What does Azure Private Link provide for Azure Cache for Redis in TypeScript

Question

Pulumi · Accepted Answer

Azure Private Link is a service that enables Azure services like Azure Cache for Redis to be accessed privately within a virtual network. The primary goal is to provide secure and private access by ensuring that the traffic between your Azure service and the virtual network stays on the Microsoft Azure backbone network.

When you use Azure Private Link with Azure Cache for Redis, it allows you to set up a private endpoint within your virtual network. This creates a secure connection from the virtual network to the Azure Cache for Redis service.

To setup an Azure Private Link to Azure Cache for Redis in TypeScript using Pulumi, you would typically need to:

1. Create an instance of Azure Cache for Redis.
2. Setup a Private Endpoint Connection resource pointing to the Azure Cache for Redis Service.
3. Configure the necessary DNS settings so that the applications within the VNet resolve the Private Link as opposed to the public endpoint.

Let’s write a TypeScript program using Pulumi to configure a Private Endpoint for Azure Cache for Redis. We will be using the `azure-native` provider which is the Pulumi provider for creating and managing resources in Azure using Pulumi.

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as azure from "@pulumi/azure-native";

// Set up an Azure Resource Group
const resourceGroup = new azure.resources.ResourceGroup("myResourceGroup");

// Deploy an Azure Cache for Redis instance
const redisCache = new azure.cache.Redis("myCacheForRedis", {
    resourceGroupName: resourceGroup.name,
    location: resourceGroup.location,
    sku: {
        name: "Standard",
        family: "C",
        capacity: 0  // The size of the Redis cache to deploy.
    },
    enableNonSslPort: false, // Ensuring only SSL ports are used.
});

// Create a Private Endpoint for the Azure Cache for Redis
const privateEndpoint = new azure.network.PrivateEndpoint("myPrivateEndpoint", {
    resourceGroupName: resourceGroup.name,
    location: resourceGroup.location,
    // The subresource names for Azure Cache for Redis can be different, typically "redisCache" or similar
    // This requires validation or reference to the documentation.
    privateLinkServiceConnections: [{
        name: "myPLSConnection", // Name for the connection.
        privateLinkServiceConnectionState: {
            status: "Approved",
            description: "Auto-approved connection",
            actionsRequired: "None",
        },
        privateLinkServiceId: redisCache.id, // Link to the Redis cache resource.
    }],
    // Reference a subnet where the Private Endpoint should be created.
    // Ensure that the subnet is configured with `privateEndpointNetworkPolicies` enabled.
    subnet: {
        id: "/subscriptions/{subscription-id}/resourceGroups/{rg}/providers/Microsoft.Network/virtualNetworks/{vnet}/subnets/{subnet}", // The subnet ID should be replaced with the actual values.
    },
});

// Export the primary connection string for the Redis Cache, make sure to use the private endpoint when connecting.
export const primaryConnectionString = redisCache.primaryConnectionString;
export const privateEndpointId = privateEndpoint.id;

```

Make sure to replace placeholder values like `{subscription-id}`, `{rg}`, `{vnet}` and `{subnet}` with actual values that correspond to your Azure subscription and network configuration.

In this program:

- We create a new resource group to house our Azure resources.
- We then create a Redis cache instance. The `sku` parameter is used to specify the pricing tier, size, and family of the Redis instance.
- We setup a private endpoint by creating a `PrivateEndpoint` resource. The `privateLinkServiceConnections` array contains configuration for connecting to the Redis Cache service through the private link.

Finally, we export the primary connection string for the Redis Cache. This connection string would normally include a DNS name that resolves publicly, but with a Private DNS Zone (not implemented in this code), the DNS name will resolve to the private IP address provided to the Private Endpoint, ensuring traffic stays within your virtual network.

For a full implementation, you would also need to configure:

- The required DNS settings using a Private DNS Zone that corresponds to the Redis Cache's private link.
- Proper Network Security Group (NSG) rules in your VNet to allow traffic to the Private Endpoint.

Remember to consult the [Azure Cache for Redis](https://www.pulumi.com/registry/packages/azure-native/api-docs/cache/redis/) documentation and the [Private Endpoint](https://www.pulumi.com/registry/packages/azure-native/api-docs/network/privateendpoint/) documentation on Pulumi's website for detailed information about the resources and properties used.

**Note:** Provisioning Azure resources with Pulumi requires an active Azure subscription and authentication setup. Ensure that the Pulumi CLI is authenticated to Azure using the `az login` command or by setting appropriate environment variables.