public void GetHostIdAsync_IfStorageAccountProviderThrowsInvalidOperationException_WrapsException()
        {
            // Arrange
            Mock<IStorageAccountProvider> storageAccountProviderMock = new Mock<IStorageAccountProvider>(
                MockBehavior.Strict);
            TaskCompletionSource<IStorageAccount> taskSource = new TaskCompletionSource<IStorageAccount>();
            InvalidOperationException innerException = new InvalidOperationException();
            taskSource.SetException(innerException);
            storageAccountProviderMock
                .Setup(p => p.GetAccountAsync(It.IsAny<string>(), It.IsAny<CancellationToken>()))
                .Returns(taskSource.Task);
            IStorageAccountProvider storageAccountProvider = storageAccountProviderMock.Object;
            IFunctionIndexProvider functionIndexProvider = CreateDummyFunctionIndexProvider();

            IHostIdProvider product = new DynamicHostIdProvider(storageAccountProvider, () => functionIndexProvider);
            CancellationToken cancellationToken = CancellationToken.None;

            // Act & Assert
            InvalidOperationException exception = Assert.Throws<InvalidOperationException>(
                () => product.GetHostIdAsync(cancellationToken).GetAwaiter().GetResult());
            Assert.Equal("A host ID is required. Either set JobHostConfiguration.HostId or provide a valid storage " +
                "connection string.", exception.Message);
            Assert.Same(innerException, exception.InnerException);
        }
        public static async Task<JobHostContext> CreateAndLogHostStartedAsync(
            JobHost host,
            IStorageAccountProvider storageAccountProvider,
            IQueueConfiguration queueConfiguration,
            ITypeLocator typeLocator,
            IJobActivator activator,
            INameResolver nameResolver,
            IConsoleProvider consoleProvider,
            JobHostConfiguration config,
            CancellationToken shutdownToken,
            CancellationToken cancellationToken,
            IHostIdProvider hostIdProvider = null,
            FunctionExecutor functionExecutor = null,
            IFunctionIndexProvider functionIndexProvider = null,
            IBindingProvider bindingProvider = null,
            IHostInstanceLoggerProvider hostInstanceLogerProvider = null,
            IFunctionInstanceLoggerProvider functionInstanceLoggerProvider = null,
            IFunctionOutputLoggerProvider functionOutputLoggerProvider = null,
            IBackgroundExceptionDispatcher backgroundExceptionDispatcher = null,
            SingletonManager singletonManager = null)
        {
            if (hostIdProvider == null)
            {
                hostIdProvider = new DynamicHostIdProvider(storageAccountProvider, () => functionIndexProvider);
            }

            IExtensionTypeLocator extensionTypeLocator = new ExtensionTypeLocator(typeLocator);
            if (backgroundExceptionDispatcher == null)
            {
                backgroundExceptionDispatcher = BackgroundExceptionDispatcher.Instance;
            }
            ContextAccessor<IMessageEnqueuedWatcher> messageEnqueuedWatcherAccessor = new ContextAccessor<IMessageEnqueuedWatcher>();
            ContextAccessor<IBlobWrittenWatcher> blobWrittenWatcherAccessor = new ContextAccessor<IBlobWrittenWatcher>();
            ISharedContextProvider sharedContextProvider = new SharedContextProvider();

            // Create a wrapper TraceWriter that delegates to both the user 
            // TraceWriter specified on Config (if present), as well as to Console
            TraceWriter trace = new ConsoleTraceWriter(config.Tracing, consoleProvider.Out);

            // Register system services with the service container
            config.AddService<INameResolver>(nameResolver);

            ExtensionConfigContext context = new ExtensionConfigContext
            {
                Config = config,
                Trace = trace,
                Host = host
            };
            InvokeExtensionConfigProviders(context);

