Application.cs

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using System;
using System.Collections.Frozen;
using System.Collections.Generic;
using System.Globalization;
using System.IO.Abstractions;
using System.Threading.Tasks;
using System.Web;
 
using Cyberboss.AspNetCore.AsyncInitializer;
 
using Elastic.CommonSchema.Serilog;
 
using HotChocolate.AspNetCore;
 
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Authentication.OpenIdConnect;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Cors.Infrastructure;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Connections;
using Microsoft.AspNetCore.HttpOverrides;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc.Infrastructure;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Protocols.OpenIdConnect;
 
using Newtonsoft.Json;
 
using Prometheus;
 
using Serilog;
using Serilog.Events;
using Serilog.Formatting.Display;
using Serilog.Sinks.Elasticsearch;
 
using Tgstation.Server.Api;
using Tgstation.Server.Api.Hubs;
using Tgstation.Server.Api.Models;
using Tgstation.Server.Host.Authority;
using Tgstation.Server.Host.Authority.Core;
using Tgstation.Server.Host.Components;
using Tgstation.Server.Host.Components.Chat;
using Tgstation.Server.Host.Components.Deployment.Remote;
using Tgstation.Server.Host.Components.Engine;
using Tgstation.Server.Host.Components.Events;
using Tgstation.Server.Host.Components.Interop;
using Tgstation.Server.Host.Components.Interop.Bridge;
using Tgstation.Server.Host.Components.Repository;
using Tgstation.Server.Host.Components.Session;
using Tgstation.Server.Host.Components.Watchdog;
using Tgstation.Server.Host.Configuration;
using Tgstation.Server.Host.Controllers;
using Tgstation.Server.Host.Controllers.Results;
using Tgstation.Server.Host.Database;
using Tgstation.Server.Host.Extensions;
using Tgstation.Server.Host.GraphQL.Subscriptions;
using Tgstation.Server.Host.IO;
using Tgstation.Server.Host.Jobs;
using Tgstation.Server.Host.Properties;
using Tgstation.Server.Host.Security;
using Tgstation.Server.Host.Security.OAuth;
using Tgstation.Server.Host.Setup;
using Tgstation.Server.Host.Swarm;
using Tgstation.Server.Host.System;
using Tgstation.Server.Host.Transfer;
using Tgstation.Server.Host.Utils;
using Tgstation.Server.Shared;
 
namespace Tgstation.Server.Host.Core
{
#pragma warning disable CA1506
    public sealed class Application : SetupApplication
    {
        readonly IWebHostEnvironment hostingEnvironment;
 
        ITokenFactory? tokenFactory;
 
        public static IServerFactory CreateDefaultServerFactory()
        {
            var assemblyInformationProvider = new AssemblyInformationProvider();
            var fileSystem = new FileSystem();
            var ioManager = new DefaultIOManager(fileSystem);
            return new ServerFactory(
                assemblyInformationProvider,
                ioManager,
                fileSystem);
        }
 
        static void AddWatchdog<TSystemWatchdogFactory>(IServiceCollection services, IPostSetupServices postSetupServices)
            where TSystemWatchdogFactory : class, IWatchdogFactory
        {
            if (postSetupServices.GeneralConfiguration.UseBasicWatchdog)
                services.AddSingleton<IWatchdogFactory, WatchdogFactory>();
            else
                services.AddSingleton<IWatchdogFactory, TSystemWatchdogFactory>();
        }
 
        static string GetOidcScheme(string schemeKey)
            => AuthenticationContextFactory.OpenIDConnectAuthenticationSchemePrefix + schemeKey;
 
        public Application(
            IConfiguration configuration,
            IWebHostEnvironment hostingEnvironment)
            : base(configuration)
        {
            this.hostingEnvironment = hostingEnvironment ?? throw new ArgumentNullException(nameof(hostingEnvironment));
        }
 
        public void ConfigureServices(
            IServiceCollection services,
            IAssemblyInformationProvider assemblyInformationProvider,
            IIOManager ioManager,
            IPostSetupServices postSetupServices,
            IFileSystem fileSystem)
        {
            ConfigureServices(services, assemblyInformationProvider, ioManager);
 
            ArgumentNullException.ThrowIfNull(postSetupServices);
 
            // configure configuration
            services.UseStandardConfig<UpdatesConfiguration>(Configuration);
            services.UseStandardConfig<ControlPanelConfiguration>(Configuration);
            services.UseStandardConfig<SwarmConfiguration>(Configuration);
            services.UseStandardConfig<SessionConfiguration>(Configuration);
 
            // enable options which give us config reloading
            services.AddOptions();
 
