Rapid Dapr

Rapid Pub/Sub Approach to aid in getting started with Dapr, .NET and Bicep.

The idea

In a previous repo, A Pub/Sub model was introduced but having in mind the goal of bringing about a great development experience. An integrated development experience was not always the case in the plethora of Dapr examples that inhabit the internet.

However, In this repo I take a step further into actualizing, bringing the actual solution to market, or in other words live. A great inspiration to this idea was awesome-azd. While the templates in this portal are compelling, There was an envisioned use case that was not to be found there. This use case involved the following ingredients: Azure Service Bus - Multiple Topics, Multiple Subscriptions, .NET Shared Class Libraries - with a common library for avoiding magical strings on topics.

This boilerplate uses the concept of bicep templates and the azd cli toolkit to bring to production a working solution. The bicep templates are used to create the infrastructure and the azd cli toolkit is used to deploy the application.

Enhance

Introduce or remove additional topics in the servicebus.bicep file. For instances under the serviceBusNamespace resource, topics could be define as follows:

param activityTopic string = 'activity'
param subName string = 'sub'

resource serviceBusNamespace 'Microsoft.ServiceBus/namespaces@2021-06-01-preview' = {
  name: serviceBusNamespaceName
  location: location
  .....

  resource topic 'topics' = {
    name: activityTopic
    properties: {
      supportOrdering: true
    }

    resource subscription 'subscriptions' = {
      name: subName
      properties: {
        deadLetteringOnFilterEvaluationExceptions: true
        deadLetteringOnMessageExpiration: true
        maxDeliveryCount: 10
      }
    }
  }
}

Finally, ehance the Subscriber and Publisher controllers to produce and emit the desired event based on the subscriptions.

Publisher

        [HttpPost(DaprTopics.Activity)]
        public async Task<IActionResult> PostMessage([FromBody] ActivityMessageDTO message)
        {
            Console.WriteLine($"Calling Publish Action:- {message.Key}, DateTime: - {DateTime.Now}");
            await activityHelper.PublishToTopic(DaprTopics.Activity, message);
            return Ok();
        }

Subscriber

        [Topic(DaprActivityConfig.PUBSUB, DaprTopics.Activity)]
        [HttpPost(DaprTopics.Test)]
        public IActionResult Post([FromBody] ActivityMessageDTO message)
        {
            Console.WriteLine($"Published topic:{DaprTopics.Test} Action:- {message.Key}, DateTime: - {DateTime.Now}");
            return Ok();
        }

Deploy

Thanks to the azd cli toolkit, the deployment of the application is as simple as running the following command:

azd login
azd up