Google Compute Engine Instance Group

google_compute_instance_group (Terraform)

The Instance Group in Compute Engine can be configured in Terraform with the resource name google_compute_instance_group. The following sections describe 2 examples of how to use the resource and its parameters.

Example Usage from GitHub

gashirar/gcs-malware-scanner-terraform

resource "google_compute_instance_group" "malware-scanner" {
  name        = "malware-scanner"
  description = "Malware Scan instance group"
  zone        = var.zone_1
  instances = [
    google_compute_instance.malware-scanner01.self_link,

aaronstrong/gcp-professional-architect

resource "google_compute_instance_group" "fw-umig-01" {
  name        = "firewall-umig-01"
  description = "Terraform unmanaged instance groups"
  zone        = "us-central1-b"
  network     = google_compute_network.public.id

Parameters

• description optional - string

An optional textual description of the instance group.

• id optional computed - string
• instances optional computed - set of string

List of instances in the group. They should be given as self_link URLs. When adding instances they must all be in the same network and zone as the instance group.

• name required - string

The name of the instance group. Must be 1-63 characters long and comply with RFC1035. Supported characters include lowercase letters, numbers, and hyphens.

• network optional computed - string

The URL of the network the instance group is in. If this is different from the network where the instances are in, the creation fails. Defaults to the network where the instances are in (if neither network nor instances is specified, this field will be blank).

• project optional computed - string

The ID of the project in which the resource belongs. If it is not provided, the provider project is used.

• self_link optional computed - string

The URI of the created resource.

• size optional computed - number

The number of instances in the group.

• zone optional computed - string

The zone that this instance group should be created in.

• named_port list block
  • name required - string

  The name which the port will be mapped to.

  • port required - number

  The port number to map the name to.

• timeouts single block
  • create optional - string
  • delete optional - string
  • update optional - string

Explanation in Terraform Registry

Creates a group of dissimilar Compute Engine virtual machine instances. For more information, see the official documentation and API -> Recreating an instance group that's in use by another resource will give a resourceInUseByAnotherResource error. You can avoid this error with a Terraform lifecycle block as outlined in the example below.

Tips: Best Practices for The Other Google Compute Engine Resources

In addition to the google_compute_disk, Google Compute Engine has the other resources that should be configured for security reasons. Please check some examples of those resources and precautions.

google_compute_disk

Ensure the encryption key for your GCE disk is stored securely

It is better to store the encryption key for your GCE disk securely. Secret Manager could be used instead.

google_compute_firewall

Ensure your VPC firewall blocks unwanted outbound traffic

It is better to block unwanted outbound traffic not to expose resources in the VPC to unwanted attacks.

google_compute_instance

Ensure appropriate service account is assigned to your GCE instance

It is better to create a custom service account for the instance and assign it.

google_compute_project_metadata

Ensure OS login for your GCE instances is enabled at project level

It is better to enable OS login for your GCE instances. Enabling OS login ensures that SSH keys used to connect to instances are mapped with IAM users, allowing centralized and automated SSH key management.

google_compute_ssl_policy

Ensure to use modern TLS protocols

It's better to adopt TLS v1.2+ instead of outdated TLS protocols.

google_compute_subnetwork

Ensure VPC flow logging is enabled

It is better to enable VPC flow logging. VPC flow logging allows us to audit traffic in your network.