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GCP Compute Instance Group Manager

A Compute Instance Group Manager (IGM) is the control plane object for a managed instance group on Google Cloud Platform. It maintains a specified number of identical virtual machine (VM) instances, applying a chosen instance template, performing rolling updates, auto-healing failed VMs and coordinating integrations such as autoscaling and load balancing. Full product documentation is available in the official Google Cloud guide: https://cloud.google.com/compute/docs/reference/rest/v1/instanceGroupManagers/get.

Terraform Mappings:

  • google_compute_instance_group_manager.name

Supported Methods​

  • GET: Get GCP Compute Instance Group Manager by "gcp-compute-instance-group-manager-name"
  • LIST: List all GCP Compute Instance Group Manager items
  • SEARCH

gcp-compute-instance-group​

An instance group resource is the data-plane object that contains the individual VMs. The Instance Group Manager is the controller that creates and manages this group, so every IGM will reference exactly one managed instance group.

gcp-compute-target-pool​

When an IGM is configured for network load balancing, it can attach the instances it manages to one or more Target Pools. The link represents this optional association.

gcp-compute-autoscaler​

Autoscalers use metrics such as CPU usage to resize a managed instance group. An Autoscaler resource references the Instance Group Manager it controls, creating a one-to-one relationship in most deployments.

gcp-compute-instance-template​

The IGM relies on an Instance Template to define the VM image, machine type, boot disk and metadata for the instances it creates. The template is immutable, so the manager stores a pointer to the template resource.