How to update all machines in an instance group on Google Cloud Platform?

Question

I have multiple machines managed by auto scaling in Google Compute Engine. I would like to redeploy all my machines (create new ones based on the same instance template and delete all the old ones). I do not want any service interruption.

How can I do that?

Answer 1

You can use the following gcloud command to recreate the existing VMs using the new or the same template whichever is set to your managed group:

$ gcloud compute instance-groups managed recreate-instances NAME --instances=INSTANCE

Answer 2

Rolling updates seems to be a nice solution: https://cloud.google.com/compute/docs/instance-groups/manager/#applying_rolling_updates_using_the_updater_service