# AWS Auto Scaling Group (ASG) Terraform module Terraform module which creates Auto Scaling resources on AWS. [![SWUbanner](https://raw.githubusercontent.com/vshymanskyy/StandWithUkraine/main/banner2-direct.svg)](https://github.com/vshymanskyy/StandWithUkraine/blob/main/docs/README.md) ## Available Features - Autoscaling group with launch template - either created by the module or utilizing an existing launch template - Autoscaling group utilizing mixed instances policy - Ability to configure autoscaling groups to set instance refresh configuration and add lifecycle hooks - Ability to create an autoscaling group that respects `desired_capacity` or one that ignores to allow for scaling without conflicting Terraform diffs - IAM role and instance profile creation ## Usage ```hcl module "asg" { source = "terraform-aws-modules/autoscaling/aws" # Autoscaling group name = "example-asg" min_size = 0 max_size = 1 desired_capacity = 1 wait_for_capacity_timeout = 0 health_check_type = "EC2" vpc_zone_identifier = ["subnet-1235678", "subnet-87654321"] initial_lifecycle_hooks = [ { name = "ExampleStartupLifeCycleHook" default_result = "CONTINUE" heartbeat_timeout = 60 lifecycle_transition = "autoscaling:EC2_INSTANCE_LAUNCHING" notification_metadata = jsonencode({ "hello" = "world" }) }, { name = "ExampleTerminationLifeCycleHook" default_result = "CONTINUE" heartbeat_timeout = 180 lifecycle_transition = "autoscaling:EC2_INSTANCE_TERMINATING" notification_metadata = jsonencode({ "goodbye" = "world" }) } ] instance_refresh = { strategy = "Rolling" preferences = { checkpoint_delay = 600 checkpoint_percentages = [35, 70, 100] instance_warmup = 300 min_healthy_percentage = 50 max_healthy_percentage = 100 } triggers = ["tag"] } # Launch template launch_template_name = "example-asg" launch_template_description = "Launch template example" update_default_version = true image_id = "ami-ebd02392" instance_type = "t3.micro" ebs_optimized = true enable_monitoring = true # IAM role & instance profile create_iam_instance_profile = true iam_role_name = "example-asg" iam_role_path = "/ec2/" iam_role_description = "IAM role example" iam_role_tags = { CustomIamRole = "Yes" } iam_role_policies = { AmazonSSMManagedInstanceCore = "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore" } block_device_mappings = [ { # Root volume device_name = "/dev/xvda" no_device = 0 ebs = { delete_on_termination = true encrypted = true volume_size = 20 volume_type = "gp2" } }, { device_name = "/dev/sda1" no_device = 1 ebs = { delete_on_termination = true encrypted = true volume_size = 30 volume_type = "gp2" } } ] capacity_reservation_specification = { capacity_reservation_preference = "open" } cpu_options = { core_count = 1 threads_per_core = 1 } credit_specification = { cpu_credits = "standard" } instance_market_options = { market_type = "spot" spot_options = { block_duration_minutes = 60 } } # This will ensure imdsv2 is enabled, required, and a single hop which is aws security # best practices # See https://docs.aws.amazon.com/securityhub/latest/userguide/autoscaling-controls.html#autoscaling-4 metadata_options = { http_endpoint = "enabled" http_tokens = "required" http_put_response_hop_limit = 1 } network_interfaces = [ { delete_on_termination = true description = "eth0" device_index = 0 security_groups = ["sg-12345678"] }, { delete_on_termination = true description = "eth1" device_index = 1 security_groups = ["sg-12345678"] } ] placement = { availability_zone = "us-west-1b" } tag_specifications = [ { resource_type = "instance" tags = { WhatAmI = "Instance" } }, { resource_type = "volume" tags = { WhatAmI = "Volume" } }, { resource_type = "spot-instances-request" tags = { WhatAmI = "SpotInstanceRequest" } } ] tags = { Environment = "dev" Project = "megasecret" } } ``` ## Conditional creation The following combinations are supported to conditionally create resources and/or use externally created resources within the module: Note: the default behavior of the module is to create an autoscaling group and launch template. - Disable resource creation (no resources created): ```hcl create = false create_launch_template = false ``` - Create only a launch template: ```hcl create = false ``` - Create an autoscaling group using an externally created launch template: ```hcl create_launch_template = false launch_template = aws_launch_template.my_launch_template.name ``` - Create an autoscaling group with a mixed instance policy: ```hcl use_mixed_instances_policy = true ``` - Create the autoscaling policies: ```hcl