DAPR: publish and subscribe messages example

Example: Distributed Application Runtime(DAPR) Publish and Subscriber messages

• Using .NET7
• Using RabbitMQ on local
• Using Container App, Dapr Component and AzureServiceBus in Azure
• CI/CD: GitHub Action

Requirements

---

• Install Dapr
• Install .NET7

Structures

---

• Producer: using the API sends messages
• Consumer: receive messages from pubSubName and Topic
• Messages: create message model
• ComponentsLocal: pubsub.yaml is config your message bus (RabbitMQ)
• Components: pubsub.yaml is config your message bus (Azure Service Bus)

Usages

• Start RabbitMQ:

  cd DemoMicroservices
  docker-compose up
  

• Using RabbitMQ: Set PubSubName="order-pub-sub"

• Start Consumer(app-id: checkout)

  cd DemoMicroservices\Consumer
  dapr run --app-id checkout --components-path ../../ComponentsLocal --app-port 5000 --dapr-http-port 3500 --dapr-grpc-port 60002 dotnet run
  

  The /checkout endpoint matches the route defined in the subscriptions and this is where Dapr will send all topic messages to. It will be created a queue with name: checkout-orders

• Start Producer(app-id: orderprocessing)

  cd DemoMicroservices\Producer
  dapr run --app-id orderprocessing --app-port 5011 --dapr-http-port 3501 --dapr-grpc-port 60001 --components-path ../../ComponentsLocal dotnet run
  

• Send a message from Producer to Consumer

  http://localhost:5011/order
  {
      "OrderAmount":12.7,
      "OrderNumber":"Num18291",
      "OrderDate":"2021-12-21"
  }
  

Using Azure Container App and Azure Service Bus

• Create Azure Credential

  az ad sp create-for-rbac --name "myApp" --role contributor \
      --scopes /subscriptions/{subscription-id}/resourceGroups/{resource-group} \
      --sdk-auth
  

• Create Dapr Component

  • $ENVIRONMENT: Container App Environment

  az containerapp env dapr-component set \
      --name $ENVIRONMENT --resource-group $RESOURCE_GROUP \
      --dapr-component-name order-pub-sub \
      --yaml '.\Components\pubsub.yaml'
  

• Enable Ingress in Producer Container

  az containerapp ingress enable --name producer-container  \
      --resource-group containers --target-port 80 --exposed-port 80 \
      --transport http --type external --allow-insecure
  

Result

• Publish message

• Consumer message

• Consumer Container Config in Azure

• Producer Container Config in Azure

• Add Dapr Component in Azure

• Producer Logging in Azure

• Consumer Container Logging in Azure

References

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• Dapr Pub Sub ASP Net Core integration
• Dapr publish subcriber for net developers
• Publish a message and subscribe to a topic