title: Rolling Update Of docker containers in GCP Instance Group
body: <p>I am deploying a Java Spring Boot container inside a VM in a instance group in GCP.
  So each VM will have one Spring Boot container.
  I am looking to achieve a rolling update of the containers.</p>
  <ul>
  <li>I can use docker compose to remove the latest container, pull the image (from a docker registry) and then recreate the container.</li>
  <li>But the containers are in different VMs under a single instance group in GCP, how do I do a rolling update across VMs?</li>
  <li>I am using unmanaged instance group where each VM is having the docker container of the spring boot application running in it.</li>
  </ul>