MqttHostedServer.IsStarted property is always false in asp.net

[tulio84z]

Im following the Server_ASP_NET_Samples to have my mqttbroker working in asp.net. However, in my MqttController, when i inject the MqttHostedServer, it always shows IsStarted false. I want it to be true to enable me to use InjectApplicationMessage to inject application messages depending on certain situations. I have no idea how to set up my application to have the MqttHostedServer show as started. Everything works except injection application messages due to IsStarted being false. What am I missing?

    public static WebApplication ConfigureApplication(this WebApplicationBuilder builder)
    {
        // Configure AppSettings
        var appSettings = builder.ConfigureAppSettings();

        builder.WebHost.ConfigureKestrel(options =>
        {

            options.ListenAnyIP(appSettings.MqttClient.Ports.Mqtt, listenOptions => listenOptions.UseMqtt());
            options.ListenAnyIP(appSettings.MqttClient.Ports.Ws);

        });

        builder.Services.AddHostedMqttServer(optionsBuilder =>
        {
            optionsBuilder.WithDefaultEndpoint();
        });

        builder.Services.AddMqttConnectionHandler()
            .AddConnections();

        builder.Services.AddSingleton<MqttController>();

        var mqttController = builder.Services.BuildServiceProvider().GetRequiredService<MqttController>();

        var app = builder.Build();
        app.UseRouting()
            .UseEndpoints(
                endpoints =>
                {
                    endpoints.MapConnectionHandler<MqttConnectionHandler>(
                        "/mqtt",
                        httpConnectionDispatcherOptions => httpConnectionDispatcherOptions.WebSockets.SubProtocolSelector =
                            protocolList => protocolList.FirstOrDefault() ?? string.Empty);
                });
        app.UseMqttServer(server =>
        {
            server.ValidatingConnectionAsync += mqttController.ValidateConnection;
            server.ClientConnectedAsync += mqttController.OnClientConnected;
            server.ClientSubscribedTopicAsync += mqttController.ServerOnClientSubscribedTopicAsync;
            server.InterceptingPublishAsync += mqttController.ServerOnInterceptingPublishAsync;
            });
        return app;
    }

This is my MqttController:

public class MqttController
{
    private readonly ILogger _logger;
    private readonly IServiceProvider _serviceProvider;
    private readonly MqttServer _mqttServer;

    public MqttController(ILogger<MqttController> logger, IServiceProvider serviceProvider, MqttHostedServer mqttServer)
    {
        _logger = logger;
        _serviceProvider = serviceProvider;
        _mqttServer = mqttServer;
    }

    public async Task<Task> OnClientConnected(ClientConnectedEventArgs eventArgs)
    {
        // Create a new message using the builder as usual.
        var message = new MqttApplicationMessageBuilder().WithTopic("HelloWorld").WithPayload("Test").Build();

        // This throws exception as _mqttServer is not started
        await _mqttServer.InjectApplicationMessage(
            new InjectedMqttApplicationMessage(message)
            {
                SenderClientId = "SenderClientId"
            });
        _logger.LogInformation($"Client '{eventArgs.ClientId}' connected.");
        return CompletedTask.Instance;
    }
}

[tulio84z]

Ok i got IsStarted to be true to work by instantiating MqttHostedServer myself and doing a StartAsync as such:

    public static WebApplication ConfigureApplication(this WebApplicationBuilder builder)
    {
        // Configure AppSettings
        var appSettings = builder.ConfigureAppSettings();
        builder.WebHost.ConfigureKestrel(options =>
        {
            options.ListenAnyIP(appSettings.MqttClient.Ports.Mqtt, listenOptions => listenOptions.UseMqtt());
            options.ListenAnyIP(appSettings.MqttClient.Ports.Ws);
        });

        /*builder.Services.AddHostedMqttServer(optionsBuilder =>
        {
            optionsBuilder.WithDefaultEndpoint();
        });*/

        builder.Services.AddMqttConnectionHandler()
            .AddConnections();

        builder.Services.AddSingleton(_ =>
        {
            var mqttServerOptions = new MqttServerOptionsBuilder()
                .WithDefaultEndpoint()
                .Build();
            return mqttServerOptions;
        });
        builder.Services.AddSingleton<IMqttNetLogger>(MqttNetNullLogger.Instance);
        builder.Services.AddSingleton<MqttFactory>();

        builder.Services.AddSingleton<MqttController>();
        builder.Services.AddSingleton(s =>
        {
            var mqttFactory = s.GetService<MqttFactory>();

            var mqttServerOptions = s.GetService<MqttServerOptions>();
            var mqttServerAdapter = s.GetService<IMqttServerAdapter>();
            var mqttNetLogger = s.GetService<IMqttNetLogger>();

            var mqttServer = new MqttHostedServer(mqttFactory, mqttServerOptions, new[] { mqttServerAdapter }, mqttNetLogger);
            
            mqttServer.StartAsync();
            return mqttServer;
        });
        
        builder.Services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
        builder.Services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
        
        var mqttController = builder.Services.BuildServiceProvider().GetRequiredService<MqttController>();

        var app = builder.Build();
        app.UseRouting()
            .UseEndpoints(
                endpoints =>
                {
                    endpoints.MapConnectionHandler<MqttConnectionHandler>(
                        "/mqtt",
                        httpConnectionDispatcherOptions => httpConnectionDispatcherOptions.WebSockets.SubProtocolSelector =
                            protocolList => protocolList.FirstOrDefault() ?? string.Empty);
                });
        app.UseMqttServer(server =>
        {
            server.ValidatingConnectionAsync += mqttController.ValidateConnection;
            server.ClientConnectedAsync += mqttController.OnClientConnected;
            server.ClientSubscribedTopicAsync += mqttController.ServerOnClientSubscribedTopicAsync;
            server.InterceptingPublishAsync += mqttController.ServerOnInterceptingPublishAsync;
            });
        return app;
    }

However, InjectApplicationMessage does not work at all for some reason. These are the relevant parts in my MqttController:

public class MqttController
{
    private readonly ILogger _logger;
    private readonly IServiceProvider _serviceProvider;
    private readonly MqttServer _mqttServer;
    public MqttController(ILogger<MqttController> logger, IServiceProvider serviceProvider, MqttServer mqttServer)
    {
        _logger = logger;
        _serviceProvider = serviceProvider;
        _mqttServer = mqttServer;
    }
    public async Task<Task> OnClientConnected(ClientConnectedEventArgs eventArgs)
    {
        // Create a new message using the builder as usual.
        var message = new MqttApplicationMessageBuilder().WithTopic("HelloWorld").WithPayload("Test").Build();

        // Now inject the new message at the broker.
        await _mqttServer.InjectApplicationMessage(
            new InjectedMqttApplicationMessage(message)
            {
                SenderClientId = "SenderClientId"
            });
        _logger.LogInformation($"Client '{eventArgs.ClientId}' connected.");
        return CompletedTask.Instance;
    }
}

Everything works except InjectApplicationMessage for some reason.