            // Set the timeout for IHostedService.StopAsync
            services.Configure<HostOptions>(
                opts => opts.ShutdownTimeout = TimeSpan.FromMinutes(postSetupServices.GeneralConfiguration.RestartTimeoutMinutes));
 
            static LogEventLevel? ConvertSeriLogLevel(LogLevel logLevel) =>
                logLevel switch
                {
                    LogLevel.Critical => LogEventLevel.Fatal,
                    LogLevel.Debug => LogEventLevel.Debug,
                    LogLevel.Error => LogEventLevel.Error,
                    LogLevel.Information => LogEventLevel.Information,
                    LogLevel.Trace => LogEventLevel.Verbose,
                    LogLevel.Warning => LogEventLevel.Warning,
                    LogLevel.None => null,
                    _ => throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture, "Invalid log level {0}", logLevel)),
                };
 
            var microsoftEventLevel = ConvertSeriLogLevel(postSetupServices.FileLoggingConfiguration.MicrosoftLogLevel);
            var elasticsearchConfiguration = postSetupServices.ElasticsearchConfiguration;
            services.SetupLogging(
                config =>
                {
                    if (microsoftEventLevel.HasValue)
                    {
                        config.MinimumLevel.Override("Microsoft", microsoftEventLevel.Value);
                        config.MinimumLevel.Override("System.Net.Http.HttpClient", microsoftEventLevel.Value);
                    }
                },
                sinkConfig =>
                {
                    if (postSetupServices.FileLoggingConfiguration.Disable)
                        return;
 
                    var logPath = postSetupServices.FileLoggingConfiguration.GetFullLogDirectory(
                        ioManager,
                        assemblyInformationProvider,
                        postSetupServices.PlatformIdentifier);
 
                    var logEventLevel = ConvertSeriLogLevel(postSetupServices.FileLoggingConfiguration.LogLevel);
 
                    var formatter = new MessageTemplateTextFormatter(
                        "{Timestamp:o} "
                        + SerilogContextHelper.Template
                        + "): [{Level:u3}] {SourceContext:l}: {Message} ({EventId:x8}){NewLine}{Exception}",
                        null);
 
                    logPath = ioManager.ConcatPath(logPath, "tgs-.log");
                    var rollingFileConfig = sinkConfig.File(
                        formatter,
                        logPath,
                        logEventLevel ?? LogEventLevel.Verbose,
                        50 * 1024 * 1024, // 50MB max size
                        flushToDiskInterval: TimeSpan.FromSeconds(2),
                        rollingInterval: RollingInterval.Day,
                        rollOnFileSizeLimit: true);
                },
                elasticsearchConfiguration.Enable
                    ? new ElasticsearchSinkOptions(elasticsearchConfiguration.Host ?? throw new InvalidOperationException($"Missing {ElasticsearchConfiguration.Section}:{nameof(elasticsearchConfiguration.Host)}!"))
                    {
                        // Yes I know this means they cannot use a self signed cert unless they also have authentication, but lets be real here
                        // No one is going to be doing one of those but not the other
                        ModifyConnectionSettings = connectionConfigration => (!String.IsNullOrWhiteSpace(elasticsearchConfiguration.Username) && !String.IsNullOrWhiteSpace(elasticsearchConfiguration.Password))
                            ? connectionConfigration
                                .BasicAuthentication(
                                    elasticsearchConfiguration.Username,
                                    elasticsearchConfiguration.Password)
                                .ServerCertificateValidationCallback((o, certificate, chain, errors) => true)
                            : null,
                        CustomFormatter = new EcsTextFormatter(),
                        AutoRegisterTemplate = true,
                        AutoRegisterTemplateVersion = AutoRegisterTemplateVersion.ESv7,
                        IndexFormat = "tgs-logs",
                    }
                    : null,
                postSetupServices.InternalConfiguration,
                postSetupServices.FileLoggingConfiguration);
 
            // configure authentication pipeline
            ConfigureAuthenticationPipeline(services, postSetupServices.SecurityConfiguration);
 
            // add mvc, configure the json serializer settings
            var jsonVersionConverterList = new List<JsonConverter>
            {
                new VersionConverter(),
            };
 
            void ConfigureNewtonsoftJsonSerializerSettingsForApi(JsonSerializerSettings settings)
            {
                settings.NullValueHandling = NullValueHandling.Ignore;
                settings.CheckAdditionalContent = true;
                settings.MissingMemberHandling = MissingMemberHandling.Error;
                settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                settings.Converters = jsonVersionConverterList;
            }
 
            services
                .AddMvc(options =>
                {
                    options.ReturnHttpNotAcceptable = true;
                    options.RespectBrowserAcceptHeader = true;
                })
                .AddNewtonsoftJson(options =>
                {
                    options.AllowInputFormatterExceptionMessages = true;
                    ConfigureNewtonsoftJsonSerializerSettingsForApi(options.SerializerSettings);
                });
 
