messengerapi.Broker/code/MessengerBroker/Program.cs

using MessengerApi.Configuration.Sources.Environment;
using MessengerBroker.Configuration.Model;
using MessengerBroker.Factories;
using MessengerBroker.Handlers;
using MessengerBroker.Handlers.Endpoint;
using MessengerBroker.Model.Http;
using MessengerBroker.Models.Scoped;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.HttpOverrides;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Net;

namespace MessengerBroker
{
    public class Program
    {
        public static void Main(string[] args)
        {
            BrokerConfiguration configuration = null;

            try
            {
                configuration = new BrokerConfiguration(new EnvironmentConfigurationSource());
            }
            catch (Exception ex)
            {
                Console.WriteLine("Can't load settings.", ex);
                throw;
            }

            var builder = WebApplication.CreateBuilder(args);

            builder.Services.AddMemoryCache();
            builder.Services.AddSingleton<ILogger, ConsoleLogger>();
            builder.Services.AddSingleton<BrokerConfiguration>(configuration);
            builder.Services.AddSingleton<BrokerDbContextFactory>();
            builder.Services.AddSingleton<MessengerApi.Factories.DbContextFactory>((sp) =>
            {
                return new MessengerApi.Factories.DbContextFactory(configuration.ApiPersistenceConfiguration);
            });
            builder.Services.AddSingleton<HousekeepingHandler>();
            builder.Services.AddSingleton<MasterServerSynchronizationHandler>();

            builder.Services.AddScoped<Identity>();
            builder.Services.AddScoped<UsersEndpointHandler>();
            builder.Services.AddScoped<MessagesEndpointHandler>();

            // Authentication.
            builder.Services
                .AddAuthentication("Bearer")
                .AddScheme<AuthenticationSchemeOptions, CustomBearerAuthenticationHandler>("Bearer", null);

            // Proxy registration to forward real client IPs.
            builder.Services.Configure<ForwardedHeadersOptions>(options =>
            {
                options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;

                foreach (var proxy in configuration.Proxies)
                {
                    options.KnownProxies.Add(IPAddress.Parse(proxy));
                }
            });

            var app = builder.Build();

            // DB Migrations
            using (var ctx = app.Services.GetRequiredService<BrokerDbContextFactory>().CreateDbContext())
            {
                var migrationLogger = app.Services.GetRequiredService<ILogger>();

                try
                {
                    if (ctx.Database.GetPendingMigrations().Any())
                    {
                        migrationLogger.Info("Applying migrations.");
                        ctx.Database.Migrate();
                    }
                    else
                    {
                        migrationLogger.Info("No migrations pending.");
                    }
                }
                catch (Exception ex)
                {
                    migrationLogger.Error("Can't run migrations successfully.", ex);
                    throw;
                }
            }

            // Housekeeping.
            if (configuration.HousekeepingEnabled)
            {
                _ = app.Services.GetRequiredService<HousekeepingHandler>().BeginHousekeeping();
            }

            //// Run pull sync from masters.
            if(configuration.MasterServers.Any())
            {
                var handler = app.Services.GetRequiredService<MasterServerSynchronizationHandler>();
                var logger = app.Services.GetRequiredService<ILogger>();

                foreach (var server in configuration.MasterServers)
                {
                    logger.Info($"Starting sync task for {server}.");    
                    _ = handler.BeginSyncing(server);
                }
            }

            app.UseStaticFiles();
            app.UseRouting();
            app.UseAuthentication();
            app.UseForwardedHeaders();

            app.MapGet("/users", async (UsersEndpointHandler handler) =>
            {
                var response = await handler.GetUsers();
                return Results.Json(response);
            });

            app.MapGet("/messages", async (
                MessagesEndpointHandler handler, 
                [FromQuery] Guid ownerBrokerId, DateTime fromUtc) =>
            {
                var response = await handler.GetMessages(new Messages.MessagesRequest
                {
                    OwnerBrokerId = ownerBrokerId,
                    SinceUtc = DateTime.MinValue
                });
                return Results.Json(response);
            });

            app.Run();
        }
    }
}