» google_compute_instance_group_manager

The Google Compute Engine Instance Group Manager API creates and manages pools of homogeneous Compute Engine virtual machine instances from a common instance template. For more information, see the official documentation and API

» Example Usage with top level instance template

resource "google_compute_health_check" "autohealing" {
  name                = "autohealing-health-check"
  check_interval_sec  = 5
  timeout_sec         = 5
  healthy_threshold   = 2
  unhealthy_threshold = 10                         # 50 seconds

  http_health_check {
    request_path = "/healthz"
    port         = "8080"
  }
}

resource "google_compute_instance_group_manager" "appserver" {
  name = "appserver-igm"

  base_instance_name = "app"
  instance_template  = "${google_compute_instance_template.appserver.self_link}"
  update_strategy    = "NONE"
  zone               = "us-central1-a"

  target_pools = ["${google_compute_target_pool.appserver.self_link}"]
  target_size  = 2

  named_port {
    name = "customHTTP"
    port = 8888
  }

  auto_healing_policies {
    health_check      = "${google_compute_health_check.autohealing.self_link}"
    initial_delay_sec = 300
  }
}

» Example Usage with multiple Versions

resource "google_compute_instance_group_manager" "appserver" {
  name = "appserver-igm"

  base_instance_name = "app"
  update_strategy    = "NONE"
  zone               = "us-central1-a"

  target_size  = 5

  version {
    instance_template  = "${google_compute_instance_template.appserver.self_link}"
  }

  version {
    instance_template  = "${google_compute_instance_template.appserver-canary.self_link}"
    target_size {
      fixed = 1
    }
  }
}

» Argument Reference

The following arguments are supported:

  • base_instance_name - (Required) The base instance name to use for instances in this group. The value must be a valid RFC1035 name. Supported characters are lowercase letters, numbers, and hyphens (-). Instances are named by appending a hyphen and a random four-character string to the base instance name.

  • instance_template - (Optional) The full URL to an instance template from which all new instances will be created. Conflicts with version (see documentation)

  • version - (Optional) Application versions managed by this instance group. Each version deals with a specific instance template, allowing canary release scenarios. Conflicts with instance_template. Structure is documented below. Beware that exactly one version must not specify a target size. It means that versions with a target size will respect the setting, and the one without target size will be applied to all remaining Instances (top level target_size - each version target_size). This property is in beta, and should be used with the terraform-provider-google-beta provider. See Provider Versions for more details on beta fields.

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

  • zone - (Required) The zone that instances in this group should be created in.


  • description - (Optional) An optional textual description of the instance group manager.

  • named_port - (Optional) The named port configuration. See the section below for details on configuration.

  • project - (Optional) The ID of the project in which the resource belongs. If it is not provided, the provider project is used.

  • update_strategy - (Optional, Default "REPLACE") If the instance_template resource is modified, a value of "NONE" will prevent any of the managed instances from being restarted by Terraform. A value of "REPLACE" will restart all of the instances at once. "ROLLING_UPDATE" is supported as a beta feature. A value of "ROLLING_UPDATE" requires rolling_update_policy block to be set

  • target_size - (Optional) The target number of running instances for this managed instance group. This value should always be explicitly set unless this resource is attached to an autoscaler, in which case it should never be set. Defaults to 0.

  • target_pools - (Optional) The full URL of all target pools to which new instances in the group are added. Updating the target pools attribute does not affect existing instances.

  • wait_for_instances - (Optional) Whether to wait for all instances to be created/updated before returning. Note that if this is set to true and the operation does not succeed, Terraform will continue trying until it times out.


  • auto_healing_policies - (Optional) The autohealing policies for this managed instance group. You can specify only one value. Structure is documented below. For more information, see the official documentation. This property is in beta, and should be used with the terraform-provider-google-beta provider. See Provider Versions for more details on beta fields.

  • rolling_update_policy - (Optional) The update policy for this managed instance group. Structure is documented below. For more information, see the official documentation and API This property is in beta, and should be used with the terraform-provider-google-beta provider. See Provider Versions for more details on beta fields.


The rolling_update_policy block supports:

rolling_update_policy{
  type = "PROACTIVE"
  minimal_action = "REPLACE"
  max_surge_percent = 20
  max_unavailable_fixed = 2
  min_ready_sec = 50
}
  • minimal_action - (Required) - Minimal action to be taken on an instance. Valid values are "RESTART", "REPLACE"

  • type - (Required) - The type of update. Valid values are "OPPORTUNISTIC", "PROACTIVE"

  • max_surge_fixed - (Optional), The maximum number of instances that can be created above the specified targetSize during the update process. Conflicts with max_surge_percent. If neither is set, defaults to 1

  • max_surge_percent - (Optional), The maximum number of instances(calculated as percentage) that can be created above the specified targetSize during the update process. Conflicts with max_surge_fixed.

  • max_unavailable_fixed - (Optional), The maximum number of instances that can be unavailable during the update process. Conflicts with max_unavailable_percent. If neither is set, defaults to 1

  • max_unavailable_percent - (Optional), The maximum number of instances(calculated as percentage) that can be unavailable during the update process. Conflicts with max_unavailable_fixed.

  • min_ready_sec - (Optional), Minimum number of seconds to wait for after a newly created instance becomes available. This value must be from range [0, 3600]


The named_port block supports: (Include a named_port block for each named-port required).

  • name - (Required) The name of the port.

  • port - (Required) The port number.


The auto_healing_policies block supports:

  • health_check - (Required) The health check resource that signals autohealing.

  • initial_delay_sec - (Required) The number of seconds that the managed instance group waits before it applies autohealing policies to new instances or recently recreated instances. Between 0 and 3600.

The version block supports:

version {
 name = "appserver-canary"
 instance_template = "${google_compute_instance_template.appserver-canary.self_link}"
 target_size {
   fixed = 1
 }
}
version {
 name = "appserver-canary"
 instance_template = "${google_compute_instance_template.appserver-canary.self_link}"
 target_size {
   percent = 20
 }
}
  • name - (Required) - Version name.

  • instance_template - (Required) - The full URL to an instance template from which all new instances of this version will be created.

  • target_size - (Optional) - The number of instances calculated as a fixed number or a percentage depending on the settings. Structure is documented below.

The target_size block supports:

  • fixed - (Optional), The number of instances which are managed for this version. Conflicts with percent.

  • percent - (Optional), The number of instances (calculated as percentage) which are managed for this version. Conflicts with fixed.

» Attributes Reference

In addition to the arguments listed above, the following computed attributes are exported:

  • fingerprint - The fingerprint of the instance group manager.

  • instance_group - The full URL of the instance group created by the manager.

  • self_link - The URL of the created resource.

» Import

Instance group managers can be imported using the name, e.g.

$ terraform import google_compute_instance_group_manager.appserver appserver-igm