Serverless Event-Driven Data Processing on Cloud Run

Question

Pulumi · Accepted Answer

Creating a serverless event-driven data processing system on Google Cloud Run involves creating a Cloud Run service that can process events, likely by integrating with other Google Cloud services such as Pub/Sub for event ingestion and Cloud Storage for data storage.

To set up this system using Pulumi, you need to do the following steps:

1. Define a Cloud Run service which will contain the code for processing the events.
2. Define a Pub/Sub topic that will send events to the Cloud Run service.
3. Configure the Pub/Sub trigger on the Cloud Run service to accept messages from the Pub/Sub topic.
4. Optionally, set up Cloud Storage as a place to save or retrieve data if needed.

Below is a Pulumi program that defines a Google Cloud Run service and a Pub/Sub topic configured to trigger that service in response to messages. This program is written for Pulumi in Python. It assumes you already have Docker images for your Cloud Run service ready to be deployed that includes the code to handle the events.

```python
import pulumi
import pulumi_gcp as gcp

# Create a Cloud Run service.
# The `google-native.run/v2.Service` resource is used to define a new Cloud Run service.
# Refer to the official Pulumi documentation for more details:
# https://www.pulumi.com/registry/packages/google-native/api-docs/run/v2/service/
cloud_run_service = gcp.cloudrunv2.Service("data-processing-service",
    project=gcp.config.project,  # Use the GCP project specified in your Pulumi configuration
    location="us-central1",      # Location where the service will be hosted
    template={
        "containers": [{
            "image": "gcr.io/my-project/my-image:latest",  # Replace with the image containing your data processing code
        }],
        "scaling": {
            "minInstanceCount": 1,
            "maxInstanceCount": 100,
        },
    })

# Create a Pub/Sub topic that will be used to trigger the Cloud Run service.
# The `gcp.pubsub.Topic` resource is used to define a new Pub/Sub topic.
# For more detail, refer to the official Pulumi documentation:
# https://www.pulumi.com/registry/packages/gcp/api-docs/pubsub/topic/
pubsub_topic = gcp.pubsub.Topic("data-processing-topic")

# Create a Pub/Sub subscription for the Cloud Run service trigger.
# The `gcp.cloudrun.Trigger` resource is a high-level Pulumi component which encapsulates
# the creation of both a Pub/Sub subscription and the necessary IAM binding for Cloud Run.
# Check the official documentation for more details:
# https://www.pulumi.com/registry/packages/gcp/api-docs/cloudrun/trigger/
cloud_run_trigger = gcp.cloudrun.Trigger("data-processing-trigger",
    target_service=cloud_run_service.name,
    pubsub_topic=pubsub_topic.name)

# Export the Cloud Run service URL and Pub/Sub topic name as stack outputs.
# Stack outputs can be viewed after deployment and are useful for accessing or integrating
# with the deployed resources.
pulumi.export("service_url", cloud_run_service.statuses["url"])
pulumi.export("topic_name", pubsub_topic.name)
```

In the above code:
- The Cloud Run service is defined with a specific Docker image that should be stateless and event-driven. It will process incoming events.
- The Pub/Sub topic is the channel for event ingestion. When a message is published to this topic, it triggers the service.
- The Cloud Run trigger connects the Pub/Sub topic to the service so that any message in the topic will invoke the service.

This setup provides a base for an event-driven data processing system. The containers in the Cloud Run service need to include code that can handle and process the incoming Pub/Sub messages. You might want to set environment variables or pass secrets, depending on the needs of your processing logic which can also be defined in the service template.

Remember to replace `"gcr.io/my-project/my-image:latest"` with the actual path to the Docker image that includes your event processing logic.

Deploying this program using Pulumi will create the Cloud Run service, the Pub/Sub topic, and configure everything so that messages on the topic will trigger the service. To interact with and manage your Pulumi stacks, you can use the Pulumi CLI or Pulumi Console.