Remediation

From Google Cloud Console

Create the prescribed log metric:

1. Go to Logging/Logs-based Metrics by visiting https://console.cloud.google.com/logs/metrics and click "CREATE METRIC".

2. Click the down arrow symbol on the Filter Bar at the rightmost corner and select Convert to Advanced Filter.

3. Clear any text and add:

   resource.type="gcs_bucket" 
   AND protoPayload.methodName="storage.setIamPermissions"

4. Click Submit Filter. Displayed logs appear based on the filter text entered by the user.

5. In the Metric Editor menu on the right, fill out the name field. Set Units to 1 (default) and Type to Counter. This ensures that the log metric counts the number of log entries matching the user's advanced logs query.

6. Click Create Metric.

Create the prescribed Alert Policy:

1. Identify the newly created metric under the section User-defined Metrics at https://console.cloud.google.com/logs/metrics.

2. Click the 3-dot icon in the rightmost column for the new metric and select Create alert from Metric. A new page appears.

3. Fill out the alert policy configuration and click Save. Choose the alerting threshold and configuration that makes sense for the user's organization. For example, a threshold of zero (0) for the most recent value ensures that a notification is triggered for every owner change in the project:

   Set `Aggregator` to `Count`
   Set `Configuration`:
   - Condition: above
   - Threshold: 0
   - For: most recent value

4. Configure the desired notification channels in the section Notifications.

5. Name the policy and click Save.

From Google Cloud CLI

Create the prescribed Log Metric:

• Use the command gcloud beta logging metrics create.

Create the prescribed alert policy:

• Use the command gcloud alpha monitoring policies create.