dotnet-rabbitmq-client-instrumentation-app-insights

A RabbitMQ client for ASP .NET Core 6 with instrumentation so that events are properly correlated in Application Insights.

How to use

Explore the InstrumentedRabbitMqDotNetClient.TestApplication to understand how to use it. It showcases this sequence:

PublishEventController => Publishes TestEvent => TestSubscription receives it and publishes TestEvent2 => Test2Subscription receives it.

Register it in Startup

In the Startup class, add:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // Other initialization logc
        services.AddRabbitMQSubscriberHostedService("name-of-the-queue");
    }
}

Create an event

Declare a record that inherits from IEvent.

public record MyEvent : IEvent
{
    public string EventName => "my.event";
}

Publish an event

Inject IEventPublisher in a class:

public class MyClass
{
    private readonly IEventPublisher _eventPublisher;

    public MyClass(IEventPublisher eventPublisher)
    {
        _eventPublisher = eventPublisher;
    }

    public void DoSomething()
    {
        this._eventPublisher.Publish(new MyEvent())
    }
}

Subscribe to an event

Create a class to inherit from IEventSubscription<MyEvent>:

public class MyEventSubscription : IEventSubscription<MyEvent>
{
    public Task HandleEventAsync(MyEvent receivedEvent, string operationId)
    {
        // Your logic here.
    }
}

Instrumentation

The aporoach is to emualte Azure Service Bus, so that Application Insights shows the nested messages and adds some information about the queue as shown in the image above.

But you do not have to do anything besides configure the Application Insights connection string.

More info

How it works

A DiagnosticSource is available in the Instrumentation folder (It is a simplification of the ServiceBusDiagnosticSource).

The EventPublisher uses it to start the activity.

The RabbitMQSubscriberHostedService uses it to start processing the event and to to signal that the event processing has finished.

Set connection string

Create an Azure Application Insights.
Copy the connection string.
Set it in the env var APPLICATIONINSIGHTS_CONNECTION_STRING. When debugging, it is in the launchSettings.json file in th Properties folder of the TestApplication.

JoanComasFdz/dotnet-rabbitmq-client-instrumentation-app-insights