Last week, a company deployed a new App Engine application that writes logs to BigQuery.

To validate that all data written to BigQuery was done using the App Engine Default Service Account, you can use StackDriver Logging (now known as Cloud Logging) to filter and inspect the logs for BigQuery insert jobs. By hiding the entries matching the App Engine Default Service Account, you can ensure that no other service account has written to BigQuery if the resulting list is empty.

Steps:

Open Cloud Logging: Navigate to Cloud Logging in the Google Cloud Console.

Filter Logs: Apply a filter to display logs for BigQuery insert jobs.

Inspect Entries: Click on the email address that corresponds to the App Engine Default Service Account in the authentication field.

Hide Matching Entries: Select the option to hide matching entries.

Validate: Check if the resulting list is empty, confirming that no other service account has performed write operations to BigQuery.