Quickstart: Receive direct events from Cloud Storage (gcloud CLI) | Eventarc Standard

Receive direct events from Cloud Storage (gcloud CLI)

Standard

This quickstart shows you how to receive direct events from Cloud Storage (without using Cloud Audit Logs) in an unauthenticated Cloud Run service using Eventarc.

You can configure the triggering of notifications in response to various events inside a Cloud Storage bucket—object creation, deletion, archiving, and metadata updates. For more information, see Create a trigger to route Cloud Storage events to Cloud Run.

In this quickstart, you:

Create a Cloud Storage bucket to be the event source.
Deploy an event receiver service to Cloud Run.
Create an Eventarc trigger.
Generate an event by uploading a file to the Cloud Storage bucket, and view it in the Cloud Run logs.

Before you begin

SERVICE_ACCOUNT="$(gcloud storage service-agent --project=PROJECT_ID)" gcloud projects add-iam-policy-binding PROJECT_ID \ --member="serviceAccount:${SERVICE_ACCOUNT}" \ --role='roles/pubsub.publisher'

Create a Cloud Storage bucket

Create a Cloud Storage bucket to use as the event source:

gcloud storage buckets create gs://PROJECT_ID-bucket/ --location=us-central1

After the event source is created, you can deploy the event receiver service on Cloud Run.

Deploy the event receiver service to Cloud Run

Deploy a Cloud Run service that will receive and log events using a prebuilt image, us-docker.pkg.dev/cloudrun/container/hello:

gcloud run deploy helloworld-events \
    --image=us-docker.pkg.dev/cloudrun/container/hello \
    --allow-unauthenticated

When the deployment succeeds, the command line displays the service URL.

Now that you have deployed a event receiver service called helloworld-events to Cloud Run, you can set up your trigger.

Create an Eventarc trigger

The Eventarc trigger sends events from the Cloud Storage bucket to the helloworld-events Cloud Run service.

Create a trigger that filters Cloud Storage events and that uses the Compute Engine default service account.
```
  gcloud eventarc triggers create storage-events-trigger \
      --destination-run-service=helloworld-events \
      --destination-run-region=us-central1 \
      --event-filters="type=google.cloud.storage.object.v1.finalized" \
      --event-filters="bucket=PROJECT_ID-bucket" \
      --service-account=PROJECT_NUMBER-compute@developer.gserviceaccount.com
```
This creates a trigger called storage-events-trigger.

Note that when creating an Eventarc trigger for the first time in a Google Cloud project, there might be a delay in provisioning the Eventarc service agent. This issue can usually be resolved by attempting to create the trigger again. For more information, see Permission denied errors.

To confirm storage-events-trigger was successfully created, run:

  gcloud eventarc triggers list --location=us-central1

The output is similar to the following:

 NAME                    TYPE                                      DESTINATION_RUN_SERVICE  DESTINATION_RUN_PATH  ACTIVE
 storage-events-trigger  google.cloud.storage.object.v1.finalized  helloworld-events                              Yes

Generate and view an event

To generate an event, upload a text file to Cloud Storage:
```
 echo "Hello World" > random.txt
 gcloud storage cp random.txt gs://PROJECT_ID-bucket/random.txt
```
The upload generates an event and the Cloud Run service logs the event's message.

To view the log entry, filter the log entries, and return the output in JSON format:

gcloud logging read 'jsonPayload.message: "Received event of type google.cloud.storage.object.v1.finalized."'

Look for a log entry similar to the following:

jsonPayload:
  event:
  ...
  eventType: google.cloud.storage.object.v1.finalized
  message: |
    Received event of type google.cloud.storage.object.v1.finalized. Event data: {
      "kind": "storage#object",
      "id": "PROJECT_ID-bucket/random.txt/1713970683868432",
      "selfLink": "https://www.googleapis.com/storage/v1/b/PROJECT_ID-bucket/o/random.txt",
      "name": "random.txt",
      "bucket": "PROJECT_ID-bucket",
      ...
    }

Congratulations! You have successfully deployed an event receiver service to Cloud Run, created an Eventarc trigger, generated an event from Cloud Storage, and viewed it in the Cloud Run logs.

Clean up

When you finish the tasks that are described in this document, you can avoid continued billing by deleting the resources that you created.

You can:

Alternatively, you can delete your Google Cloud project to avoid incurring charges. Deleting your Google Cloud project stops billing for all the resources used within that project.

Delete a Google Cloud project:

gcloud projects delete PROJECT_ID

If you plan to explore multiple tutorials and quickstarts, reusing projects can help you avoid exceeding project quota limits.