How-To: Use a Kubernetes resources in your application

Learn how to use a Kubernetes resources in your application
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This how-to guide will provide an overview of how to:

  • Leverage Kubernetes resources in your Radius Application directly.

Prerequisites

Step 1: Define the Kubernetes provider

Begin by creating a new file named app.bicep. At the top of your file, import the kubernetes provider and add its configuration. This allows you to define and deploy Kubernetes resources within Bicep.

  • The namespace property determines where to deploy Kubernetes resources by default.
  • The kubeConfig property is not currently used and can remain as an empty string (''):
@description('Specifies Kubernetes namespace for the user.')
param namespace string = 'default-demo'

extension kubernetes with {
  kubeConfig: ''
  namespace: namespace
}

Step 2: Add a Kubernetes secret resource

Add a Kubernetes secret to your app.bicep file. This secret will contain a small amount of sensitive data such as a password, a token, or a key:

resource secret 'core/Secret@v1' = {
  metadata: {
    name: 'my-secret'
  }
  stringData: {
    'my-secret-key': 'my-secret-value'
  }
}

Refer to the Kubernetes overview page for additional information about available types.

Step 3: Add a container and use the secret you just defined

Add a Radius container to your application:

// Import the set of Radius resources (Applications.*) into Bicep
extension radius

@description('The app ID of your Radius Application. Set automatically by the rad CLI.')
param application 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
        }
      }
      env: {
        SECRET: {
          value: base64ToString(secret.data['my-secret-key'])
        }
      }
    }
  }
}

Step 4: Deploy your Radius Application

Deploy 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... 

...                  demo            Applications.Core/containers

Deployment Complete

Resources:
    demo            Applications.Core/containers

Starting log stream...

Open http://localhost:3000 to view the Radius demo container. Then navigate to the Container Metadata tab and the Environment variables section which are located near the bottom of the Radius demo webpage, there will be row dedicated to your Kubernetes secret object:

You can also prove the deployed Kubernetes secret was created by using kubectl, and running the following command with your specific secret name:

kubectl describe secret my-secret  -n default-demo

Your console output should contain the following section:

Name:         my-secret
Namespace:    default-demo
Labels:       <none>
Annotations:  <none>

Type:  Opaque

Data
====
my-secret-key:  15 bytes

Cleanup

To delete your Radius specific Kubernetes resources you’ll need to run:

rad app delete -a demo

Once your Radius Application has been deleted you can delete the Kubernetes Secret:

kubectl delete secret my-secret -n default-demo

Your console output should look similar to:

secret "my-secret" deleted

rad app delete does not delete non-Radius resources that are not directly part of a Radius Application, such as Kubernetes resources. These resources require an additional cleanup step.

Further reading