Console
    Contact Us Start free

    Use Eventarc to receive events from Cloud Storage

    This tutorial shows you how to deploy a containerized application using an authenticated Cloud Run service that receives events through Eventarc.

    By specifying filters for an Eventarc trigger, you can configure the routing of events, including the event source and the event target. In this case, an update to a Cloud Storage bucket triggers the event and a request is sent to your Cloud Run service in the form of an of HTTP request.

    Objectives

    In this tutorial, you will:

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

    2. Deploy an event receiver service to Cloud Run that requires authenticated invocations.

    3. Create an Eventarc trigger that routes events from the Cloud Storage bucket to the Cloud Run service.

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

    Costs

    In this document, you use the following billable components of Google Cloud:

    To generate a cost estimate based on your projected usage, use the pricing calculator .

    New Google Cloud users might be eligible for a free trial .

    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. If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity .

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

      gcloud  
init

    5. Create or select a Google Cloud 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.

    6. Verify that billing is enabled for your Google Cloud project .

    7. Install the Google Cloud CLI.

    8. If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity .

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

      gcloud  
init

    10. Create or select a Google Cloud 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.

    11. Verify that billing is enabled for your Google Cloud project .

      12.
    12. If you are not using Cloud Shell, update the Google Cloud CLI components and log in using your account: 
      gcloud  
components  
update
gcloud  
auth  
login
    13. Enable the APIs: 
      gcloud  
services  
 enable 
  
artifactregistry.googleapis.com  
 \ 
  
cloudbuild.googleapis.com  
 \ 
  
eventarc.googleapis.com  
 \ 
  
run.googleapis.com  
 \ 
  
storage.googleapis.com
    14. Set the configuration variables used in this tutorial: 
       export 
  
 REGION 
 = 
us-central1
gcloud  
config  
 set 
  
run/region  
 ${ 
 REGION 
 } 
gcloud  
config  
 set 
  
run/platform  
managed
gcloud  
config  
 set 
  
eventarc/location  
 ${ 
 REGION 
 }
    15. You or your administrator must grant the deployer account, the trigger identity, and optionally, the Pub/Sub service agent the following IAM roles.

      Required roles for the trigger identity

      1. 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:

         PROJECT_NUMBER 
-compute@developer.gserviceaccount.com

        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 .

      2. By default, Cloud Run services are only callable by Project Owners, Project Editors, and Cloud Run Admins and Invokers. You can control access on a per-service basis ; however, for testing purposes, grant the Cloud Run Invoker role ( run.invoker ) on the Google Cloud project to the Compute Engine service account. This grants the role on all Cloud Run services and jobs in a project. 
        gcloud  
projects  
add-iam-policy-binding  
 PROJECT_ID 
  
 \ 
  
--member = 
serviceAccount: PROJECT_NUMBER 
-compute@developer.gserviceaccount.com  
 \ 
  
--role = 
roles/run.invoker

        Note that if you create a trigger for an authenticated Cloud Run service without granting the Cloud Run Invoker role, the trigger is created successfully and is active. However, the trigger will not work as expected and a message similar to the following appears in the logs:

        The request was not authenticated. Either allow unauthenticated invocations or set the proper Authorization header.
      3. 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: PROJECT_NUMBER 
-compute@developer.gserviceaccount.com  
 \ 
  
--role = 
roles/eventarc.eventReceiver

      Optional role for the Pub/Sub service agent

      • 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:service- PROJECT_NUMBER 
@gcp-sa-pubsub.iam.gserviceaccount.com  
 \ 
  
--role = 
roles/iam.serviceAccountTokenCreator

    Create an Artifact Registry standard repository

    Create an Artifact Registry standard repository to store your container image:

    gcloud  
artifacts  
repositories  
create  
 REPOSITORY 
  
 \ 
  
--repository-format = 
docker  
 \ 
  
--location = 
 $REGION

    Replace REPOSITORY with a unique name for the repository.

    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 an event receiver to Cloud Run

    Deploy a Cloud Run service that receives and logs events.

    1. Clone the GitHub repository:

      Node.js

      git  
clone  
https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git

      Alternatively, you can download the sample as a zip file and extract it.

      Python

      git  
clone  
https://github.com/GoogleCloudPlatform/python-docs-samples.git

      Alternatively, you can download the sample as a zip file and extract it.

      Go

      git  
clone  
https://github.com/GoogleCloudPlatform/golang-samples.git

      Alternatively, you can download the sample as a zip file and extract it.

      Java

      git  
clone  
https://github.com/GoogleCloudPlatform/java-docs-samples.git

      Alternatively, you can download the sample as a zip file and extract it.

