How-To: Add a Dapr building block

Learn how to add a Dapr building block to a Radius Application
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This how-to guide will provide an overview of how to:

Prerequisites

Step 1: Start with a container and a Dapr sidecar

Begin by creating a file named app.bicep with a defined Radius container and a Dapr sidecar, if you need a in-depth walkthrough see the ‘How-To: Add a Dapr sidecar to a container’ guide:

import radius as radius

@description('The ID of your Radius Application. Automatically injected by the rad CLI.')
param application string

@description('The ID of your Radius environment. Automatically injected by the rad CLI.')
param environment string

resource demo 'Applications.Core/containers@2023-10-01-preview' = {
  name: 'demo'
  properties: {
    application: application
    container: {
      image: 'ghcr.io/radius-project/samples/demo:latest'
      ports: {
        web: {
          containerPort: 3000
        }
      }
    }
    extensions: [
      {
        kind: 'daprSidecar'
        appId: 'demo'
        appPort: 3000
      }
    ]
  }
}

Step 2: Add a Dapr state store resource

Now add a Dapr state store resource, which models a Dapr state store component. The underlying infrastructure and Dapr component configuration are deployed via a local-dev Recipe, which leverages a lightweight Redis container:

resource stateStore 'Applications.Dapr/stateStores@2023-10-01-preview' = {
  name: 'statestore'
  properties: {
    environment: environment
    application: application
  }
}

Visit the Radius Recipe repo to learn more about local-dev Recipes and view the Dapr State Store Recipe used in this guide.

Step 3: Add a connection from the container resource to the Dapr state store resource

Update your container resource with a connection to the Dapr state store. This will inject important connection information (the component name) into the container’s environment variables:

resource demo 'Applications.Core/containers@2023-10-01-preview' = {
  name: 'demo'
  properties: {
    application: application
    container: {
      image: 'ghcr.io/radius-project/samples/demo:latest'
      ports: {
        web: {
          containerPort: 3000
        }
      }
    }
    extensions: [
      {
        kind: 'daprSidecar'
        appId: 'demo'
        appPort: 3000
      }
    ]
    connections: {
      redis: {
        source: stateStore.id
      }
    }
  }
}

Step 3: Deploy the application

Run your application with the rad CLI:

rad run ./app.bicep -a demo

Your console output should look similar to:

Building ./app.bicep...
Deploying template './app.bicep' for application 'demo' and environment 'default' from workspace 'default'...

Deployment In Progress... 

Completed            statestore      Applications.Dapr/stateStores
...                  demo            Applications.Core/containers

Deployment Complete

Resources:
    demo            Applications.Core/containers
    statestore      Applications.Dapr/stateStores

Starting log stream...

Open http://localhost:3000 to view the Radius demo container. Which should contain the following connection information:

Step 4: Verify the Dapr statestore

Run the command below to see all the pods running in your Kubernetes cluster:

dapr components --namespace "default-demo" -k

The console output should similar to:

NAMESPACE     NAME        TYPE         VERSION  SCOPES  CREATED              AGE  
default-demo  statestore  state.redis  v1               2024-02-19 17:13.20  2m

Done

You’ve successfully deployed a Radius container with a Dapr sidecar along with a Dapr State Store. With the combination of Radius + Dapr, both your application’s code and it’s definition are now platform neutral.

Cleanup

To delete your app, run the rad app delete command to cleanup the app and its resources, including the Recipe resources:

rad app delete -a demo

Further reading