ASP.net Core MVC + REST server

Describe your question

I’m trying to do a server REST and MQTT with ASP.net Core MVC for working with Unity3D. The REST server is working fine. I’m facing that issue when trying to connect to the server with WebSocket: QTTnet.Exceptions.MqttCommunicationException: Unable to connect to the remote server —> System.Net.WebSockets.WebSocketException: Unable to connect to the remote server

I tried for one week to make it work but I’m running out of ideas. I would be grateful if you guys can tell me what did I missed.

Versions: Microsoft.AspDotNetCore.App 3.1.2 Microsoft.NETCore.App 3.1.0 Microsoft.AspNetCore.Mvc.NewtonsoftJson 3.1.3 MQTTnet 3.0.11 MQTTnet.AspNetCore 3.0.11

The client connection part:

            var id = SystemInfo.deviceUniqueIdentifier;
            var factory = new MqttFactory();
            this.mqttClient = factory.CreateMqttClient();
            
            // WebSocket 
            var options = new MqttClientOptionsBuilder()
                    .WithClientId(id)
                    .WithWebSocketServer("ws://127.0.0.1:5000/mqtt")
                    .WithKeepAlivePeriod(TimeSpan.FromHours(24))
                    .WithKeepAliveSendInterval(TimeSpan.FromSeconds(5))
                    .WithCleanSession()
                    .Build();

            mqttClient.UseDisconnectedHandler(async e => {
                Debug.Log("### DISCONNECTED FROM SERVER ###");
                await Task.Delay(TimeSpan.FromSeconds(5));

                try {
                    await mqttClient.ConnectAsync(options, CancellationToken.None); // Since 3.0.5 with CancellationToken
                } catch (Exception ex) {
                    Debug.Log("### RECONNECTING FAILED ###");
                    Debug.Log(ex);
                }
            });

            try {
                await mqttClient.ConnectAsync(options, CancellationToken.None); // Since 3.0.5 with CancellationToken
            } catch (Exception e) {
                Debug.Log(e);
            }

The server Programm class:

public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
            //CreateHostBuilder(args).Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder => {
            webBuilder.UseStartup<Startup>();
        });

The server Configure Service:

public void ConfigureServices(IServiceCollection services)
        {
            // requires using Microsoft.Extensions.Options
            services.Configure<DatabaseSettings>(
                Configuration.GetSection(nameof(DatabaseSettings)));

            services.AddSingleton<IDatabaseSettings>(sp =>
                sp.GetRequiredService<IOptions<DatabaseSettings>>().Value);

            // Add Services
            services.AddSingleton<Service>();

            // Add Controllers
            services.AddControllers().AddNewtonsoftJson(options => options.UseMemberCasing());

            // MQTT
            services.AddSingleton<MqttService>();
            services.AddHostedMqttServerWithServices(options => {
                var s = options.ServiceProvider.GetRequiredService<MqttService>();
                s.ConfigureMqttServerOptions(options);
            });
            services.AddMqttWebSocketServerAdapter();
            services.AddMqttConnectionHandler();
        }

The server Configure

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment()) {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints => {
                endpoints.MapControllers();
            });

            // MQTT
            _ = app.UseMqttEndpoint();
            app.UseMqttServer(server => app.ApplicationServices.GetRequiredService<MqttService>().ConfigureMqttServer(server));
        }

The server MQTT service witout all the implemented interfaces

public class MqttService : IMqttServerClientConnectedHandler, IMqttServerClientDisconnectedHandler, IMqttServerApplicationMessageInterceptor, IMqttServerConnectionValidator, IMqttServerStartedHandler
    {
        IMqttServer mqtt;

        public void ConfigureMqttServerOptions(AspNetMqttServerOptionsBuilder options)
        {
            options.WithConnectionValidator(this);
            options.WithApplicationMessageInterceptor(this);
        }

        public void ConfigureMqttServer(IMqttServer mqtt)
        {
            this.mqtt = mqtt;
            mqtt.ClientConnectedHandler = this;
            mqtt.ClientDisconnectedHandler = this;
        }

Thanks in advance !

edit: changed the versions to 3.0.11

[VallatMa]

Thanks for all your answers 😃 Because of some time pressure, I made it work by changing from WebSocket to TCP.

So here my working setup:

Startup.cs ConfigureServices

            services.AddSingleton<MqttService>();
            services.AddHostedMqttServerWithServices(options => {
                var s = options.ServiceProvider.GetRequiredService<MqttService>();
                s.ConfigureMqttServerOptions(options);
            });
            services.AddConnections();
            services.AddMqttConnectionHandler();

Startup.cs Configure

            app.UseHttpsRedirection();
            app.UseRouting();
            app.UseAuthorization();
            app.UseEndpoints(endpoints => {
                endpoints.MapControllers();
                endpoints.MapMqtt("/mqtt");
            });
            app.UseMqttServer(server => app.ApplicationServices.GetRequiredService<MqttService>().ConfigureMqttServer(server));

Program.cs

public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder => {
            webBuilder.ConfigureKestrel(serverOptions => {
                serverOptions.ListenAnyIP(1883, l => l.UseMqtt()); 
                serverOptions.ListenAnyIP(5000, l => l.UseHttps()); 
            }).UseStartup<Startup>();
        });

[SeppPenner]

@JimmyPun610’s solution should work, as far as I can see from the examples 😃