Call service.AddKakfa() multiple times

[ravi-kotha]

Hi All,

Is there a way we can invoke service.AddKafka() multiple times with the same app?
I am trying to build abstractions for various producer contexts and in some cases I will have to use more then one of these abstractions in a single application.

I tried to call this multiple times and looks like it does not resolve the instances properly after that, anyway I can achieve this?

[filipeesch]

Hi @ravi-kotha,

You can call AddKafka multiple times if your application has more than one ServiceCollection/ServiceProvider, but is not usual.

Maybe you can achieve that by calling AddKafka just one time and call the AddProducer multiple times, like:

services.AddKafkaFlowHostedService(kafka => kafka
    .AddCluster(cluster => cluster
    {
        foreach(var producerCOnfig in producersConfig)
            cluster.AddProducer(...)
    })
);

[ravi-kotha]

I am already adding multiple producers, but these will live in separate nugets, So I have a Web App which will consume these different packages for producing different stuff to different topics and I wanted to abstract all the DI into the nugets, but I realized if I did that in the nugets then I cannot add both the nugets in the web app at the same time since they both call the AddKafka piece separately. Both these nugets have extension methods which will use the consuming apps ServiceCollection object.

[filipeesch]

Wouldn't be better to create extension methods on IClusterConfigurationBuilder in your packages with the producer configurations? And use like this:

services.AddKafkaFlowHostedService(kafka => kafka
    .AddCluster(cluster => cluster
    {
            cluster.AddProducerOne(...) // your extension method
            cluster.AddProducerTwo(...) // your extension method
    })
);

[ravi-kotha]

That could work, let me try. Thanks.

[ravi-kotha]

You are the man 👏👏, that works. Thank you so much for the quick replies.