scaling_policies = { my-policy = { policy_type = "TargetTrackingScaling" target_tracking_configuration = { predefined_metric_specification = { predefined_metric_type = "ASGAverageCPUUtilization" resource_label = "MyLabel" } target_value = 50.0 } } } ``` ## Known limitations (Terraform/OpenTofu, not this module) A few requests come up again and again and cannot be implemented by this module, or by any module: Terraform requires `lifecycle` arguments to be literal values inside the resource block. [hashicorp/terraform#18367](https://github.com/hashicorp/terraform/issues/18367) has been open since 2018, [#22544](https://github.com/hashicorp/terraform/issues/22544) since 2019, and [opentofu/opentofu#1329](https://github.com/opentofu/opentofu/issues/1329) is the same request for OpenTofu. - **Auto Scaling group desired_capacity reverts on every apply** - Native options: leave `desired_capacity` unset, or fork and add `ignore_changes = [desired_capacity]`. [Compliance.tf](https://compliance.tf/?utm_source=github&utm_medium=readme&utm_campaign=known-limitations) serves this module with these rules applied at download time, on top of whatever your organization already has enabled there. Inputs and outputs do not change; the `source` line does. Drop the `version` argument and pin the release you use by adding `&version=` and that release number to the URL. To get started, register a free compliance.tf account and configure an access token: source = "https://registry.compliance.tf/terraform-aws-modules/autoscaling/aws?add_rules=lifecycle_ignore_scaling_changes" The full workaround for each item above, and the exact diff each rule makes, are in the [compliance.tf docs for this module](https://compliance.tf/docs/workarounds/terraform-aws-autoscaling/?utm_source=github&utm_medium=readme&utm_campaign=known-limitations). To preview a diff without an account, open this module in the [Rules Playground](https://registry.compliance.tf/playground?module=terraform-aws-modules/autoscaling/aws&rules=lifecycle_ignore_scaling_changes). Disclosure: written by this module's maintainer, who also builds [compliance.tf](https://compliance.tf/?utm_source=github&utm_medium=readme&utm_campaign=known-limitations). ## Examples - [Complete](https://github.com/terraform-aws-modules/terraform-aws-autoscaling/tree/master/examples/complete) - Creates several variations of resources for autoscaling groups and launch templates. ## Requirements | Name | Version | | ---- | ------- | | [terraform](#requirement\_terraform) | >= 1.5.7 | | [aws](#requirement\_aws) | >= 6.56 | ## Providers | Name | Version | | ---- | ------- | | [aws](#provider\_aws) | >= 6.56 | ## Modules No modules. ## Resources | Name | Type | | ---- | ---- | | [aws_autoscaling_group.idc](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_group) | resource | | [aws_autoscaling_group.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_group) | resource | | [aws_autoscaling_policy.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_policy) | resource | | [aws_autoscaling_schedule.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_schedule) | resource | | [aws_autoscaling_traffic_source_attachment.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_traffic_source_attachment) | resource | | [aws_iam_instance_profile.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_instance_profile) | resource | | [aws_iam_role.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role) | resource | | [aws_iam_role_policy_attachment.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource | | [aws_launch_template.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/launch_template) | resource | | [aws_iam_policy_document.assume_role_policy](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source | | [aws_partition.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/partition) | data source | ## Inputs | Name | Description | Type | Default | Required | | ---- | ----------- | ---- | ------- | :------: | | [autoscaling\_group\_tags](#input\_autoscaling\_group\_tags) | A map of additional tags to add to the autoscaling group | `map(string)` | `{}` | no | | [autoscaling\_group\_tags\_not\_propagate\_at\_launch](#input\_autoscaling\_group\_tags\_not\_propagate\_at\_launch) | A list of tag keys that should NOT be propagated to launched EC2 instances | `list(string)` | `[]` | no | | [availability\_zone\_distribution](#input\_availability\_zone\_distribution) | A map of configuration for capacity distribution across availability zones |