      C#

      git  
clone  
https://github.com/GoogleCloudPlatform/dotnet-docs-samples.git

      Alternatively, you can download the sample as a zip file and extract it.

    2. Change to the directory that contains the Cloud Run sample code:

      Node.js

       cd 
  
nodejs-docs-samples/eventarc/audit-storage/

      Python

       cd 
  
python-docs-samples/eventarc/audit-storage/

      Go

       cd 
  
golang-samples/eventarc/audit_storage/

      Java

       cd 
  
java-docs-samples/eventarc/audit-storage/

      C#

       cd 
  
dotnet-docs-samples/eventarc/audit-storage/

    3. Build the container for the Cloud Run service:

       export 
  
 PROJECT_ID 
 = 
 $( 
gcloud  
config  
get-value  
project ) 
 export 
  
 SERVICE_NAME 
 = 
helloworld-events
gcloud  
builds  
submit  
--tag  
 $REGION 
-docker.pkg.dev/ ${ 
 PROJECT_ID 
 } 
/ REPOSITORY 
/ ${ 
 SERVICE_NAME 
 } 
:v1

    4. Deploy the container image to Cloud Run:

      gcloud  
run  
deploy  
 ${ 
 SERVICE_NAME 
 } 
  
 \ 
  
--image  
 $REGION 
-docker.pkg.dev/ ${ 
 PROJECT_ID 
 } 
/ REPOSITORY 
/ ${ 
 SERVICE_NAME 
 } 
:v1

    5. At the Allow public access to helloworld-events (y/N)? prompt, respond n for "No".

    When you see the Cloud Run service URL, the deployment is complete.

    Create an Eventarc trigger

    The Eventarc trigger sends events from the Cloud Storage bucket to the helloworld-events Cloud Run service. The service requires authentication, and the event should be triggered by a caller that has a service account with the required IAM roles and permissions to use the resource.

    1. Create a trigger that filters Cloud Storage events:

      gcloud  
eventarc  
triggers  
create  
 ${ 
 SERVICE_NAME 
 } 
  
 \ 
  
--destination-run-service = 
 ${ 
 SERVICE_NAME 
 } 
  
 \ 
  
--destination-run-region = 
 ${ 
 REGION 
 } 
  
 \ 
  
--location = 
 ${ 
 REGION 
 } 
  
 \ 
  
--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 helloworld-events .

      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. Confirm that the trigger was successfully created. Note that although your trigger is created immediately, it can take up to two minutes for a trigger to be fully functional.

      gcloud  
eventarc  
triggers  
list  
--location = 
 ${ 
 REGION 
 }

      The output should be similar to the following:

       NAME: helloworld-events
TYPE: google.cloud.storage.object.v1.finalized
DESTINATION: Cloud Run service: helloworld-events
ACTIVE: Yes

    Generate and view an event

    Upload a text file to the Cloud Storage bucket to generate an event which is routed to the Cloud Run service. The Cloud Run service logs the event in the service logs.

    1. 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.

    2. To view the log entry:

      1. Filter the log entries and return the output in JSON format:

        gcloud logging read "resource.labels.service_name=helloworld-events AND textPayload:random.txt" --format=json

      2. Look for a log entry similar to:

        "textPayload": "Detected change in Cloud Storage bucket: objects/random.txt"

    Logs might take a few moments to appear. If you don't see them immediately, check again after a minute.

    Clean up

    If you created a new project for this tutorial, delete the project . If you used an existing project and want to keep it without the changes added in this tutorial, delete the resources created for the tutorial .

    Delete the project

    The easiest way to eliminate billing is to delete the project that you created for the tutorial.

    To delete the project:

    1. In the Google Cloud console, go to the Manage resources page.

      Go to Manage resources

    2. In the project list, select the project that you want to delete, and then click Delete .
    3. In the dialog, type the project ID, and then click Shut down to delete the project.

    Delete tutorial resources

    1. Delete the Cloud Run service you deployed in this tutorial:

      gcloud  
run  
services  
delete  
 SERVICE_NAME

      Where SERVICE_NAME is your chosen service name.

      You can also delete Cloud Run services from the Google Cloud console .

    2. Remove any gcloud CLI default configurations you added during the tutorial setup.

      For example:

      gcloud config unset run/region

      or

      gcloud config unset project

    3. Delete other Google Cloud resources created in this tutorial:

      • Delete the Eventarc trigger: 
        gcloud eventarc triggers delete TRIGGER_NAME
        Replace TRIGGER_NAME with the name of your trigger.

    What's next
    Create a Mobile Website
    View Site in Mobile | Classic
    Share by: