// Using builder.Logging to setup logging providers
builder.Logging.ClearProviders(); // Clear default providers
builder.Logging.AddConsole(); // Add console logging
builder.Logging.AddDebug(); // Add debug logging
builder.Logging.AddAzureWebAppDiagnostics(); // Add Azure diagnostics

if (!builder.Environment.IsDevelopment() && Environment.GetEnvironmentVariable("AUTOMATED_TESTING") is null)
{
    builder.Logging.AddApplicationInsights(config =>
    {
        config.ConnectionString = builder.Configuration["APPLICATIONINSIGHTS_CONNECTION_STRING"];
        config.DisableTelemetry = false;
    }, options => options.IncludeScopes = false);
}

// Services setup
var services = builder.Services;
services.AddControllers().AddNewtonsoftJson(opt => opt.SerializerSettings.Converters.Add(new StringEnumConverter()));
services.AddDbContext<YourDbContext>(options => options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));
services.AddFeatureManagement();
services.AddAzureAppConfiguration();
// Register other services as needed

// Middleware setup
var app = builder.Build();

app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.MapControllers();

app.Run();

// Utility methods for retrieving services
private static T GetService<T>(IServiceCollection services)
{
    ServiceProvider serviceProvider = services.BuildServiceProvider();
    return serviceProvider.GetService<T>() ?? throw new Exception($"Could not find service {typeof(T)}");
}

private static T GetService<T>(IApplicationBuilder app)
{
    return app.ApplicationServices.GetService<T>() ?? throw new Exception($"Could not find service {typeof(T)}");
}

private static void DebugWrite(string message)
{
    Console.WriteLine(message);
    Debug.WriteLine(message);
}