object({
    capacity_distribution_strategy = optional(string)
  })

| `null` | no | | [availability\_zones](#input\_availability\_zones) | A list of Availability Zones where instances in the Auto Scaling group can be created. Used for launching into the default VPC subnet in each Availability Zone when not using the `vpc_zone_identifier` attribute, or for attaching a network interface when an existing network interface ID is specified in a launch template. Conflicts with `vpc_zone_identifier` | `list(string)` | `null` | no | | [block\_device\_mappings](#input\_block\_device\_mappings) | Specify volumes to attach to the instance besides the volumes specified by the AMI |

list(object({
    device_name = optional(string)
    ebs = optional(object({
      delete_on_termination      = optional(bool)
      encrypted                  = optional(bool)
      iops                       = optional(number)
      kms_key_id                 = optional(string)
      snapshot_id                = optional(string)
      throughput                 = optional(number)
      volume_initialization_rate = optional(number)
      volume_size                = optional(number)
      volume_type                = optional(string)
    }))
    no_device    = optional(string)
    virtual_name = optional(string)
  }))

object({
    capacity_reservation_preference = optional(string)
    capacity_reservation_target = optional(object({
      capacity_reservation_id                 = optional(string)
      capacity_reservation_resource_group_arn = optional(string)
    }))
  })

object({
    amd_sev_snp           = optional(string)
    core_count            = optional(number)
    nested_virtualization = optional(string)
    threads_per_core      = optional(number)
  })

object({
    cpu_credits = optional(string)
  })

object({
    enabled = optional(bool)
  })

object({
    configured = optional(bool)
  })

| `null` | no | | [iam\_instance\_profile\_arn](#input\_iam\_instance\_profile\_arn) | Amazon Resource Name (ARN) of an existing IAM instance profile. Used when `create_iam_instance_profile` = `false` | `string` | `null` | no | | [iam\_instance\_profile\_name](#input\_iam\_instance\_profile\_name) | The name of the IAM instance profile to be created (`create_iam_instance_profile` = `true`) or existing (`create_iam_instance_profile` = `false`) | `string` | `null` | no | | [iam\_role\_description](#input\_iam\_role\_description) | Description of the role | `string` | `null` | no | | [iam\_role\_name](#input\_iam\_role\_name) | Name to use on IAM role created | `string` | `null` | no | | [iam\_role\_path](#input\_iam\_role\_path) | IAM role path | `string` | `null` | no | | [iam\_role\_permissions\_boundary](#input\_iam\_role\_permissions\_boundary) | ARN of the policy that is used to set the permissions boundary for the IAM role | `string` | `null` | no | | [iam\_role\_policies](#input\_iam\_role\_policies) | IAM policies to attach to the IAM role | `map(string)` | `{}` | no | | [iam\_role\_tags](#input\_iam\_role\_tags) | A map of additional tags to add to the IAM role created | `map(string)` | `{}` | no | | [iam\_role\_use\_name\_prefix](#input\_iam\_role\_use\_name\_prefix) | Determines whether the IAM role name (`iam_role_name`) is used as a prefix | `bool` | `true` | no | | [ignore\_desired\_capacity\_changes](#input\_ignore\_desired\_capacity\_changes) | Determines whether the `desired_capacity` value is ignored after initial apply. See README note for more details | `bool` | `false` | no | | [ignore\_failed\_scaling\_activities](#input\_ignore\_failed\_scaling\_activities) | Whether to ignore failed Auto Scaling scaling activities while waiting for capacity. The default is false -- failed scaling activities cause errors to be returned. | `bool` | `false` | no | | [image\_id](#input\_image\_id) | The AMI from which to launch the instance | `string` | `null` | no | | [initial\_lifecycle\_hooks](#input\_initial\_lifecycle\_hooks) | One or more Lifecycle Hooks to attach to the Auto Scaling Group before instances are launched. The syntax is exactly the same as the separate `aws_autoscaling_lifecycle_hook` resource, without the `autoscaling_group_name` attribute. Please note that this will only work when creating a new Auto Scaling Group. For all other use-cases, please use `aws_autoscaling_lifecycle_hook` resource |

list(object({
    default_result          = optional(string)
    heartbeat_timeout       = optional(number)
    lifecycle_transition    = string
    name                    = string
    notification_metadata   = optional(string)
    notification_target_arn = optional(string)
    role_arn                = optional(string)
  }))

object({
    retention_triggers = optional(object({
      terminate_hook_abandon = optional(string)
    }))
  })

| `null` | no | | [instance\_maintenance\_policy](#input\_instance\_maintenance\_policy) | If this block is configured, add a instance maintenance policy to the specified Auto Scaling group |

object({
    max_healthy_percentage = number
    min_healthy_percentage = number
  })

object({
    market_type = optional(string)
    spot_options = optional(object({
      block_duration_minutes         = optional(number)
      instance_interruption_behavior = optional(string)
      max_price                      = optional(string)
      spot_instance_type             = optional(string)
      valid_until                    = optional(string)
    }))
  })

object({
    preferences = optional(object({
      alarm_specification = optional(object({
        alarms = optional(list(string))
      }))
      auto_rollback                = optional(bool)
      checkpoint_delay             = optional(number)
      checkpoint_percentages       = optional(list(number))
      instance_warmup              = optional(number)
      max_healthy_percentage       = optional(number)
      min_healthy_percentage       = optional(number)
      scale_in_protected_instances = optional(string)
      skip_matching                = optional(bool)
      standby_instances            = optional(string)
    }))
    strategy = string
    triggers = optional(list(string))
  })

| `null` | no | | [instance\_requirements](#input\_instance\_requirements) | The attribute requirements for the type of instance. If present then `instance_type` cannot be present |

object({
    accelerator_count = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    accelerator_manufacturers = optional(list(string))
    accelerator_names         = optional(list(string))
    accelerator_total_memory_mib = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    accelerator_types      = optional(list(string))
    allowed_instance_types = optional(list(string))
    bare_metal             = optional(string)
    baseline_ebs_bandwidth_mbps = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    burstable_performance                                   = optional(string)
    cpu_manufacturers                                       = optional(list(string))
    excluded_instance_types                                 = optional(list(string))
    instance_generations                                    = optional(list(string))
    local_storage                                           = optional(string)
    local_storage_types                                     = optional(list(string))
    max_spot_price_as_percentage_of_optimal_on_demand_price = optional(number)
    memory_gib_per_vcpu = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    memory_mib = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    network_bandwidth_gbps = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    network_interface_count = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    on_demand_max_price_percentage_over_lowest_price = optional(number)
    require_hibernate_support                        = optional(bool)
    spot_max_price_percentage_over_lowest_price      = optional(number)
    total_local_storage_gb = optional(object({
      max = optional(number)
      min = optional(number)
    }))
    vcpu_count = optional(object({
      max = optional(number)
      min = optional(number)
    }))
  })

| `null` | no | | [instance\_type](#input\_instance\_type) | The type of the instance. If present then `instance_requirements` cannot be present | `string` | `null` | no | | [kernel\_id](#input\_kernel\_id) | The kernel ID | `string` | `null` | no | | [key\_name](#input\_key\_name) | The key name that should be used for the instance | `string` | `null` | no | | [launch\_template\_description](#input\_launch\_template\_description) | Description of the launch template | `string` | `null` | no | | [launch\_template\_id](#input\_launch\_template\_id) | ID of an existing launch template to be used (created outside of this module) | `string` | `null` | no | | [launch\_template\_name](#input\_launch\_template\_name) | Name of launch template to be created | `string` | `""` | no | | [launch\_template\_tags](#input\_launch\_template\_tags) | A map of additional tags to add to the launch template | `map(string)` | `{}` | no | | [launch\_template\_use\_name\_prefix](#input\_launch\_template\_use\_name\_prefix) | Determines whether to use `launch_template_name` as is or create a unique name beginning with the `launch_template_name` as the prefix | `bool` | `true` | no | | [launch\_template\_version](#input\_launch\_template\_version) | Launch template version. Can be version number, `$Latest`, or `$Default` | `string` | `null` | no | | [license\_specifications](#input\_license\_specifications) | A list of license specifications to associate with |

list(object({
    license_configuration_arn = string
  }))

object({
    auto_recovery = optional(string)
  })

object({
    http_endpoint               = optional(string, "enabled")
    http_protocol_ipv6          = optional(string)
    http_put_response_hop_limit = optional(number, 1)
    http_tokens                 = optional(string, "required")
    instance_metadata_tags      = optional(string)
  })

