Building Google Cloud Platform Solutions

Default and system users

When an instance is created for either type, they are provisioned with default user. For MySQL, the default user is 'root'@'%', meaning root can connect from any host. On PostgreSQL, the default user is postgres, which is functionally similar, though it lacks the SUPERUSER privilege.

When creating a new Cloud SQL instance, the default user's password may be provided or generated automatically. While the default password is not required, it should always be provided. Failure to provide a password for the default user represents a major security risk.

In addition to the default root user, MySQL instances are provisioned with two system users: cloudsqlimport@localhost and cloudsqlreplica@%. These users are used internally ...