Scalable Event-Driven AI Workflows with Azure Event Grid

Question

Pulumi · Accepted Answer

To create scalable event-driven AI workflows with Azure Event Grid using Pulumi, you will utilize various Azure services. Azure Event Grid is a fully managed event routing service that provides reliable message delivery at massive scale. It enables you to build reactive, event-driven architectures where events generated by Azure services or third-party resources can be subscribed to and handled efficiently.

Here's a high-level overview of the approach you might take:

1. Set up an Azure Event Grid Topic as an event source, which will publish events.
2. Create an Azure Event Grid Subscription, pointing to the Topic, that triggers upon receiving an event.
3. The Event Subscription will forward events to an Azure Function App, where you can execute custom logic (such as AI processing) upon event reception.
4. The Azure Function can then scale automatically and process the data asynchronously based on the incoming event volume.

The following Pulumi program initializes an Event Grid Domain, a Topic within that domain, and subscribes an Azure Function to the topic via an Event Grid Subscription. Events sent to the Topic will trigger the subscribed Azure Function. We are using the higher-level `azure-native` package in this example:

```python
import pulumi
import pulumi_azure_native.eventgrid as eventgrid
import pulumi_azure_native.resources as resources
import pulumi_azure_native.web as web
import pulumi_azure_native.storage as storage

# Creating a new resource group
resource_group = resources.ResourceGroup('resource_group')

# Setting up a storage account, needed for Azure Functions
storage_account = storage.StorageAccount('storageaccount',
    resource_group_name=resource_group.name,
    sku=storage.SkuArgs(
        name=storage.SkuName.STANDARD_LRS
    ),
    kind=storage.Kind.STORAGE_V2
)

# Creating an Azure Function App where you will deploy your event-driven logic
function_app = web.WebApp('functionapp',
    resource_group_name=resource_group.name,
    server_farm_id='/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/serverfarms/{serverFarmId}', # Replace with actual IDs
    site_config=web.SiteConfigArgs(
        app_settings=[
            web.NameValuePairArgs(name='AzureWebJobsStorage', value=storage_account.primary_connection_string),
            web.NameValuePairArgs(name='FUNCTIONS_EXTENSION_VERSION', value='~2'),
            web.NameValuePairArgs(name='FUNCTIONS_WORKER_RUNTIME', value='python'),
            web.NameValuePairArgs(name='WEBSITE_RUN_FROM_PACKAGE', value='1'),
        ],
    ),
    https_only=True,
)

# Creating an Event Grid Domain
event_grid_domain = eventgrid.Domain('eventgrid-domain',
    resource_group_name=resource_group.name,
    location=resource_group.location
)

# Creating an Event Grid Topic within the Event Grid Domain
event_grid_topic = eventgrid.DomainTopic('eventgrid-topic',
    resource_group_name=resource_group.name,
    domain_name=event_grid_domain.name,
    topic_name='topic1'
)

# Creating an Event Grid Subscription to the Topic
event_subscription = eventgrid.EventSubscription('event-subscription',
    scope=event_grid_topic.id,
    destination=eventgrid.WebHookEventSubscriptionDestinationArgs(
        endpoint_url=function_app.default_host_name.apply(lambda endpoint: f'https://{endpoint}/runtime/webhooks/eventgrid?functionName=YourFunctionName&code=YourFunctionKey')
    ),
    filter=eventgrid.EventSubscriptionFilterArgs(
        # Customize your filter accordingly
        included_event_types=['Microsoft.Storage.BlobCreated'],
        is_subject_case_sensitive=False
    )
)

# Exporting relevant endpoints
pulumi.export('FunctionAppEndpoint', function_app.default_host_name)
pulumi.export('EventGridTopicEndpoint', event_grid_topic.name)
```

Before deploying this program, please replace the placeholders `{...}` with your actual Azure subscription ID, resource group name, and server farm ID. You can find this information in your Azure portal. Additionally, you would want to replace `YourFunctionName` and `YourFunctionKey` with the name of the function in your Azure Function App and the respective function key.

This program will do the following:

- Create a resource group, which is a container that holds related resources for an Azure solution.
- Set up a storage account required for the Azure Functions app to maintain state and other information.
- Provision an Azure Function App with the necessary configuration, which will contain the actual business logic for event processing. This is where your AI code will live.
- Set up an Event Grid Domain, which is a management tool for handling large numbers of related Event Grid Topics.
- Create an Event Grid Topic within the domain, which represents a channel where the publisher sends events.
- Subscribe to the Event Grid Topic with an Event Subscription, which filters for specific event types and routes them to the Azure Function App endpoint.

Each event that matches the filter criteria will trigger the specified Azure Function, enabling you to process the event with your AI workflow code.

When you run this program with the Pulumi CLI, Pulumi will perform an upsert operation; it will create these resources if they do not exist or update them if they do. After the deployment, the exported endpoints will be displayed, which can be used to interact with the Function App and the Event Grid Topic.