Topic Filtering for AI Event Routing in Azure Service Bus

Question

Pulumi · Accepted Answer

To implement topic filtering for AI event routing in Azure Service Bus using Pulumi, you'll first need to create a Service Bus namespace, a topic within that namespace, and subscriptions with rules for filtering messages. Here's how you can achieve this using Pulumi with the `azure-native` package in Python:

1. **Service Bus Namespace**: This is the container for all messaging components. Namespaces are a scoping container for topics and subscriptions.
2. **Service Bus Topic**: A topic is a communication channel to which messages are sent.
3. **Service Bus Subscription**: Subscriptions are used to receive messages sent to a topic.
4. **Service Bus Rules**: Subscriptions can have rules that determine which messages to the subscription should receive based on the message properties.

The following program demonstrates how to set up these resources. Comments in the code provide additional context on each step.

```python
import pulumi
import pulumi_azure_native.servicebus as servicebus

# Replace with your resource group name and location
resource_group_name = "my-resource-group"
location = "East US"

# Step 1: Create the Service Bus Namespace
service_bus_namespace = servicebus.Namespace("myServiceBusNamespace",
    resource_group_name=resource_group_name,
    location=location,
    sku=servicebus.SBSkuArgs(
        name="Standard"  # Pricing tier of the namespace (Basic, Standard, or Premium)
    )
)

# Step 2: Create the Service Bus Topic
service_bus_topic = servicebus.Topic("myServiceBusTopic",
    namespace_name=service_bus_namespace.name,
    resource_group_name=resource_group_name
)

# Step 3: Create the Service Bus Subscription
service_bus_subscription = servicebus.Subscription("myServiceBusSubscription",
    topic_name=service_bus_topic.name,
    namespace_name=service_bus_namespace.name,
    resource_group_name=resource_group_name
)

# Step 4: Create the Service Bus Rule for Message Filtering
# This rule only allows messages with the property 'eventType' set to 'AIEvent'
service_bus_topic_rule = servicebus.Rule("myServiceBusRule",
    rule_name="AIEventTypeRule",
    subscription_name=service_bus_subscription.name,
    topic_name=service_bus_topic.name,
    namespace_name=service_bus_namespace.name,
    resource_group_name=resource_group_name,
    sql_filter=servicebus.SqlFilterArgs(
        sql_expression="eventType = 'AIEvent'"  # SQL expression for filtering
    )
)

# Export the primary connection string to enable sending and receiving messages
primary_connection_string = pulumi.Output.all(service_bus_namespace.resource_group_name, service_bus_namespace.name).apply(
    lambda args: servicebus.list_namespace_keys(
        resource_group_name=args[0],
        namespace_name=args[1],
        authorization_rule_name="RootManageSharedAccessKey"  # The default rule that is created along with the Service Bus Namespace
    )
).apply(lambda list_namespace_keys_result: list_namespace_keys_result.primary_connection_string)

pulumi.export('primaryConnectionString', primary_connection_string)
```

In this program, you provide the essential components necessary for AI event routing on Azure Service Bus:

- A `Namespace` is created to serve as the container for your messaging components.
- A `Topic` is defined within that namespace. Think of it as a broadcast channel that will receive messages from your AI application.
- A `Subscription` is hooked to the topic to receive copies of the messages sent to the Topic.
- A `Rule` is added to the subscription, filtered based on your desired criteria. This example filters based on a custom `eventType` property, but it could be any property or combination you need for your AI event routing logic.

Finally, you export the primary connection string as `primaryConnectionString` so you can use it to send and receive messages from client applications.

Remember, before running this Pulumi program, you should have the Pulumi CLI installed, be logged in, and have the appropriate permissions set up in your Azure account.