            IExtensionRegistry extensions = config.GetExtensions();
            ITriggerBindingProvider triggerBindingProvider = DefaultTriggerBindingProvider.Create(nameResolver,
                storageAccountProvider, extensionTypeLocator, hostIdProvider, queueConfiguration, backgroundExceptionDispatcher,
                messageEnqueuedWatcherAccessor, blobWrittenWatcherAccessor, sharedContextProvider, extensions, trace);

            if (bindingProvider == null)
            {
                bindingProvider = DefaultBindingProvider.Create(nameResolver, storageAccountProvider, extensionTypeLocator, messageEnqueuedWatcherAccessor, blobWrittenWatcherAccessor, extensions);
            }

            DefaultLoggerProvider loggerProvider = new DefaultLoggerProvider(storageAccountProvider, trace);

            if (singletonManager == null)
            {
                singletonManager = new SingletonManager(storageAccountProvider, backgroundExceptionDispatcher, config.Singleton, trace, config.NameResolver);
            }
            
            using (CancellationTokenSource combinedCancellationSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, shutdownToken))
            {
                CancellationToken combinedCancellationToken = combinedCancellationSource.Token;

                await WriteSiteExtensionManifestAsync(combinedCancellationToken);

                IStorageAccount dashboardAccount = await storageAccountProvider.GetDashboardAccountAsync(combinedCancellationToken);

                IHostInstanceLogger hostInstanceLogger = null;
                if (hostInstanceLogerProvider != null)
                {
                    hostInstanceLogger = await hostInstanceLogerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    hostInstanceLogger = await((IHostInstanceLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken);
                }

                IFunctionInstanceLogger functionInstanceLogger = null;
                if (functionInstanceLoggerProvider != null)
                {
                    functionInstanceLogger = await functionInstanceLoggerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    functionInstanceLogger = (IFunctionInstanceLogger)(await((IFunctionInstanceLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken));
                }

                IFunctionOutputLogger functionOutputLogger = null;
                if (functionOutputLoggerProvider != null)
                {
                    functionOutputLogger = await functionOutputLoggerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    functionOutputLogger = (IFunctionOutputLogger)(await((IFunctionOutputLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken));
                }

                if (functionExecutor == null)
                {
                    functionExecutor = new FunctionExecutor(functionInstanceLogger, functionOutputLogger, backgroundExceptionDispatcher, trace);
                }

                if (functionIndexProvider == null)
                {
                    functionIndexProvider = new FunctionIndexProvider(typeLocator, triggerBindingProvider, bindingProvider, activator, functionExecutor, extensions, singletonManager);
                }

                IFunctionIndex functions = await functionIndexProvider.GetAsync(combinedCancellationToken);
                IListenerFactory functionsListenerFactory = new HostListenerFactory(functions.ReadAll(), singletonManager, activator, nameResolver, trace);

                IFunctionExecutor hostCallExecutor;
                IListener listener;
                HostOutputMessage hostOutputMessage;

                if (dashboardAccount != null)
                {
                    string hostId = await hostIdProvider.GetHostIdAsync(cancellationToken);

                    string sharedQueueName = HostQueueNames.GetHostQueueName(hostId);
                    IStorageQueueClient dashboardQueueClient = dashboardAccount.CreateQueueClient();
                    IStorageQueue sharedQueue = dashboardQueueClient.GetQueueReference(sharedQueueName);
                    IListenerFactory sharedQueueListenerFactory = new HostMessageListenerFactory(sharedQueue,
                        queueConfiguration, backgroundExceptionDispatcher, trace, functions,
                        functionInstanceLogger, functionExecutor);

                    Guid hostInstanceId = Guid.NewGuid();
                    string instanceQueueName = HostQueueNames.GetHostQueueName(hostInstanceId.ToString("N"));
                    IStorageQueue instanceQueue = dashboardQueueClient.GetQueueReference(instanceQueueName);
                    IListenerFactory instanceQueueListenerFactory = new HostMessageListenerFactory(instanceQueue,
                        queueConfiguration, backgroundExceptionDispatcher, trace, functions,
                        functionInstanceLogger, functionExecutor);

                    HeartbeatDescriptor heartbeatDescriptor = new HeartbeatDescriptor
                    {
                        SharedContainerName = HostContainerNames.Hosts,
                        SharedDirectoryName = HostDirectoryNames.Heartbeats + "/" + hostId,
                        InstanceBlobName = hostInstanceId.ToString("N"),
                        ExpirationInSeconds = (int)HeartbeatIntervals.ExpirationInterval.TotalSeconds
                    };

                    IStorageBlockBlob blob = dashboardAccount.CreateBlobClient()
                        .GetContainerReference(heartbeatDescriptor.SharedContainerName)
                        .GetBlockBlobReference(heartbeatDescriptor.SharedDirectoryName + "/" + heartbeatDescriptor.InstanceBlobName);
                    IRecurrentCommand heartbeatCommand = new UpdateHostHeartbeatCommand(new HeartbeatCommand(blob));

                    IEnumerable<MethodInfo> indexedMethods = functions.ReadAllMethods();
                    Assembly hostAssembly = GetHostAssembly(indexedMethods);
                    string displayName = hostAssembly != null ? hostAssembly.GetName().Name : "Unknown";

                    hostOutputMessage = new DataOnlyHostOutputMessage
                    {
                        HostInstanceId = hostInstanceId,
                        HostDisplayName = displayName,
                        SharedQueueName = sharedQueueName,
                        InstanceQueueName = instanceQueueName,
                        Heartbeat = heartbeatDescriptor,
                        WebJobRunIdentifier = WebJobRunIdentifier.Current
                    };

                    hostCallExecutor = CreateHostCallExecutor(instanceQueueListenerFactory, heartbeatCommand,
                        backgroundExceptionDispatcher, shutdownToken, functionExecutor);
                    IListenerFactory hostListenerFactory = new CompositeListenerFactory(functionsListenerFactory,
                        sharedQueueListenerFactory, instanceQueueListenerFactory);
                    listener = CreateHostListener(hostListenerFactory, heartbeatCommand, backgroundExceptionDispatcher, shutdownToken);

                    // Publish this to Azure logging account so that a web dashboard can see it. 
                    await LogHostStartedAsync(functions, hostOutputMessage, hostInstanceLogger, combinedCancellationToken);
                }
                else
                {
                    hostCallExecutor = new ShutdownFunctionExecutor(shutdownToken, functionExecutor);

                    IListener factoryListener = new ListenerFactoryListener(functionsListenerFactory);
                    IListener shutdownListener = new ShutdownListener(shutdownToken, factoryListener);
                    listener = shutdownListener;

                    hostOutputMessage = new DataOnlyHostOutputMessage();
                }

                functionExecutor.HostOutputMessage = hostOutputMessage;

                IEnumerable<FunctionDescriptor> descriptors = functions.ReadAllDescriptors();
                int descriptorsCount = descriptors.Count();

                if (descriptorsCount == 0)
                {
                    trace.Warning("No functions found. Try making job classes and methods public.", TraceSource.Indexing);
                }
                else
                {
                    StringBuilder functionsTrace = new StringBuilder();
                    functionsTrace.AppendLine("Found the following functions:");
                    
                    foreach (FunctionDescriptor descriptor in descriptors)
                    {
                        functionsTrace.AppendLine(descriptor.FullName);
                    }

                    trace.Info(functionsTrace.ToString(), TraceSource.Indexing);
                }

                return new JobHostContext(functions, hostCallExecutor, listener, trace);
            }
        }
        public static async Task <JobHostContext> CreateAndLogHostStartedAsync(
            JobHost host,
            IStorageAccountProvider storageAccountProvider,
            IQueueConfiguration queueConfiguration,
            ITypeLocator typeLocator,
            IJobActivator activator,
            INameResolver nameResolver,
            IConsoleProvider consoleProvider,
            JobHostConfiguration config,
            CancellationToken shutdownToken,
            CancellationToken cancellationToken,
            IHostIdProvider hostIdProvider                                 = null,
            FunctionExecutor functionExecutor                              = null,
            IFunctionIndexProvider functionIndexProvider                   = null,
            IBindingProvider bindingProvider                               = null,
            IHostInstanceLoggerProvider hostInstanceLogerProvider          = null,
            IFunctionInstanceLoggerProvider functionInstanceLoggerProvider = null,
            IFunctionOutputLoggerProvider functionOutputLoggerProvider     = null,
            IBackgroundExceptionDispatcher backgroundExceptionDispatcher   = null,
            SingletonManager singletonManager                              = null)
        {
            if (hostIdProvider == null)
            {
                hostIdProvider = new DynamicHostIdProvider(storageAccountProvider, () => functionIndexProvider);
            }

            IExtensionTypeLocator extensionTypeLocator = new ExtensionTypeLocator(typeLocator);

            if (backgroundExceptionDispatcher == null)
            {
                backgroundExceptionDispatcher = BackgroundExceptionDispatcher.Instance;
            }
            ContextAccessor <IMessageEnqueuedWatcher> messageEnqueuedWatcherAccessor = new ContextAccessor <IMessageEnqueuedWatcher>();
            ContextAccessor <IBlobWrittenWatcher>     blobWrittenWatcherAccessor     = new ContextAccessor <IBlobWrittenWatcher>();
            ISharedContextProvider sharedContextProvider = new SharedContextProvider();

            // Create a wrapper TraceWriter that delegates to both the user
            // TraceWriter specified on Config (if present), as well as to Console
            TraceWriter trace = new ConsoleTraceWriter(config.Tracing, consoleProvider.Out);

            // Register system services with the service container
            config.AddService <INameResolver>(nameResolver);

            ExtensionConfigContext context = new ExtensionConfigContext
            {
                Config = config,
                Trace  = trace,
                Host   = host
            };

            InvokeExtensionConfigProviders(context);

            IExtensionRegistry      extensions             = config.GetExtensions();
            ITriggerBindingProvider triggerBindingProvider = DefaultTriggerBindingProvider.Create(nameResolver,
                                                                                                  storageAccountProvider, extensionTypeLocator, hostIdProvider, queueConfiguration, backgroundExceptionDispatcher,
                                                                                                  messageEnqueuedWatcherAccessor, blobWrittenWatcherAccessor, sharedContextProvider, extensions, trace);

            if (bindingProvider == null)
            {
                bindingProvider = DefaultBindingProvider.Create(nameResolver, storageAccountProvider, extensionTypeLocator, messageEnqueuedWatcherAccessor, blobWrittenWatcherAccessor, extensions);
            }

            DefaultLoggerProvider loggerProvider = new DefaultLoggerProvider(storageAccountProvider, trace);

            if (singletonManager == null)
            {
                singletonManager = new SingletonManager(storageAccountProvider, backgroundExceptionDispatcher, config.Singleton, trace, config.NameResolver);
            }

            using (CancellationTokenSource combinedCancellationSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, shutdownToken))
            {
                CancellationToken combinedCancellationToken = combinedCancellationSource.Token;

                await WriteSiteExtensionManifestAsync(combinedCancellationToken);

                IStorageAccount dashboardAccount = await storageAccountProvider.GetDashboardAccountAsync(combinedCancellationToken);

                IHostInstanceLogger hostInstanceLogger = null;
                if (hostInstanceLogerProvider != null)
                {
                    hostInstanceLogger = await hostInstanceLogerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    hostInstanceLogger = await((IHostInstanceLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken);
                }

                IFunctionInstanceLogger functionInstanceLogger = null;
                if (functionInstanceLoggerProvider != null)
                {
                    functionInstanceLogger = await functionInstanceLoggerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    functionInstanceLogger = (IFunctionInstanceLogger)(await((IFunctionInstanceLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken));
                }

                IFunctionOutputLogger functionOutputLogger = null;
                if (functionOutputLoggerProvider != null)
                {
                    functionOutputLogger = await functionOutputLoggerProvider.GetAsync(combinedCancellationToken);
                }
                else
                {
                    functionOutputLogger = (IFunctionOutputLogger)(await((IFunctionOutputLoggerProvider)loggerProvider).GetAsync(combinedCancellationToken));
                }

                if (functionExecutor == null)
                {
                    functionExecutor = new FunctionExecutor(functionInstanceLogger, functionOutputLogger, backgroundExceptionDispatcher, trace, config.FunctionTimeout);
                }

                if (functionIndexProvider == null)
                {
                    functionIndexProvider = new FunctionIndexProvider(typeLocator, triggerBindingProvider, bindingProvider, activator, functionExecutor, extensions, singletonManager);
                }

                IFunctionIndex functions = await functionIndexProvider.GetAsync(combinedCancellationToken);

                IListenerFactory functionsListenerFactory = new HostListenerFactory(functions.ReadAll(), singletonManager, activator, nameResolver, trace);

                IFunctionExecutor hostCallExecutor;
                IListener         listener;
                HostOutputMessage hostOutputMessage;

                if (dashboardAccount != null)
                {
                    string hostId = await hostIdProvider.GetHostIdAsync(cancellationToken);

                    string sharedQueueName = HostQueueNames.GetHostQueueName(hostId);
                    IStorageQueueClient dashboardQueueClient       = dashboardAccount.CreateQueueClient();
                    IStorageQueue       sharedQueue                = dashboardQueueClient.GetQueueReference(sharedQueueName);
                    IListenerFactory    sharedQueueListenerFactory = new HostMessageListenerFactory(sharedQueue,
                                                                                                    queueConfiguration, backgroundExceptionDispatcher, trace, functions,
                                                                                                    functionInstanceLogger, functionExecutor);

                    Guid             hostInstanceId               = Guid.NewGuid();
                    string           instanceQueueName            = HostQueueNames.GetHostQueueName(hostInstanceId.ToString("N"));
                    IStorageQueue    instanceQueue                = dashboardQueueClient.GetQueueReference(instanceQueueName);
                    IListenerFactory instanceQueueListenerFactory = new HostMessageListenerFactory(instanceQueue,
                                                                                                   queueConfiguration, backgroundExceptionDispatcher, trace, functions,
                                                                                                   functionInstanceLogger, functionExecutor);

                    HeartbeatDescriptor heartbeatDescriptor = new HeartbeatDescriptor
                    {
                        SharedContainerName = HostContainerNames.Hosts,
                        SharedDirectoryName = HostDirectoryNames.Heartbeats + "/" + hostId,
                        InstanceBlobName    = hostInstanceId.ToString("N"),
                        ExpirationInSeconds = (int)HeartbeatIntervals.ExpirationInterval.TotalSeconds
                    };

                    IStorageBlockBlob blob = dashboardAccount.CreateBlobClient()
                                             .GetContainerReference(heartbeatDescriptor.SharedContainerName)
                                             .GetBlockBlobReference(heartbeatDescriptor.SharedDirectoryName + "/" + heartbeatDescriptor.InstanceBlobName);
                    IRecurrentCommand heartbeatCommand = new UpdateHostHeartbeatCommand(new HeartbeatCommand(blob));

                    IEnumerable <MethodInfo> indexedMethods = functions.ReadAllMethods();
                    Assembly hostAssembly = GetHostAssembly(indexedMethods);
                    string   displayName  = hostAssembly != null?hostAssembly.GetName().Name : "Unknown";

                    hostOutputMessage = new DataOnlyHostOutputMessage
                    {
                        HostInstanceId      = hostInstanceId,
                        HostDisplayName     = displayName,
                        SharedQueueName     = sharedQueueName,
                        InstanceQueueName   = instanceQueueName,
                        Heartbeat           = heartbeatDescriptor,
                        WebJobRunIdentifier = WebJobRunIdentifier.Current
                    };

                    hostCallExecutor = CreateHostCallExecutor(instanceQueueListenerFactory, heartbeatCommand,
                                                              backgroundExceptionDispatcher, shutdownToken, functionExecutor);
                    IListenerFactory hostListenerFactory = new CompositeListenerFactory(functionsListenerFactory,
                                                                                        sharedQueueListenerFactory, instanceQueueListenerFactory);
                    listener = CreateHostListener(hostListenerFactory, heartbeatCommand, backgroundExceptionDispatcher, shutdownToken);

                    // Publish this to Azure logging account so that a web dashboard can see it.
                    await LogHostStartedAsync(functions, hostOutputMessage, hostInstanceLogger, combinedCancellationToken);
                }
                else
                {
                    hostCallExecutor = new ShutdownFunctionExecutor(shutdownToken, functionExecutor);

                    IListener factoryListener  = new ListenerFactoryListener(functionsListenerFactory);
                    IListener shutdownListener = new ShutdownListener(shutdownToken, factoryListener);
                    listener = shutdownListener;

                    hostOutputMessage = new DataOnlyHostOutputMessage();
                }

                functionExecutor.HostOutputMessage = hostOutputMessage;

                IEnumerable <FunctionDescriptor> descriptors = functions.ReadAllDescriptors();
                int descriptorsCount = descriptors.Count();

                if (descriptorsCount == 0)
                {
                    trace.Warning(string.Format("No job functions found. Try making your job classes and methods public. {0}",
                                                Constants.ExtensionInitializationMessage), TraceSource.Indexing);
                }
                else
                {
                    StringBuilder functionsTrace = new StringBuilder();
                    functionsTrace.AppendLine("Found the following functions:");

                    foreach (FunctionDescriptor descriptor in descriptors)
                    {
                        functionsTrace.AppendLine(descriptor.FullName);
                    }

                    trace.Info(functionsTrace.ToString(), TraceSource.Indexing);
                }

                return(new JobHostContext(functions, hostCallExecutor, listener, trace));
            }
        }
        // Static initialization. Returns a service provider with some new services initialized.
        // The new services:
        // - can retrieve static config like binders and converters; but the listeners haven't yet started.
        // - can be flowed into the runtime initialization to get a JobHost spun up and running.
        // This is just static initialization and should not need to make any network calls,
        // and so this method should not need to be async.
        // This can be called multiple times on a config, which is why it returns a new ServiceProviderWrapper
        // instead of modifying the config.
        public static ServiceProviderWrapper CreateStaticServices(this JobHostConfiguration config)
        {
            var services = new ServiceProviderWrapper(config);

            var consoleProvider = services.GetService <IConsoleProvider>();
            var nameResolver    = services.GetService <INameResolver>();
            IWebJobsExceptionHandler exceptionHandler   = services.GetService <IWebJobsExceptionHandler>();
            IQueueConfiguration      queueConfiguration = services.GetService <IQueueConfiguration>();
            var blobsConfiguration = config.Blobs;

            IStorageAccountProvider storageAccountProvider = services.GetService <IStorageAccountProvider>();
            IBindingProvider        bindingProvider        = services.GetService <IBindingProvider>();
            SingletonManager        singletonManager       = services.GetService <SingletonManager>();

            IHostIdProvider hostIdProvider = services.GetService <IHostIdProvider>();
            var             hostId         = config.HostId;

            if (hostId != null)
            {
                hostIdProvider = new FixedHostIdProvider(hostId);
            }

            // Need a deferred getter since the IFunctionIndexProvider service isn't created until later.
            Func <IFunctionIndexProvider> deferredGetter = () => services.GetService <IFunctionIndexProvider>();

            if (hostIdProvider == null)
            {
                hostIdProvider = new DynamicHostIdProvider(storageAccountProvider, deferredGetter);
            }
            services.AddService <IHostIdProvider>(hostIdProvider);

