Cannot See Published Messages on RabbitMQ Dashboard After Publish Event - docker

Question

I run RabbitMQ through Docker Desktop with the following settings:
rabbitmq:
container_name: rabbitmq
restart: always
ports:
- "5672:5672"
- "15672:15672"
Second port number is for the RabbitMQ Dashboard. And, I have a basic REST API endpoint which is supposed to publish a RabbitMQ message as follows:
private readonly IMediator _mediator;
private readonly IPublishEndpoint _publish;
public FlightController(IMediator mediator, IPublishEndpoint publish)
{
_mediator = mediator;
_publish = publish;
}
[HttpPost(Name = "CheckoutCrew")]
[ProducesResponseType((int)HttpStatusCode.Accepted)]
public async Task<IActionResult> CheckoutCrew([FromBody] ScheduleFlightCommand command)
{
var crewIds = new List<string>() { command.SeniorCrewId, command.Crew1Id, command.Crew2Id, command.Crew3Id };
var hasSchedule = true;
var crewCheckoutEvent = new CrewCheckoutEvent() { EmployeeNumbers = crewIds, HasSchedule = hasSchedule };
await _publish.Publish(crewCheckoutEvent);
return Accepted();
}
And, below codes represent the configurations regarding RabbitMQ:
services.AddMassTransit(config => {
config.UsingRabbitMq((ctx, cfg) => {
cfg.Host(Configuration["EventBusSettings:HostAddress"]);
cfg.UseHealthCheck(ctx);
});
});
services.AddMassTransitHostedService();
This Configuration["EventBusSettings:HostAddress"] line points here on appsettings.json:
"EventBusSettings": {
"HostAddress": "amqp://guest:guest#localhost:5672"
}
After I have run my API (named Flight.API), I check RabbitMQ logs via DockerDesktop and see these:
2022-03-31 12:52:41.794701+00:00 [info] <0.1020.0> accepting AMQP connection <0.1020.0> (xxx.xx.x.x:45292 -> xxx.xx.x.x:5672)
2022-03-31 12:52:41.817563+00:00 [info] <0.1020.0> Connection <0.1020.0> (xxx.xx.x.x:45292 -> xxx.xx.x.x:5672) has a client-provided name: Flight.API
2022-03-31 12:52:41.820704+00:00 [info] <0.1020.0> connection <0.1020.0> (xxx.xx.x.x:45292 -> xxx.xx.x.x:5672 - Flight.API): user 'guest' authenticated and granted access to vhost '/'
Everything seems okay, do not they?
I have also wrap .Publish method with try...catch but it also doesn't throw any exceptions. When my endpoint returns Accepted without any issue, I go and check RabbitMQ dashboard but it shows Connections: 0, Channels: 0 etc. Message rates section is also staying on idle.
I cannot see what I am missing.
(Currently, I do not have any consumers, but I should still see some life signs, am I right? Those Connections and Channels counters shouldn't be staying at 0 after I have successfully published my payload)
Thank you in advance.
Edit after adding a consumer class
Still no changes on RabbitMQ Management screens. Everything is on their default values, empty, or idle. Below is my configuration on the consumer project:
services.AddMassTransit(config => {
config.AddConsumer<CrewChecoutConsumer>();
config.UsingRabbitMq((ctx, cfg) => {
cfg.Host(Configuration["EventBusSettings:HostAddress"]);
cfg.UseHealthCheck(ctx);
cfg.ReceiveEndpoint(EventBusConstants.CrewCheckoutQueue, config => {
config.ConfigureConsumer<CrewChecoutConsumer>(ctx);
});
});
});
services.AddMassTransitHostedService();
services.AddScoped<CrewChecoutConsumer>();
appsettings.json file on consumer project is changed accordingly:
"EventBusSettings": {
"HostAddress": "amqp://guest:guest#localhost:5672"
}
And, below is my complete consumer class:
public class CrewChecoutConsumer : IConsumer<CrewCheckoutEvent>
{
private readonly IMapper _mapper;
private readonly IMediator _mediator;
public CrewChecoutConsumer(IMapper mapper, IMediator mediator)
{
_mapper = mapper;
_mediator = mediator;
}
public async Task Consume(ConsumeContext<CrewCheckoutEvent> context)
{
foreach (var employeeNumber in context.Message.EmployeeNumbers)
{
var query = new GetSingleCrewQuery(employeeNumber);
var crew = await _mediator.Send(query);
crew.HasSchedule = context.Message.HasSchedule;
var updateCrewCommand = new UpdateCrewCommand();
_mapper.Map(crew, updateCrewCommand, typeof(CrewModel), typeof(UpdateCrewCommand));
var result = await _mediator.Send(updateCrewCommand);
}
}
}

Answer 1

If you do not have any consumers, the only thing you will see is a message rate on the published message exchange as messages are delivered to the exchange, but then discarded as there are no receive endpoints (queues) bound to that message type exchange.
Until you have a consumer, you won't see any messages in any queues.
Also, you should pass the controller's CancellationToken to the Publish call.