Create a shutdown script named k99.shutdown in the /etc/rc.6.d/ directory

Create a shutdown script registered as a xinetd service in Linux and configure a Stackdriver endpoint check to call the service

Create a shutdown script and use it as the value for a new metadata entry with the key shutdown-script in the Cloud Platform Console when you create the new virtual machine instance

Create a shutdown script, registered as a xinetd service in Linux, and use the gcloud compute instances add-metadata command to specify the service URL as the value for a new metadata entry with the key shutdown-script-url