Using azure eventgrid with vnet

Question

Pulumi · Accepted Answer

Using Azure Event Grid with a Virtual Network (VNet) allows you to securely and privately route your events to services within a VNet. This can be done by configuring an Event Grid Topic or Domain and integrating it with Azure services that support VNet integration, like Azure Functions or Logic Apps.

To get started, you will first need to create an Event Grid Topic or Domain. This entity will be the endpoint to which your event publishers will send events. Then, you can provision an Azure service, such as an Azure Function, within your VNet to handle those events. Azure Event Grid can deliver events directly to Azure services that are configured with service endpoints or private endpoints within a VNet.

Here's a basic Pulumi program written in TypeScript that:

1. Sets up an Azure Resource Group.
2. Creates an Event Grid Domain within that Resource Group – an Event Grid Domain provides a way to aggregate multiple topics into a single endpoint.
3. Sets up a VNet along with a subnet.
4. Assigns the Event Grid Domain to the subnet.

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

// Create a resource group for all the resources
const resourceGroup = new azure.core.ResourceGroup("eventgrid-rg", {
    location: "West US",
});

// Create a Virtual Network
const vnet = new azure.network.VirtualNetwork("eventgridVNet", {
    addressSpaces: ["10.0.0.0/16"],
    location: resourceGroup.location,
    resourceGroupName: resourceGroup.name,
});

// Create a subnet within the Virtual Network for Event Grid
const subnet = new azure.network.Subnet("eventgridSubnet", {
    resourceGroupName: resourceGroup.name,
    addressPrefix: "10.0.0.0/24",
    virtualNetworkName: vnet.name,
    serviceEndpoints: [{ service: "Microsoft.EventGrid" }], // Enable service endpoint for Event Grid
});

// Create an Event Grid Domain
const eventGridDomain = new azureEventGrid.Domain("example-domain", {
    location: resourceGroup.location,
    resourceGroupName: resourceGroup.name,
    // Configure the domain's properties as needed. For instance:
    // You can use inboundIpRules to restrict traffic to a set of IP addresses if needed
});

// Output the Event Grid Domain endpoint
export const endpoint = eventGridDomain.endpoint;

// When configuring your Azure services in the VNet (e.g., Azure Functions),
// use event subscriptions with the Event Grid Domain as the endpoint to
// route and process events within your VNet.
// Ensure that you also set up the necessary network security rules to allow traffic as needed.

// Note that the actual handling of events and the setup of listeners
// inside the VNet are not covered in this setup and need to be done separately.
```

In the above program, we first create a Resource Group that will contain all Azure resources. This is a logical grouping that allows you to manage all the deployed resources together.

Then, we define a Virtual Network with an address space, specifying an IP range. Within this VNet, we create a subnet, and we specify that the subnet should have a service endpoint for Event Grid. This allows the subnet to be the target for an Event Grid handler like Azure Functions, securely within your VNet.

Following that, we create an Event Grid Domain which acts as a single point for publishing events that will be distributed to registered subscribers. It's set up within the same resource group and configured at the same location. In real scenarios, you might also want to constrain which IPs can send events to your domain using `inboundIpRules`.

At the end, we expose the `endpoint` URL of the Event Grid Domain as an output of the Pulumi program. This URL is used by event publishers to send events to your domain.

Keep in mind that this code sets the necessary infrastructure for integrating Event Grid with a VNet, but you still need to create event handlers (such as Azure Functions) within your VNet that will be triggered by the events sent to the Event Grid Domain, and subscribe them to the domain. Additionally, configure your network security to allow the necessary traffic to and from the services within your VNet.

To set up event handlers and subscriptions, and to apply detailed network security configurations, you'll need to extend this basic configuration with additional resources and properties.