Receive direct events from Cloud Storage (gcloud CLI)

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.

Note: All Cloud Run services are deployed privately by default, which means that they can't be accessed without providing authentication credentials in the request. For projects with domain restricted sharing organization policies, use an authenticated Cloud Run target service rather than one that allows public (unauthenticated) access.

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:

1. Create a Cloud Storage bucket to be the event source.

2. Deploy an event receiver service to Cloud Run.

3. Create an Eventarc trigger.

4. Generate an event by uploading a file to the Cloud Storage bucket, and view it in the Cloud Run logs.

Before you begin

Security constraints defined by your organization might prevent you from completing the following steps. For troubleshooting information, see Develop applications in a constrained Google Cloud environment.

1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
2. Install the Google Cloud CLI.

3. To initialize the gcloud CLI, run the following command:

   gcloud init

4. Create or select a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   • Create a Google Cloud project:

     gcloud projects create PROJECT_ID

     Replace PROJECT_ID with a name for the Google Cloud project you are creating.

   • Select the Google Cloud project that you created:

     gcloud config set project PROJECT_ID

     Replace PROJECT_ID with your Google Cloud project name.

5. Make sure that billing is enabled for your Google Cloud project.

6. Install the Google Cloud CLI.

7. To initialize the gcloud CLI, run the following command:

   gcloud init

8. Create or select a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   • Create a Google Cloud project:

     gcloud projects create PROJECT_ID

     Replace PROJECT_ID with a name for the Google Cloud project you are creating.

   • Select the Google Cloud project that you created:

     gcloud config set project PROJECT_ID

     Replace PROJECT_ID with your Google Cloud project name.

9. Make sure that billing is enabled for your Google Cloud project.

10. Enable the Cloud Run, Cloud Storage, Eventarc, and Pub/Sub APIs.

    gcloud services enable \
    eventarc.googleapis.com \
    pubsub.googleapis.com \
    run.googleapis.com \
    storage.googleapis.com

11. Update gcloud components:

    gcloud components update

12. Sign in using your account:

    gcloud auth login

13. Set the configuration variables used in this quickstart:

    gcloud config set run/region us-central1
    gcloud config set run/platform managed
    gcloud config set eventarc/location us-central1

14. If you are the project creator, you are granted the basic Owner role (roles/owner). By default, this Identity and Access Management (IAM) role includes the permissions necessary for full access to most Google Cloud resources and you can skip this step.

    If you are not the project creator, required permissions must be granted on the project to the appropriate principal. For example, a principal can be a Google Account (for end users) or a service account (for applications and compute workloads). For more information, see the Roles and permissions page for your event destination.

    Required permissions

    To get the permissions that you need to complete this tutorial, ask your administrator to grant you the following IAM roles on your project:

    • Cloud Run Admin (roles/run.admin)
    • Eventarc Admin (roles/eventarc.admin)
    • Logs View Accessor (roles/logging.viewAccessor)
    • Project IAM Admin (roles/resourcemanager.projectIamAdmin)
    • Service Account Admin (roles/iam.serviceAccountAdmin)
    • Service Account User (roles/iam.serviceAccountUser)
    • Service Usage Admin (roles/serviceusage.serviceUsageAdmin)
    • Storage Admin (roles/storage.admin)

    For more information about granting roles, see Manage access to projects, folders, and organizations.

    You might also be able to get the required permissions through custom roles or other predefined roles.

15. Make note of the Compute Engine default service account as you will you attach it to an Eventarc trigger to represent the identity of the trigger for testing purposes. This service account is automatically created after enabling or using a Google Cloud service that uses Compute Engine, and with the following email format:

    [e-mail]

    Replace PROJECT_NUMBER with your Google Cloud project number. You can find your project number on the Welcome page of the Google Cloud console or by running the following command:

    gcloud projects describe PROJECT_ID --format='value(projectNumber)'

    For production environments, we strongly recommend creating a new service account and granting it one or more IAM roles that contain the minimum permissions required and follow the principle of least privilege.

    Note:

    The iam.automaticIamGrantsForDefaultServiceAccounts organization policy constraint prevents the Editor role from being automatically granted to default service accounts. If you created your organization after May 3, 2024, this constraint is enforced by default.

    We strongly recommend that you enforce this constraint to disable the automatic role grant. If you disable the automatic role grant, you must decide which roles to grant to the default service accounts, and then grant these roles yourself.

    If the default service account already has the Editor role, we recommend that you replace the Editor role with less permissive roles. To safely modify the service account's roles, use Policy Simulator to see the impact of the change, and then grant and revoke the appropriate roles.

16. Grant the Eventarc Event Receiver role (roles/eventarc.eventReceiver) on the project to the Compute Engine default service account so that the Eventarc trigger can receive events from event providers.

    gcloud projects add-iam-policy-binding PROJECT_ID \
        --member=serviceAccount:[e-mail] \
        --role=roles/eventarc.eventReceiver

17. Before creating a trigger for direct events from Cloud Storage, grant the Pub/Sub Publisher role (roles/pubsub.publisher) to the Cloud Storage service agent:

    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'

18. If you enabled the Cloud Pub/Sub service agent on or before April 8, 2021, to support authenticated Pub/Sub push requests, grant the Service Account Token Creator role (roles/iam.serviceAccountTokenCreator) to the service agent. Otherwise, this role is granted by default:

    gcloud projects add-iam-policy-binding PROJECT_ID \
        --member=serviceAccount:[e-mail] \
        --role=roles/iam.serviceAccountTokenCreator

Create a Cloud Storage bucket

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

gsutil mb -l us-central1 gs://PROJECT_ID-bucket/

Note: The Cloud Storage bucket must reside in the same Google Cloud project and region or multi-region as the Eventarc trigger.

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.

1. 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=[e-mail]
   

   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.

2. 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
   

Note: Although your trigger is created immediately, it can take up to two minutes for triggers to be fully functional.

Generate and view an event

1. To generate an event, upload a text file to Cloud Storage:

    echo "Hello World" > random.txt
    gsutil cp random.txt gs://PROJECT_ID-bucket/random.txt
   

   The upload generates an event and the Cloud Run service logs the event's message.

2. 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."'
   

3. 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",
         ...
       }
   

   Note: If you don't see a log entry, wait a few minutes and retry the gcloud logging read command. The trigger can take up to two minutes after being created to start filtering events.

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:

1. Delete the Cloud Storage bucket.

2. Delete the Cloud Run service.

3. Delete the Eventarc trigger.

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.

Caution: Deleting a project has the following effects:

• Everything in the project is deleted. If you used an existing project for the tasks in this document, when you delete it, you also delete any other work you've done in the project.
• Custom project IDs are lost. When you created this project, you might have created a custom project ID that you want to use in the future. To preserve the URLs that use the project ID, such as an appspot.com URL, delete selected resources inside the project instead of deleting the whole 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.

What's next

• Build containers for Cloud Run
• Execute a Cloud Run job in a workflow using an Eventarc trigger
• Develop Cloud Run services