Queue-triggered Azure Functions for Real-Time AI Analytics

Question

Pulumi · Accepted Answer

To create queue-triggered Azure Functions for real-time AI analytics, you will need Azure Functions that are triggered by messages arriving in an Azure Storage Queue. Azure Functions is a serverless compute service that enables you to run event-triggered code without having to explicitly provision or manage infrastructure.

Here's how to set up queue-triggered Azure Functions using Pulumi with Python:

1. **Azure Functions**: This is where your code will run. You'll write a function that gets triggered when a new message is put on a queue.
2. **Azure Storage Queue**: This queue service will be used to trigger the function. Every time a new message is added to the queue, the Azure Function will be triggered and process that message.

The following Pulumi Python code demonstrates how to set up Azure Functions and Storage Queue:

- `StorageAccount`: Defines an Azure Storage account where the queue will live.
- `StorageQueue`: Creates the queue that will trigger the function.
- `AppServicePlan`: Defines the kind of serverless/managed service where the function will run.
- `StorageAccount`: An Azure Storage account is required to store the Azure Function's code.
- `FunctionApp`: Defines the Azure Function itself, including the connection to the storage queue.

Below is a detailed Pulumi program in Python that sets up queue-triggered Azure Functions:

```python
import pulumi
import pulumi_azure as azure

# Create an Azure Resource Group
resource_group = azure.core.ResourceGroup('resource_group')

# Create an Azure Storage Account for the function's code & a Queue to trigger the function
storage_account = azure.storage.Account('storageaccount',
    resource_group_name=resource_group.name,
    account_replication_type='LRS',
    account_tier='Standard')

storage_queue = azure.storage.Queue('queue',
    storage_account_name=storage_account.name,
    resource_group_name=resource_group.name)

# Create an Azure App Service Plan for hosting the function
app_service_plan = azure.appservice.Plan('appserviceplan',
    resource_group_name=resource_group.name,
    kind='FunctionApp',
    sku={
        'tier': 'Dynamic',
        'size': 'Y1'
    })

# Define connection_string to be used by the function app to the storage account
# Connection string is needed for the function app to access the queue
connection_string = pulumi.Output.all(storage_account.primary_connection_string, storage_account.name).apply(
    lambda args: f"DefaultEndpointsProtocol=https;AccountName={args[1]};EndpointSuffix=core.windows.net;AccountKey={args[0].split('AccountKey=')[1].split(';')[0]}")

# Create an Azure Function App
function_app = azure.appservice.FunctionApp('functionapp',
    resource_group_name=resource_group.name,
    app_service_plan_id=app_service_plan.id,
    storage_account_name=storage_account.name,
    storage_account_access_key=storage_account.primary_access_key,
    # Setting the function app to be triggered by storage queue messages
    app_settings={
        'AzureWebJobsStorage': connection_string,
        'FUNCTIONS_EXTENSION_VERSION': '~3',
        'FUNCTIONS_WORKER_RUNTIME': 'python',
        'WEBSITE_RUN_FROM_PACKAGE': '1',
        'QueueName': storage_queue.name,
    },
    # The function code would be deployed from a source control or package URL.
    # For simplicity, WEBSITE_RUN_FROM_PACKAGE setting is set to 1, assuming deployment through other means.
    # Replace with actual deployment method as needed.
)

# Export the Function App URL to access it after deployment
pulumi.export('function_app_url', function_app.default_hostname.apply(lambda url: f'https://{url}'))
pulumi.export('storage_queue_name', storage_queue.name)

```

This code does the following:

- Initializes a new Azure resource group to contain all the resources.
- Provisions an Azure Storage Account and a queue within it. Messages sent to this queue will trigger the function.
- Creates an Azure App Service Plan with a "Dynamic" SKU, which is the billing model for Azure Functions (you're billed based on execution count and duration).
- Constructs the Azure Function App itself and configures it with app settings, including the connection string to the Storage Account and the queue name that triggers the function.
- Sets the `WEBSITE_RUN_FROM_PACKAGE` setting to 1 for simplicity. This would normally be replaced with an actual deployment URL indicating where your function's code package can be downloaded by Azure.
- Exports the URL of the function app and the name of the storage queue.

Remember to replace the `"WEBSITE_RUN_FROM_PACKAGE"` value with the URL of your actual code package if you're not using another deployment method. You will also need the actual function code that gets triggered, which should be included in the deployment package referred to in the `WEBSITE_RUN_FROM_PACKAGE` setting.

Deploying this Pulumi program will create the necessary infrastructure on Azure, but you still need to write and deploy the code for the function app that will be executed when messages are put onto the queue. Ensure your function code includes logic to pull messages from the queue and perform real-time analytics as required.