            services.AddSignalR(
                options =>
                {
                    options.AddFilter<AuthorizationContextHubFilter>();
                })
                .AddNewtonsoftJsonProtocol(options =>
                {
                    ConfigureNewtonsoftJsonSerializerSettingsForApi(options.PayloadSerializerSettings);
                });
 
            services.AddHub<JobsHub, IJobsHub>();
 
            if (postSetupServices.GeneralConfiguration.HostApiDocumentation)
            {
                string GetDocumentationFilePath(string assemblyLocation) => ioManager.ConcatPath(ioManager.GetDirectoryName(assemblyLocation), String.Concat(ioManager.GetFileNameWithoutExtension(assemblyLocation), ".xml"));
                var assemblyDocumentationPath = GetDocumentationFilePath(GetType().Assembly.Location);
                var apiDocumentationPath = GetDocumentationFilePath(typeof(ApiHeaders).Assembly.Location);
                services.AddSwaggerGen(genOptions => SwaggerConfiguration.Configure(genOptions, assemblyDocumentationPath, apiDocumentationPath));
                services.AddSwaggerGenNewtonsoftSupport();
            }
 
            // CORS conditionally enabled later
            services.AddCors();
 
            // Enable managed HTTP clients
            services
                .AddHttpClient()
                .ConfigureHttpClientDefaults(
                    builder => builder.ConfigureHttpClient(
                        client => client.DefaultRequestHeaders.UserAgent.Add(
                            assemblyInformationProvider.ProductInfoHeaderValue)));
 
            // configure metrics
            var prometheusPort = postSetupServices.GeneralConfiguration.PrometheusPort;
 
            services.AddSingleton<IMetricFactory>(_ => Metrics.DefaultFactory);
            services.AddSingleton<ICollectorRegistry>(_ => Metrics.DefaultRegistry);
 
            if (prometheusPort.HasValue && prometheusPort != postSetupServices.GeneralConfiguration.ApiPort)
                services.AddMetricServer(options => options.Port = prometheusPort.Value);
 
            services.UseHttpClientMetrics();
 
            var healthChecksBuilder = services
                .AddHealthChecks()
                .ForwardToPrometheus();
 
            // configure graphql
            services
                .AddScoped<ITopicEventReceiver, ShutdownAwareTopicEventReceiver>()
                .AddGraphQLServer()
                .ConfigureGraphQLServer();
 
            void AddTypedContext<TContext>()
                where TContext : DatabaseContext
            {
                var configureAction = DatabaseContext.GetConfigureAction<TContext>();
 
                services.AddDbContextPool<TContext>((serviceProvider, builder) =>
                {
                    if (hostingEnvironment.IsDevelopment())
                        builder.EnableSensitiveDataLogging();
 
                    var databaseConfigOptions = serviceProvider.GetRequiredService<IOptions<DatabaseConfiguration>>();
                    var databaseConfig = databaseConfigOptions.Value ?? throw new InvalidOperationException("DatabaseConfiguration missing!");
                    configureAction(builder, databaseConfig);
                });
                services.AddScoped<IDatabaseContext>(x => x.GetRequiredService<TContext>());
 
                healthChecksBuilder
                    .AddDbContextCheck<TContext>();
            }
 
            // add the correct database context type
            var dbType = postSetupServices.DatabaseConfiguration.DatabaseType;
            switch (dbType)
            {
                case DatabaseType.MySql:
                case DatabaseType.MariaDB:
                    AddTypedContext<MySqlDatabaseContext>();
                    break;
                case DatabaseType.SqlServer:
                    AddTypedContext<SqlServerDatabaseContext>();
                    break;
                case DatabaseType.Sqlite:
                    AddTypedContext<SqliteDatabaseContext>();
                    break;
                case DatabaseType.PostgresSql:
                    AddTypedContext<PostgresSqlDatabaseContext>();
                    break;
                default:
                    throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture, "Invalid {0}: {1}!", nameof(DatabaseType), dbType));
            }
 
            // configure other database services
            services.AddSingleton<IDatabaseContextFactory, DatabaseContextFactory>();
            services.AddSingleton<IDatabaseSeeder, DatabaseSeeder>();
 
            // configure other security services
            services.AddScoped<IOAuthProviders, OAuthProviders>();
            services.AddSingleton<IIdentityCache, IdentityCache>();
            services.AddSingleton<ICryptographySuite, CryptographySuite>();
            services.AddSingleton<ITokenFactory, TokenFactory>();
            services.AddSingleton<ISessionInvalidationTracker, SessionInvalidationTracker>();
            services.AddSingleton<IPasswordHasher<Models.User>, PasswordHasher<Models.User>>();
 