{
  "http_endpoint": "enabled",
  "http_put_response_hop_limit": 1,
  "http_tokens": "required"
}

object({
    instances_distribution = optional(object({
      on_demand_allocation_strategy            = optional(string)
      on_demand_base_capacity                  = optional(number)
      on_demand_percentage_above_base_capacity = optional(number)
      spot_allocation_strategy                 = optional(string)
      spot_instance_pools                      = optional(number)
      spot_max_price                           = optional(string)
    }))
    launch_template = object({
      override = optional(list(object({
        instance_requirements = optional(object({
          accelerator_count = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          accelerator_manufacturers = optional(list(string))
          accelerator_names         = optional(list(string))
          accelerator_total_memory_mib = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          accelerator_types      = optional(list(string))
          allowed_instance_types = optional(list(string))
          bare_metal             = optional(string)
          baseline_ebs_bandwidth_mbps = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          burstable_performance                                   = optional(string)
          cpu_manufacturers                                       = optional(list(string))
          excluded_instance_types                                 = optional(list(string))
          instance_generations                                    = optional(list(string))
          local_storage                                           = optional(string)
          local_storage_types                                     = optional(list(string))
          max_spot_price_as_percentage_of_optimal_on_demand_price = optional(number)
          memory_gib_per_vcpu = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          memory_mib = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          network_bandwidth_gbps = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          network_interface_count = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          on_demand_max_price_percentage_over_lowest_price = optional(number)
          require_hibernate_support                        = optional(bool)
          spot_max_price_percentage_over_lowest_price      = optional(number)
          total_local_storage_gb = optional(object({
            max = optional(number)
            min = optional(number)
          }))
          vcpu_count = optional(object({
            max = optional(number)
            min = optional(number)
          }))
        }))
        instance_type = optional(string)
        launch_template_specification = optional(object({
          launch_template_id   = optional(string)
          launch_template_name = optional(string)
          version              = optional(string)
        }))
        weighted_capacity = optional(string)
      })))
    })
  })

list(object({
    associate_carrier_ip_address = optional(bool)
    associate_public_ip_address  = optional(bool)
    connection_tracking_specification = optional(object({
      tcp_established_timeout = optional(number)
      udp_stream_timeout      = optional(number)
      udp_timeout             = optional(number)
    }))
    delete_on_termination = optional(bool)
    description           = optional(string)
    device_index          = optional(number)
    ena_srd_specification = optional(object({
      ena_srd_enabled = optional(bool)
      ena_srd_udp_specification = optional(object({
        ena_srd_udp_enabled = optional(bool)
      }))
    }))
    interface_type       = optional(string)
    ipv4_address_count   = optional(number)
    ipv4_addresses       = optional(list(string))
    ipv4_prefix_count    = optional(number)
    ipv4_prefixes        = optional(list(string))
    ipv6_address_count   = optional(number)
    ipv6_addresses       = optional(list(string))
    ipv6_prefix_count    = optional(number)
    ipv6_prefixes        = optional(list(string))
    network_card_index   = optional(number)
    network_interface_id = optional(string)
    primary_ipv6         = optional(bool)
    private_ip_address   = optional(string)
    security_groups      = optional(list(string), [])
    subnet_id            = optional(string)
  }))

object({
    bandwidth_weighting = optional(string)
  })

object({
    affinity                = optional(string)
    availability_zone       = optional(string)
    group_id                = optional(string)
    group_name              = optional(string)
    host_id                 = optional(string)
    host_resource_group_arn = optional(string)
    partition_number        = optional(number)
    spread_domain           = optional(string)
    tenancy                 = optional(string)
  })

object({
    enable_resource_name_dns_aaaa_record = optional(bool)
    enable_resource_name_dns_a_record    = optional(bool)
    hostname_type                        = optional(string)
  })