            AzureStorageDeploymentValidator.Validate();

            IExtensionTypeLocator extensionTypeLocator = services.GetService <IExtensionTypeLocator>();

            if (extensionTypeLocator == null)
            {
                extensionTypeLocator = new ExtensionTypeLocator(services.GetService <ITypeLocator>());
                services.AddService <IExtensionTypeLocator>(extensionTypeLocator);
            }

            ContextAccessor <IMessageEnqueuedWatcher> messageEnqueuedWatcherAccessor = new ContextAccessor <IMessageEnqueuedWatcher>();

            services.AddService(messageEnqueuedWatcherAccessor);
            ContextAccessor <IBlobWrittenWatcher> blobWrittenWatcherAccessor = new ContextAccessor <IBlobWrittenWatcher>();
            ISharedContextProvider sharedContextProvider = new SharedContextProvider();

            // Create a wrapper TraceWriter that delegates to both the user
            // TraceWriters specified via config (if present), as well as to Console
            TraceWriter trace = new ConsoleTraceWriter(config.Tracing, consoleProvider.Out);

            services.AddService <TraceWriter>(trace);

            // Add built-in extensions
            var metadataProvider = new JobHostMetadataProvider(deferredGetter);

            metadataProvider.AddAttributesFromAssembly(typeof(TableAttribute).Assembly);

            var  exts          = config.GetExtensions();
            bool builtinsAdded = exts.GetExtensions <IExtensionConfigProvider>().OfType <TableExtension>().Any();

            if (!builtinsAdded)
            {
                config.AddExtension(new TableExtension());
                config.AddExtension(new QueueExtension());
            }

            ExtensionConfigContext context = new ExtensionConfigContext
            {
                Config          = config,
                Trace           = trace,
                PerHostServices = services
            };

            InvokeExtensionConfigProviders(context);

            // After this point, all user configuration has been set.

            if (singletonManager == null)
            {
                var logger = config.LoggerFactory?.CreateLogger(LogCategories.Singleton);

                IDistributedLockManager lockManager = services.GetService <IDistributedLockManager>();
                if (lockManager == null)
                {
                    lockManager = new BlobLeaseDistributedLockManager(
                        storageAccountProvider,
                        trace,
                        logger);
                    services.AddService <IDistributedLockManager>(lockManager);
                }

                singletonManager = new SingletonManager(
                    lockManager,
                    config.Singleton,
                    trace,
                    exceptionHandler,
                    config.LoggerFactory,
                    hostIdProvider,
                    services.GetService <INameResolver>());
                services.AddService <SingletonManager>(singletonManager);
            }

            IExtensionRegistry      extensions             = services.GetExtensions();
            ITriggerBindingProvider triggerBindingProvider = DefaultTriggerBindingProvider.Create(nameResolver,
                                                                                                  storageAccountProvider, extensionTypeLocator, hostIdProvider, queueConfiguration, blobsConfiguration, exceptionHandler,
                                                                                                  messageEnqueuedWatcherAccessor, blobWrittenWatcherAccessor, sharedContextProvider, extensions, singletonManager, trace, config.LoggerFactory);

            services.AddService <ITriggerBindingProvider>(triggerBindingProvider);

            if (bindingProvider == null)
            {
                bindingProvider = DefaultBindingProvider.Create(nameResolver, config.LoggerFactory, storageAccountProvider, extensionTypeLocator, blobWrittenWatcherAccessor, extensions);
                services.AddService <IBindingProvider>(bindingProvider);
            }

            var converterManager = (ConverterManager)config.ConverterManager;

            metadataProvider.Initialize(bindingProvider, converterManager, exts);
            services.AddService <IJobHostMetadataProvider>(metadataProvider);

            return(services);
        }