How To: Service to service networking

Learn how your Radius services can communicate with each other
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This guide will show you how two services can communicate with each other. In this example, we will have a frontend container service that communicates with a backend container service.

Prerequisites

Step 1: Define the services

First, define the containers in a file named app.bicep. We will define two services: frontend and backend:

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import radius as rad

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

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

resource backend 'Applications.Core/containers@2023-10-01-preview' = {
  name: 'backend'
  properties: {
    application: application
    container: {
      image: 'nginx:latest'
      ports: {
        web: {
          containerPort: 80
        }
      }
    }
  }
}

Note the frontend container doesn’t yet have a connection to the backend container. We will add that in the next step.

Step 2: Add a connection

With the services defined, we can now add the connection between them. Add a connection to frontend:

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resource frontend 'Applications.Core/containers@2023-10-01-preview' = {
  name: 'frontend'
  properties: {
    application: application
    container: {
      image: 'ghcr.io/radius-project/samples/demo:latest'
      ports: {
        web: {
          containerPort: 3000
        }
      }
    }
    connections: {
      backend: {
        source: 'http://backend:80'
      }
    }
  }
}

Step 3: Deploy the application

Deploy the application using the rad deploy command:

rad run app.bicep -a networking-demo

You should see the application deploy successfully and the log stream start:

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

Deployment In Progress...

Completed            backend         Applications.Core/containers
Completed            frontend        Applications.Core/containers

Deployment Complete

Resources:
    backend         Applications.Core/containers
    frontend        Applications.Core/containers

Starting log stream...

Step 4: Test the connection

Visit http://localhost:3000 in your browser. You should see a connection to the backend container, along with the environment variables that have automatically been set on the frontend container:

Done

You have successfully added a connection between two containers. Make sure to delete your application to clean up the containers:

rad app delete networking-demo -y