            // configure platform specific services
            if (postSetupServices.PlatformIdentifier.IsWindows)
            {
                AddWatchdog<WindowsWatchdogFactory>(services, postSetupServices);
                services.AddSingleton<ISystemIdentityFactory, WindowsSystemIdentityFactory>();
                services.AddSingleton<IFilesystemLinkFactory, WindowsFilesystemLinkFactory>();
                services.AddSingleton<ByondInstallerBase, WindowsByondInstaller>();
                services.AddSingleton<OpenDreamInstaller, WindowsOpenDreamInstaller>();
                services.AddSingleton<IPostWriteHandler, WindowsPostWriteHandler>();
                services.AddSingleton<IProcessFeatures, WindowsProcessFeatures>();
 
                services.AddSingleton<WindowsNetworkPromptReaper>();
                services.AddSingleton<INetworkPromptReaper>(x => x.GetRequiredService<WindowsNetworkPromptReaper>());
                services.AddSingleton<IHostedService>(x => x.GetRequiredService<WindowsNetworkPromptReaper>());
            }
            else
            {
                AddWatchdog<PosixWatchdogFactory>(services, postSetupServices);
                services.AddSingleton<ISystemIdentityFactory, PosixSystemIdentityFactory>();
                services.AddSingleton<IFilesystemLinkFactory, PosixFilesystemLinkFactory>();
                services.AddSingleton<ByondInstallerBase, PosixByondInstaller>();
                services.AddSingleton<OpenDreamInstaller>();
                services.AddSingleton<IPostWriteHandler, PosixPostWriteHandler>();
 
                services.AddSingleton<IProcessFeatures, PosixProcessFeatures>();
                services.AddHostedService<PosixProcessFeatures>();
 
                // PosixProcessFeatures also needs a IProcessExecutor for gcore
                services.AddSingleton(x => new Lazy<IProcessExecutor>(() => x.GetRequiredService<IProcessExecutor>(), true));
                services.AddSingleton<INetworkPromptReaper, PosixNetworkPromptReaper>();
 
                services.AddHostedService<PosixSignalHandler>();
            }
 
            // only global repo manager should be for the OD repo
            // god help me if we need more
            var openDreamRepositoryDirectory = ioManager.ConcatPath(
                ioManager.GetPathInLocalDirectory(assemblyInformationProvider),
                "OpenDreamRepository");
            services.AddSingleton(
                services => services
                    .GetRequiredService<IRepositoryManagerFactory>()
                    .CreateRepositoryManager(
                        services.GetRequiredService<IIOManager>().CreateResolverForSubdirectory(
                            openDreamRepositoryDirectory),
                        new NoopEventConsumer()));
 
            services.AddSingleton(
                serviceProvider => new Dictionary<EngineType, IEngineInstaller>
                {
                    { EngineType.Byond, serviceProvider.GetRequiredService<ByondInstallerBase>() },
                    { EngineType.OpenDream, serviceProvider.GetRequiredService<OpenDreamInstaller>() },
                }
                .ToFrozenDictionary());
            services.AddSingleton<IEngineInstaller, DelegatingEngineInstaller>();
 
            if (postSetupServices.InternalConfiguration.UsingSystemD)
                services.AddHostedService<SystemDManager>();
 
            // configure file transfer services
            services.AddSingleton<FileTransferService>();
            services.AddSingleton<IFileTransferStreamHandler>(x => x.GetRequiredService<FileTransferService>());
            services.AddSingleton<IFileTransferTicketProvider>(x => x.GetRequiredService<FileTransferService>());
            services.AddTransient<IActionResultExecutor<LimitedStreamResult>, LimitedStreamResultExecutor>();
 
            // configure swarm service
            services.AddSingleton<SwarmService>();
            services.AddSingleton<ISwarmService>(x => x.GetRequiredService<SwarmService>());
            services.AddSingleton<ISwarmOperations>(x => x.GetRequiredService<SwarmService>());
            services.AddSingleton<ISwarmServiceController>(x => x.GetRequiredService<SwarmService>());
 
            // configure component services
            services.AddSingleton<IPortAllocator, PortAllocator>();
            services.AddSingleton<IInstanceFactory, InstanceFactory>();
            services.AddSingleton<IGitRemoteFeaturesFactory, GitRemoteFeaturesFactory>();
            services.AddSingleton<ILibGit2RepositoryFactory, LibGit2RepositoryFactory>();
            services.AddSingleton<ILibGit2Commands, LibGit2Commands>();
            services.AddSingleton<IRepositoryManagerFactory, RepostoryManagerFactory>();
            services.AddSingleton<IRemoteDeploymentManagerFactory, RemoteDeploymentManagerFactory>();
            services.AddChatProviderFactory();
            services.AddSingleton<IChatManagerFactory, ChatManagerFactory>();
            services.AddSingleton<IServerUpdater, ServerUpdater>();
            services.AddSingleton<IServerUpdateInitiator, ServerUpdateInitiator>();
            services.AddSingleton<IDotnetDumpService, DotnetDumpService>();
 
