Traditionally, we have managed virtual machines individually. Instance groups let us manage a group of identical virtual machines as a single entity. These virtual machines are created from an instance template, like the one which we created in the previous tip. Now, if we have to make a change in instance configuration, that change would be applied to all the instances in the group.

Perhaps, the most important feature of an instance group is auto-scaling. In event of high resource requirements, the instance group can scale up to a predefined number automatically:

- name: create an instance group with autoscaling
  gce_mig:
    name: app-mig
    zone: "{{ zone }}"
   ...