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layout	page_title	sidebar_current	description
aws	AWS: aws_autoscaling_group	docs-aws-resource-autoscaling-group	Provides an AutoScaling Group resource.

aws_autoscaling_group

Provides an AutoScaling Group resource.

Example Usage

resource "aws_autoscaling_group" "bar" {
  availability_zones = ["us-east-1a"]
  name = "foobar3-terraform-test"
  max_size = 5
  min_size = 2
  health_check_grace_period = 300
  health_check_type = "ELB"
  desired_capacity = 4
  force_delete = true
  launch_configuration = "${aws_launch_configuration.foobar.name}"

  tag {
    key = "foo"
    value = "bar"
    propagate_at_launch = true
  }
  tag {
    key = "lorem"
    value = "ipsum"
    propagate_at_launch = false
  }
}

Argument Reference

The following arguments are supported:

name - (Optional) The name of the auto scale group. By default generated by terraform.
max_size - (Required) The maximum size of the auto scale group.
min_size - (Required) The minimum size of the auto scale group. (See also Waiting for Capacity below.)
availability_zones - (Optional) A list of AZs to launch resources in. Required only if you do not specify any vpc_zone_identifier
launch_configuration - (Required) The name of the launch configuration to use.
health_check_grace_period - (Optional) Time after instance comes into service before checking health.
health_check_type - (Optional) "EC2" or "ELB". Controls how health checking is done.
desired_capacity - (Optional) The number of Amazon EC2 instances that should be running in the group. (See also Waiting for Capacity below.)
min_elb_capacity - (Optional) Setting this will cause Terraform to wait for this number of healthy instances all attached load balancers. (See also Waiting for Capacity below.)
force_delete - (Optional) Allows deleting the autoscaling group without waiting for all instances in the pool to terminate. You can force an autoscaling group to delete even if it's in the process of scaling a resource. Normally, Terraform drains all the instances before deleting the group. This bypasses that behavior and potentially leaves resources dangling.
load_balancers (Optional) A list of load balancer names to add to the autoscaling group names.
vpc_zone_identifier (Optional) A list of subnet IDs to launch resources in.
termination_policies (Optional) A list of policies to decide how the instances in the auto scale group should be terminated.
tag (Optional) A list of tag blocks. Tags documented below.
wait_for_capacity_timeout (Default: "10m") A maximum duration that Terraform should wait for ASG instances to be healthy before timing out. (See also Waiting for Capacity below.) Setting this to "0" causes Terraform to skip all Capacity Waiting behavior.

Tags support the following:

key - (Required) Key
value - (Required) Value
propagate_at_launch - (Required) Enables propagation of the tag to Amazon EC2 instances launched via this ASG

Attributes Reference

The following attributes are exported:

id - The autoscaling group name.
availability_zones - The availability zones of the autoscale group.
min_size - The minimum size of the autoscale group
max_size - The maximum size of the autoscale group
default_cooldown - Time between a scaling activity and the succeeding scaling activity.
name - The name of the autoscale group
health_check_grace_period - Time after instance comes into service before checking health.
health_check_type - "EC2" or "ELB". Controls how health checking is done.
desired_capacity -The number of Amazon EC2 instances that should be running in the group.
launch_configuration - The launch configuration of the autoscale group
vpc_zone_identifier - The VPC zone identifier
load_balancers (Optional) The load balancer names associated with the autoscaling group.

~> NOTE: When using ELB as the health_check_type, health_check_grace_period is required.

Waiting for Capacity

A newly-created ASG is initially empty and begins to scale to min_size (or desired_capacity, if specified) by launching instances using the provided Launch Configuration. These instances take time to launch and boot.

Terraform provides two mechanisms to help consistently manage ASG scale up time across dependent resources.

Waiting for ASG Capacity

The first is default behavior. Terraform waits after ASG creation for min_size (or desired_capacity, if specified) healthy instances to show up in the ASG before continuing.

Terraform considers an instance "healthy" when the ASG reports HealthStatus: "Healthy" and LifecycleState: "InService". See the AWS AutoScaling Docs for more information on an ASG's lifecycle.

Terraform will wait for healthy instances for up to wait_for_capacity_timeout. If ASG creation is taking more than a few minutes, it's worth investigating for scaling activity errors, which can be caused by problems with the selected Launch Configuration.

Setting wait_for_capacity_timeout to "0" disables ASG Capacity waiting.

Waiting for ELB Capacity

The second mechanism is optional, and affects ASGs with attached Load Balancers. If min_elb_capacity is set, Terraform will wait for that number of Instances to be "InService" in all attached load_balancers. This can be used to ensure that service is being provided before Terraform moves on.

As with ASG Capacity, Terraform will wait for up to wait_for_capacity_timeout (for "InService" instances. If ASG creation takes more than a few minutes, this could indicate one of a number of configuration problems. See the AWS Docs on Load Balancer Troubleshooting for more information.

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