            // configure authorities
            services.AddScoped(typeof(IRestAuthorityInvoker<>), typeof(RestAuthorityInvoker<>));
            services.AddScoped(typeof(IGraphQLAuthorityInvoker<>), typeof(GraphQLAuthorityInvoker<>));
            services.AddScoped<ILoginAuthority, LoginAuthority>();
            services.AddScoped<IUserAuthority, UserAuthority>();
            services.AddScoped<IUserGroupAuthority, UserGroupAuthority>();
            services.AddScoped<IPermissionSetAuthority, PermissionSetAuthority>();
            services.AddScoped<IAdministrationAuthority, AdministrationAuthority>();
            services.AddScoped<IChatAuthority, ChatAuthority>();
 
            // configure misc services
            services.AddSingleton<IProcessExecutor, ProcessExecutor>();
            services.AddSingleton<ISynchronousIOManager, SynchronousIOManager>();
            services.AddSingleton<IServerPortProvider, ServerPortProivder>();
            services.AddSingleton<ITopicClientFactory, TopicClientFactory>();
            services.AddSingleton(fileSystem);
            services.AddHostedService<CommandPipeManager>();
 
            services.AddFileDownloader();
            services.AddGitHub();
 
            // configure root services
            services.AddSingleton<JobService>();
            services.AddSingleton<IJobService>(provider => provider.GetRequiredService<JobService>());
            services.AddSingleton<IJobsHubUpdater>(provider => provider.GetRequiredService<JobService>());
            services.AddSingleton<IJobManager>(x => x.GetRequiredService<IJobService>());
            services.AddSingleton<JobsHubGroupMapper>();
            services.AddSingleton<IPermissionsUpdateNotifyee>(provider => provider.GetRequiredService<JobsHubGroupMapper>());
            services.AddSingleton<IHostedService>(x => x.GetRequiredService<JobsHubGroupMapper>()); // bit of a hack, but we need this to load immediated
 
            services.AddSingleton<InstanceManager>();
            services.AddSingleton<IBridgeDispatcher>(x => x.GetRequiredService<InstanceManager>());
            services.AddSingleton<IInstanceManager>(x => x.GetRequiredService<InstanceManager>());
        }
 
        public void Configure(
            IApplicationBuilder applicationBuilder,
            IServerControl serverControl,
            ITokenFactory tokenFactory,
            IServerPortProvider serverPortProvider,
            IAssemblyInformationProvider assemblyInformationProvider,
            IOptions<ControlPanelConfiguration> controlPanelConfigurationOptions,
            IOptions<GeneralConfiguration> generalConfigurationOptions,
            IOptions<DatabaseConfiguration> databaseConfigurationOptions,
            IOptions<SecurityConfiguration> securityConfigurationOptions,
            IOptions<SwarmConfiguration> swarmConfigurationOptions,
            IOptions<InternalConfiguration> internalConfigurationOptions,
            ILogger<Application> logger)
        {
            ArgumentNullException.ThrowIfNull(applicationBuilder);
            ArgumentNullException.ThrowIfNull(serverControl);
 
            this.tokenFactory = tokenFactory ?? throw new ArgumentNullException(nameof(tokenFactory));
 
            ArgumentNullException.ThrowIfNull(serverPortProvider);
            ArgumentNullException.ThrowIfNull(assemblyInformationProvider);
 
            var controlPanelConfiguration = (controlPanelConfigurationOptions ?? throw new ArgumentNullException(nameof(controlPanelConfigurationOptions))).Value;
            var generalConfiguration = (generalConfigurationOptions ?? throw new ArgumentNullException(nameof(generalConfigurationOptions))).Value;
            var databaseConfiguration = (databaseConfigurationOptions ?? throw new ArgumentNullException(nameof(databaseConfigurationOptions))).Value;
            var swarmConfiguration = (swarmConfigurationOptions ?? throw new ArgumentNullException(nameof(swarmConfigurationOptions))).Value;
            var internalConfiguration = (internalConfigurationOptions ?? throw new ArgumentNullException(nameof(internalConfigurationOptions))).Value;
 
            ArgumentNullException.ThrowIfNull(logger);
 
            logger.LogDebug("Database provider: {provider}", databaseConfiguration.DatabaseType);
            logger.LogDebug("Content Root: {contentRoot}", hostingEnvironment.ContentRootPath);
            logger.LogTrace("Web Root: {webRoot}", hostingEnvironment.WebRootPath);
 
            // setup the HTTP request pipeline
            // Add additional logging context to the request
            applicationBuilder.UseAdditionalRequestLoggingContext(swarmConfiguration);
 
            // Wrap exceptions in a 500 (ErrorMessage) response
            applicationBuilder.UseServerErrorHandling();
 
            // header forwarding important for OIDC
            var forwardedHeaderOptions = new ForwardedHeadersOptions
            {
                ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto | ForwardedHeaders.XForwardedHost,
            };
 
            forwardedHeaderOptions.KnownNetworks.Clear();
            forwardedHeaderOptions.KnownNetworks.Add(
                new IPNetwork(
                    global::System.Net.IPAddress.Any,
                    0));
 
            applicationBuilder.UseForwardedHeaders(forwardedHeaderOptions);
 
            // metrics capture
            applicationBuilder.UseHttpMetrics();
 
            // Add the X-Powered-By response header
            applicationBuilder.UseServerBranding(assemblyInformationProvider);
 
            // Add the X-Accel-Buffering response header
            applicationBuilder.UseDisabledNginxProxyBuffering();
 
            // suppress OperationCancelledExceptions, they are just aborted HTTP requests
            applicationBuilder.UseCancelledRequestSuppression();
 
            // 503 requests made while the application is starting
            applicationBuilder.UseAsyncInitialization<IInstanceManager>(
                (instanceManager, cancellationToken) => instanceManager.Ready.WaitAsync(cancellationToken));
 
            if (generalConfiguration.HostApiDocumentation)
            {
                var siteDocPath = Routes.ApiRoot + $"doc/{SwaggerConfiguration.DocumentName}.json";
                if (!String.IsNullOrWhiteSpace(controlPanelConfiguration.PublicPath))
                    siteDocPath = controlPanelConfiguration.PublicPath.TrimEnd('/') + siteDocPath;
 
                applicationBuilder.UseSwagger(options =>
                {
                    options.RouteTemplate = Routes.ApiRoot + "doc/{documentName}.{json|yaml}";
                });
                applicationBuilder.UseSwaggerUI(options =>
                {
                    options.RoutePrefix = SwaggerConfiguration.DocumentationSiteRouteExtension;
                    options.SwaggerEndpoint(siteDocPath, "TGS API");
                });
                logger.LogTrace("Swagger API generation enabled");
            }
 
            // spa loading if necessary
            if (controlPanelConfiguration.Enable)
            {
                logger.LogInformation("Web control panel enabled.");
                applicationBuilder.UseFileServer(new FileServerOptions
                {
                    RequestPath = ControlPanelController.ControlPanelRoute,
                    EnableDefaultFiles = true,
                    EnableDirectoryBrowsing = false,
                    RedirectToAppendTrailingSlash = false,
                });
            }
            else
#if NO_WEBPANEL
                logger.LogDebug("Web control panel was not included in TGS build!");
#else
                logger.LogTrace("Web control panel disabled!");
#endif
 
            // Enable endpoint routing
            applicationBuilder.UseRouting();
 
            // Set up CORS based on configuration if necessary
            Action<CorsPolicyBuilder>? corsBuilder = null;
            if (controlPanelConfiguration.AllowAnyOrigin)
            {
                logger.LogTrace("Access-Control-Allow-Origin: *");
                corsBuilder = builder => builder.SetIsOriginAllowed(_ => true);
            }
            else if (controlPanelConfiguration.AllowedOrigins?.Count > 0)
            {
                logger.LogTrace("Access-Control-Allow-Origin: {allowedOrigins}", String.Join(',', controlPanelConfiguration.AllowedOrigins));
                corsBuilder = builder => builder.WithOrigins([.. controlPanelConfiguration.AllowedOrigins]);
            }
 
            var originalBuilder = corsBuilder;
            corsBuilder = builder =>
            {
                builder
                    .AllowAnyHeader()
                    .AllowAnyMethod()
                    .AllowCredentials()
                    .SetPreflightMaxAge(TimeSpan.FromDays(1));
                originalBuilder?.Invoke(builder);
            };
            applicationBuilder.UseCors(corsBuilder);
 
            // validate the API version
            applicationBuilder.UseApiCompatibility();
 
            // authenticate JWT tokens using our security pipeline if present, returns 401 if bad
            applicationBuilder.UseAuthentication();
 
            // enable authorization on endpoints
            applicationBuilder.UseAuthorization();
 
            // suppress and log database exceptions
            applicationBuilder.UseDbConflictHandling();
 
            // setup endpoints
            applicationBuilder.UseEndpoints(endpoints =>
            {
                // access to the signalR jobs hub
                endpoints.MapHub<JobsHub>(
                    Routes.JobsHub,
                    options =>
                    {
                        options.Transports = HttpTransportType.ServerSentEvents;
                        options.CloseOnAuthenticationExpiration = true;
                    })
                    .RequireAuthorization()
                    .RequireCors(corsBuilder);
 
                // majority of handling is done in the controllers
                endpoints.MapControllers();
 
                if (internalConfiguration.EnableGraphQL)
                {
                    logger.LogWarning("Enabling GraphQL. This API is experimental and breaking changes may occur at any time!");
                    var gqlOptions = new GraphQLServerOptions
                    {
                        EnableBatching = true,
                    };
 
                    gqlOptions.Tool.Enable = generalConfiguration.HostApiDocumentation;
 
                    endpoints
                        .MapGraphQL(Routes.GraphQL)
                        .WithOptions(gqlOptions);
                }
 
                if (generalConfiguration.PrometheusPort.HasValue)
                    if (generalConfiguration.PrometheusPort == generalConfiguration.ApiPort)
                    {
                        endpoints.MapMetrics();
                        logger.LogDebug("Prometheus being hosted alongside server");
                    }
                    else
                        logger.LogDebug("Prometheus being hosted on port {prometheusPort}", generalConfiguration.PrometheusPort);
                else
                    logger.LogTrace("Prometheus disabled");
 
                endpoints.MapHealthChecks("/health");
 
                var oidcConfig = securityConfigurationOptions.Value.OpenIDConnect;
                if (oidcConfig == null)
                    return;
 
                foreach (var kvp in oidcConfig)
                    endpoints.MapGet(
                        $"/oidc/{kvp.Key}/signin",
                        context => context.ChallengeAsync(
                            GetOidcScheme(kvp.Key),
                            new AuthenticationProperties
                            {
                                RedirectUri = $"/oidc/{kvp.Key}/landing",
                            }));
            });
 
            // 404 anything that gets this far
            // End of request pipeline setup
            logger.LogTrace("Configuration version: {configVersion}", GeneralConfiguration.CurrentConfigVersion);
            logger.LogTrace("DMAPI Interop version: {interopVersion}", DMApiConstants.InteropVersion);
            if (controlPanelConfiguration.Enable)
                logger.LogTrace("Webpanel version: {webCPVersion}", MasterVersionsAttribute.Instance.RawWebpanelVersion);
 
            logger.LogDebug("Starting hosting on port {httpApiPort}...", serverPortProvider.HttpApiPort);
        }
 
        protected override void ConfigureHostedService(IServiceCollection services)
            => services.AddSingleton<IHostedService>(x => x.GetRequiredService<InstanceManager>());
 
        void ConfigureAuthenticationPipeline(IServiceCollection services, SecurityConfiguration securityConfiguration)
        {
            services.AddHttpContextAccessor();
            services.AddScoped<IApiHeadersProvider, ApiHeadersProvider>();
            services.AddScoped<AuthenticationContextFactory>();
            services.AddScoped<ITokenValidator>(provider => provider.GetRequiredService<AuthenticationContextFactory>());
 
            services.AddScoped<IClaimsPrincipalAccessor, ClaimsPrincipalAccessor>();
            services.AddScoped<Security.IAuthorizationService, AuthorizationService>();
            services.AddScoped<IAuthorizationHandler, AuthorizationHandler>();
 
            // what if you
            // wanted to just do this:
            // return provider.GetRequiredService<AuthenticationContextFactory>().CurrentAuthenticationContext
            // But M$ said
            // https://stackoverflow.com/questions/56792917/scoped-services-in-asp-net-core-with-signalr-hubs
            services.AddScoped(provider => (provider
                .GetRequiredService<IHttpContextAccessor>()
                .HttpContext ?? throw new InvalidOperationException($"Unable to resolve {nameof(IAuthenticationContext)} due to no HttpContext being available!"))
                .RequestServices
                .GetRequiredService<AuthenticationContextFactory>()
                .CurrentAuthenticationContext);
            services.AddScoped<IClaimsTransformation, AuthenticationContextClaimsTransformation>();
 
            var authBuilder = services
                .AddAuthentication(options =>
                {
                    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
                })
                .AddJwtBearer(jwtBearerOptions =>
                {
                    // this line isn't actually run until the first request is made
                    // at that point tokenFactory will be populated
                    jwtBearerOptions.TokenValidationParameters = tokenFactory?.ValidationParameters ?? throw new InvalidOperationException("tokenFactory not initialized!");
                    jwtBearerOptions.MapInboundClaims = false;
                    jwtBearerOptions.Events = new JwtBearerEvents
                    {
                        OnMessageReceived = context =>
                        {
                            if (String.IsNullOrWhiteSpace(context.Token))
                            {
                                var accessToken = context.Request.Query["access_token"];
                                var path = context.HttpContext.Request.Path;
 
