AWS Auto Scaling Group (ASG) Terraform module

Terraform module which creates Auto Scaling resources on AWS.

These types of resources are supported:

• Launch Configuration
• Auto Scaling Group

Terraform versions

Terraform 0.12. Pin module version to ~> v3.0. Submit pull-requests to master branch.

Usage

module "asg" {
  source  = "terraform-aws-modules/autoscaling/aws"
  version = "~> 3.0"
  
  name = "service"

  # Launch configuration
  lc_name = "example-lc"

  image_id        = "ami-ebd02392"
  instance_type   = "t2.micro"
  security_groups = ["sg-12345678"]

  ebs_block_device = [
    {
      device_name           = "/dev/xvdz"
      volume_type           = "gp2"
      volume_size           = "50"
      delete_on_termination = true
    },
  ]

  root_block_device = [
    {
      volume_size = "50"
      volume_type = "gp2"
    },
  ]

  # Auto scaling group
  asg_name                  = "example-asg"
  vpc_zone_identifier       = ["subnet-1235678", "subnet-87654321"]
  health_check_type         = "EC2"
  min_size                  = 0
  max_size                  = 1
  desired_capacity          = 1
  wait_for_capacity_timeout = 0

  tags = [
    {
      key                 = "Environment"
      value               = "dev"
      propagate_at_launch = true
    },
    {
      key                 = "Project"
      value               = "megasecret"
      propagate_at_launch = true
    },
  ]

  tags_as_map = {
    extra_tag1 = "extra_value1"
    extra_tag2 = "extra_value2"
  }
}

Conditional creation

Normally this module creates both Auto Scaling Group (ASG) and Launch Configuration (LC), and connect them together. It is possible to customize this behaviour passing different parameters to this module:

1. To create ASG, but not LC. Associate ASG with an existing LC:

create_lc = false
launch_configuration = "existing-launch-configuration"

1. To create LC, but not ASG. Outputs may produce errors.

create_asg = false

1. To create ASG with initial lifecycle hook

create_asg_with_initial_lifecycle_hook = true

initial_lifecycle_hook_name                  = "NameOfLifeCycleHook"
initial_lifecycle_hook_lifecycle_transition  = "autoscaling:EC2_INSTANCE_TERMINATING"
initial_lifecycle_hook_notification_metadata =<<EOF
{
  "foo": "bar"
}
EOF

1. To disable creation of both resources (LC and ASG) you can specify both arguments create_lc = false and create_asg = false. Sometimes you need to use this way to create resources in modules conditionally but Terraform does not allow to use count inside module block.

Tags

There are two ways to specify tags for auto-scaling group in this module - tags and tags_as_map. See examples/asg_ec2/main.tf for example.

Examples

• Auto Scaling Group without ELB
• Auto Scaling Group with ELB
• Auto Scaling Group with external Launch Configuration

Requirements

Providers

Modules

No Modules.

Resources

Inputs

[
  "GroupMinSize",
  "GroupMaxSize",
  "GroupDesiredCapacity",
  "GroupInServiceInstances",
  "GroupPendingInstances",
  "GroupStandbyInstances",
  "GroupTerminatingInstances",
  "GroupTotalInstances"
]

[
  "Default"
]

Outputs

Authors

Module managed by Anton Babenko.

Thanks to Jamie-BitFlight who added possibility to specify unlimited numbers of tags.

License

Apache 2 Licensed. See LICENSE for full details.