Receive events using Cloud Audit Logs (gcloud CLI)

Standard

This quickstart shows you how to receive events from Cloud Storage in an unauthenticated Cloud Run service using Eventarc.

You can complete this quickstart using the Google Cloud CLI. For instructions using the console, see Create a trigger using the Google Cloud console.

In this quickstart, you:

Create a Cloud Storage bucket to be the event source.
Deploy an event receiver service to Cloud Run.
Create an event trigger.
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.

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.

Install the Google Cloud CLI.

To initialize the gcloud CLI, run the following command:

gcloud init

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.

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

Enable the Artifact Registry, Cloud Build, Cloud Run, Eventarc, and Pub/Sub APIs:

gcloud services enable artifactregistry.googleapis.com cloudbuild.googleapis.com run.googleapis.com eventarc.googleapis.com pubsub.googleapis.com

Install the Google Cloud CLI.

To initialize the gcloud CLI, run the following command:

gcloud init

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.

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

Enable the Artifact Registry, Cloud Build, Cloud Run, Eventarc, and Pub/Sub APIs:

gcloud services enable artifactregistry.googleapis.com cloudbuild.googleapis.com run.googleapis.com eventarc.googleapis.com pubsub.googleapis.com

Update gcloud components:
```
gcloud components update
```

Set the configuration variables used in this quickstart:

export REGION=us-central1
gcloud config set run/region ${REGION}
gcloud config set run/platform managed
gcloud config set eventarc/location ${REGION}

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.

Note that by default, Cloud Build permissions include permissions to upload and download Artifact Registry artifacts.
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 Build Editor (roles/cloudbuild.builds.editor)
- 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.

Enable Cloud Audit Logs Admin Read, Data Read, and Data Write Log Types in Google Cloud Storage.
Note that at the project level, you need the roles/owner Identity and Access Management role to configure Data Access audit logs for your Google Cloud resources.
1. Read your project's IAM policy and store it in a file:
```
gcloud projects get-iam-policy PROJECT_ID > /tmp/policy.yaml
```
2. Edit your policy in /tmp/policy.yaml, adding or changing only the Data Access audit logs configuration.
  
  Caution: You must preserve the bindings: and etag: sections without changes. Failure to do so might cause your project to become unusable.
```
auditConfigs:
- auditLogConfigs:
- logType: ADMIN_READ
- logType: DATA_WRITE
- logType: DATA_READ
service: storage.googleapis.com
```
3. Write your new IAM policy:
```
gcloud projects set-iam-policy PROJECT_ID /tmp/policy.yaml
```
  If the preceding command reports a conflict with another change, then repeat these steps, starting with reading the project's IAM policy.
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.

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.
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
```
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
```
Download and install the Git source code management tool.

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

This quickstart uses Cloud Storage as the event source. To create a storage bucket:

gsutil mb -l ${REGION} gs://events-quickstart-PROJECT_ID/

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 receives and logs events. To deploy the sample event receiver service:

Clone the GitHub repository:

Go

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

Java

git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git
cd java-docs-samples/eventarc/audit-storage

.NET

git clone https://github.com/GoogleCloudPlatform/dotnet-docs-samples.git
cd dotnet-docs-samples/eventarc/audit-storage

Node.js

git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git
cd nodejs-docs-samples/eventarc/audit-storage

Python

git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git
cd python-docs-samples/eventarc/audit-storage

Build the container and upload it to Cloud Build:

gcloud builds submit --tag $REGION-docker.pkg.dev/PROJECT_ID/REPOSITORY/helloworld-events:v1

Deploy the container image to Cloud Run:
```
gcloud run deploy helloworld-events \
    --image $REGION-docker.pkg.dev/PROJECT_ID/REPOSITORY/helloworld-events:v1 \
    --allow-unauthenticated
```
When the deployment succeeds, the command line displays the service URL.

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

Create an Eventarc trigger

The Eventarc trigger will send 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 Google Cloud project Compute Engine default service account:
```
gcloud eventarc triggers create events-quickstart-trigger \
    --destination-run-service=helloworld-events \
    --destination-run-region=${REGION} \
    --event-filters="type=google.cloud.audit.log.v1.written" \
    --event-filters="serviceName=storage.googleapis.com" \
    --event-filters="methodName=storage.objects.create" \
    --service-account=PROJECT_NUMBER-compute@developer.gserviceaccount.com
```
This creates a trigger called events-quickstart-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 events-quickstart-trigger was successfully created, run:
```
gcloud eventarc triggers list --location=${REGION}
```
The events-quickstart-trigger is listed with a destination that is the Cloud Run service, helloworld-events.

Generate and view an event

To generate an event, upload a text file to Cloud Storage:
```
 echo "Hello World" > random.txt
 gsutil cp random.txt gs://events-quickstart-PROJECT_ID/random.txt
```
The upload generates an event and the Cloud Run service logs the event's message.
To view the event-related log entries created by your service, run the following command:
```
gcloud logging read 'textPayload: "Detected change in Cloud Storage bucket"'
```
Look for a log entry similar to:
```
Detected change in Cloud Storage bucket: storage.googleapis.com/projects/_/buckets/BUCKET_NAME/objects/random.txt
```
where BUCKET_NAME is the name of the Cloud Storage 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 creation to start filtering events.

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

While Cloud Run does not charge when the service is not in use, you might still be charged for storing the container image in Artifact Registry, storing files in your Cloud Storage bucket, and Eventarc resources.

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