                                if (!String.IsNullOrWhiteSpace(accessToken) &&
                                    path.StartsWithSegments(Routes.HubsRoot, StringComparison.OrdinalIgnoreCase))
                                {
                                    context.Token = accessToken;
                                }
                            }
 
                            return Task.CompletedTask;
                        },
                        OnTokenValidated = context => context
                            .HttpContext
                            .RequestServices
                            .GetRequiredService<ITokenValidator>()
                            .ValidateTgsToken(
                                context,
                                context
                                    .HttpContext
                                    .RequestAborted),
                    };
                });
 
            services.AddAuthorization(options =>
            {
                options.AddPolicy(
                    TgsAuthorizeAttribute.PolicyName,
                    builder => builder
                        .RequireAuthenticatedUser()
                        .RequireRole(TgsAuthorizeAttribute.UserEnabledRole));
 
                options.DefaultPolicy = options.GetPolicy(TgsAuthorizeAttribute.PolicyName)!;
            });
 
            var oidcConfig = securityConfiguration.OpenIDConnect;
            if (oidcConfig == null || oidcConfig.Count == 0)
                return;
 
            authBuilder.AddCookie(CookieAuthenticationDefaults.AuthenticationScheme);
 
            foreach (var kvp in oidcConfig)
            {
                var configName = kvp.Key;
                authBuilder
                    .AddOpenIdConnect(
                        GetOidcScheme(configName),
                        options =>
                        {
                            var config = kvp.Value;
 
                            options.Authority = config.Authority?.ToString();
                            options.ClientId = config.ClientId;
                            options.ClientSecret = config.ClientSecret;
 
                            options.Events = new OpenIdConnectEvents
                            {
                                OnRemoteFailure = context =>
                                {
                                    context.HandleResponse();
                                    context.HttpContext.Response.Redirect($"{config.ReturnPath}?error={HttpUtility.UrlEncode(context.Failure?.Message ?? $"{options.Events.OnRemoteFailure} was called without an {nameof(Exception)}!")}&state=oidc.{HttpUtility.UrlEncode(configName)}");
                                    return Task.CompletedTask;
                                },
                                OnTicketReceived = context =>
                                {
                                    var services = context
                                        .HttpContext
                                        .RequestServices;
                                    var tokenFactory = services
                                        .GetRequiredService<ITokenFactory>();
                                    var authenticationContext = services
                                        .GetRequiredService<IAuthenticationContext>();
                                    context.HandleResponse();
                                    context.HttpContext.Response.Redirect($"{config.ReturnPath}?code={HttpUtility.UrlEncode(tokenFactory.CreateToken(authenticationContext.User, true))}&state=oidc.{HttpUtility.UrlEncode(configName)}");
                                    return Task.CompletedTask;
                                },
                            };
 
                            Task CompleteAuth(RemoteAuthenticationContext<OpenIdConnectOptions> context)
                                => context
                                        .HttpContext
                                        .RequestServices
                                        .GetRequiredService<ITokenValidator>()
                                        .ValidateOidcToken(
                                            context,
                                            configName,
                                            config.GroupIdClaim,
                                            context
                                                .HttpContext
                                                .RequestAborted);
 
                            if (securityConfiguration.OidcStrictMode)
                            {
                                options.GetClaimsFromUserInfoEndpoint = true;
                                options.ClaimActions.MapUniqueJsonKey(config.GroupIdClaim, config.GroupIdClaim);
                                options.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters
                                {
                                    NameClaimType = config.UsernameClaim,
                                    RoleClaimType = "roles",
                                };
 
                                options.Scope.Add(OpenIdConnectScope.Profile);
                                options.Events.OnUserInformationReceived = CompleteAuth;
                            }
                            else
                                options.Events.OnTokenValidated = CompleteAuth;
 
                            options.Scope.Add(OpenIdConnectScope.OpenId);
                            options.Scope.Add(OpenIdConnectScope.OfflineAccess);
 
                            options.RequireHttpsMetadata = false;
                            options.SaveTokens = true;
                            options.ResponseType = OpenIdConnectResponseType.Code;
                            options.MapInboundClaims = false;
 
                            options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
 
                            var basePath = $"/oidc/{configName}/";
                            options.CallbackPath = new PathString(basePath + "signin-callback");
                            options.SignedOutCallbackPath = new PathString(basePath + "signout-callback");
                            options.RemoteSignOutPath = new PathString(basePath + "signout");
                        });
            }
        }
    }
}