map(object({
    adjustment_type           = optional(string)
    cooldown                  = optional(number)
    enabled                   = optional(bool)
    estimated_instance_warmup = optional(number)
    metric_aggregation_type   = optional(string)
    min_adjustment_magnitude  = optional(number)
    name                      = optional(string) # Will fall back to the map key if not provided
    policy_type               = optional(string)
    predictive_scaling_configuration = optional(object({
      max_capacity_breach_behavior = optional(string)
      max_capacity_buffer          = optional(number)
      metric_specification = object({
        customized_capacity_metric_specification = optional(object({
          metric_data_queries = optional(list(object({
            expression = optional(string)
            id         = string
            label      = optional(string)
            metric_stat = optional(object({
              metric = object({
                dimensions = optional(list(object({
                  name  = string
                  value = string
                })))
                metric_name = string
                namespace   = string
              })
              stat = string
              unit = optional(string)
            }))
            return_data = optional(bool)
          })))
        }))
        customized_load_metric_specification = optional(object({
          metric_data_queries = optional(list(object({
            expression = optional(string)
            id         = string
            label      = optional(string)
            metric_stat = optional(object({
              metric = object({
                dimensions = optional(list(object({
                  name  = string
                  value = string
                })))
                metric_name = string
                namespace   = string
              })
              stat = string
              unit = optional(string)
            }))
            return_data = optional(bool)
          })))
        }))
        customized_scaling_metric_specification = optional(object({
          metric_data_queries = optional(list(object({
            expression = optional(string)
            id         = string
            label      = optional(string)
            metric_stat = optional(object({
              metric = object({
                dimensions = optional(list(object({
                  name  = string
                  value = string
                })))
                metric_name = string
                namespace   = string
              })
              stat = string
              unit = optional(string)
            }))
            return_data = optional(bool)
          })))
        }))
        predefined_load_metric_specification = optional(object({
          predefined_metric_type = string
          resource_label         = optional(string)
        }))
        predefined_metric_pair_specification = optional(object({
          predefined_metric_type = string
          resource_label         = optional(string)
        }))
        predefined_scaling_metric_specification = optional(object({
          predefined_metric_type = string
          resource_label         = optional(string)
        }))
        target_value = optional(number)
      })
      mode                   = optional(string)
      scheduling_buffer_time = optional(number)
    }))
    scaling_adjustment = optional(number)
    step_adjustment = optional(list(object({
      metric_interval_lower_bound = optional(number)
      metric_interval_upper_bound = optional(number)
      scaling_adjustment          = number
    })))
    target_tracking_configuration = optional(object({
      customized_metric_specification = optional(object({
        metric_dimension = optional(list(object({
          name  = string
          value = string
        })))
        metric_name = optional(string)
        metrics = optional(list(object({
          expression = optional(string)
          id         = string
          label      = optional(string)
          metric_stat = optional(object({
            metric = object({
              dimensions = optional(list(object({
                name  = string
                value = string
              })))
              metric_name = string
              namespace   = string
            })
            period = optional(number)
            stat   = string
            unit   = optional(string)
          }))
          return_data = optional(bool)
        })))
        namespace = optional(string)
        period    = optional(number)
        statistic = optional(string)
        unit      = optional(string)
      }))
      disable_scale_in = optional(bool)
      predefined_metric_specification = optional(object({
        predefined_metric_type = string
        resource_label         = optional(string)
      }))
      target_value = number
    }))
  }))

map(object({
    desired_capacity = optional(number)
    end_time         = optional(string)
    max_size         = optional(number)
    min_size         = optional(number)
    recurrence       = optional(string)
    start_time       = optional(string)
    time_zone        = optional(string)
  }))

list(object({
    delete_on_termination    = optional(bool)
    device_index             = optional(number)
    interface_type           = optional(string)
    network_card_index       = optional(number)
    private_ip_address_count = optional(number)
    private_ip_addresses     = optional(list(string))
    secondary_subnet_id      = optional(string)
  }))

| `null` | no | | [security\_groups](#input\_security\_groups) | A list of security group IDs to associate | `list(string)` | `[]` | no | | [service\_linked\_role\_arn](#input\_service\_linked\_role\_arn) | The ARN of the service-linked role that the ASG will use to call other AWS services | `string` | `null` | no | | [suspended\_processes](#input\_suspended\_processes) | A list of processes to suspend for the Auto Scaling Group. The allowed values are `Launch`, `Terminate`, `HealthCheck`, `ReplaceUnhealthy`, `AZRebalance`, `AlarmNotification`, `ScheduledActions`, `AddToLoadBalancer`, `InstanceRefresh`. Note that if you suspend either the `Launch` or `Terminate` process types, it can prevent your Auto Scaling Group from functioning properly | `list(string)` | `[]` | no | | [tag\_specifications](#input\_tag\_specifications) | The tags to apply to the resources during launch |

list(object({
    resource_type = optional(string)
    tags          = optional(map(string), {})
  }))

| `null` | no | | [tags](#input\_tags) | A map of tags to assign to resources | `map(string)` | `{}` | no | | [termination\_policies](#input\_termination\_policies) | A list of policies to decide how the instances in the Auto Scaling Group should be terminated. The allowed values are `OldestInstance`, `NewestInstance`, `OldestLaunchConfiguration`, `ClosestToNextInstanceHour`, `OldestLaunchTemplate`, `AllocationStrategy`, `Default` | `list(string)` | `[]` | no | | [timeouts](#input\_timeouts) | Timeout configurations for the autoscaling group |

object({
    delete = optional(string)
  })

map(object({
    traffic_source_identifier = string
    traffic_source_type       = optional(string, "elbv2")
  }))

object({
    instance_reuse_policy = optional(object({
      reuse_on_scale_in = optional(bool)
    }))
    max_group_prepared_capacity = optional(number)
    min_size                    = optional(number)
    pool_state                  = optional(string)
  })

| `null` | no | ## Outputs | Name | Description | | ---- | ----------- | | [autoscaling\_group\_arn](#output\_autoscaling\_group\_arn) | The ARN for this AutoScaling Group | | [autoscaling\_group\_availability\_zones](#output\_autoscaling\_group\_availability\_zones) | The availability zones of the autoscale group | | [autoscaling\_group\_default\_cooldown](#output\_autoscaling\_group\_default\_cooldown) | Time between a scaling activity and the succeeding scaling activity | | [autoscaling\_group\_desired\_capacity](#output\_autoscaling\_group\_desired\_capacity) | The number of Amazon EC2 instances that should be running in the group | | [autoscaling\_group\_enabled\_metrics](#output\_autoscaling\_group\_enabled\_metrics) | List of metrics enabled for collection | | [autoscaling\_group\_health\_check\_grace\_period](#output\_autoscaling\_group\_health\_check\_grace\_period) | Time after instance comes into service before checking health | | [autoscaling\_group\_health\_check\_type](#output\_autoscaling\_group\_health\_check\_type) | EC2 or ELB. Controls how health checking is done | | [autoscaling\_group\_id](#output\_autoscaling\_group\_id) | The autoscaling group id | | [autoscaling\_group\_load\_balancers](#output\_autoscaling\_group\_load\_balancers) | The load balancer names associated with the autoscaling group | | [autoscaling\_group\_max\_size](#output\_autoscaling\_group\_max\_size) | The maximum size of the autoscale group | | [autoscaling\_group\_min\_size](#output\_autoscaling\_group\_min\_size) | The minimum size of the autoscale group | | [autoscaling\_group\_name](#output\_autoscaling\_group\_name) | The autoscaling group name | | [autoscaling\_group\_target\_group\_arns](#output\_autoscaling\_group\_target\_group\_arns) | List of Target Group ARNs that apply to this AutoScaling Group | | [autoscaling\_group\_vpc\_zone\_identifier](#output\_autoscaling\_group\_vpc\_zone\_identifier) | The VPC zone identifier | | [autoscaling\_policy\_arns](#output\_autoscaling\_policy\_arns) | ARNs of autoscaling policies | | [autoscaling\_schedule\_arns](#output\_autoscaling\_schedule\_arns) | ARNs of autoscaling group schedules | | [iam\_instance\_profile\_arn](#output\_iam\_instance\_profile\_arn) | ARN assigned by AWS to the instance profile | | [iam\_instance\_profile\_id](#output\_iam\_instance\_profile\_id) | Instance profile's ID | | [iam\_instance\_profile\_unique](#output\_iam\_instance\_profile\_unique) | Stable and unique string identifying the IAM instance profile | | [iam\_role\_arn](#output\_iam\_role\_arn) | The Amazon Resource Name (ARN) specifying the IAM role | | [iam\_role\_name](#output\_iam\_role\_name) | The name of the IAM role | | [iam\_role\_unique\_id](#output\_iam\_role\_unique\_id) | Stable and unique string identifying the IAM role | | [launch\_template\_arn](#output\_launch\_template\_arn) | The ARN of the launch template | | [launch\_template\_default\_version](#output\_launch\_template\_default\_version) | The default version of the launch template | | [launch\_template\_id](#output\_launch\_template\_id) | The ID of the launch template | | [launch\_template\_latest\_version](#output\_launch\_template\_latest\_version) | The latest version of the launch template | | [launch\_template\_name](#output\_launch\_template\_name) | The name of the launch template | ## Notes - A refresh will not start if `launch_template_version` is set to `$Latest` when using an external launch template. To trigger the refresh when the external launch template is changed, set this to `latest_version` of that `aws_launch_template resource`. ## Authors Module is maintained by [Anton Babenko](https://github.com/antonbabenko) with help from [these awesome contributors](https://github.com/terraform-aws-modules/terraform-aws-autoscaling/graphs/contributors). ## License Apache 2 Licensed. See [LICENSE](https://github.com/terraform-aws-modules/terraform-aws-autoscaling/tree/master/LICENSE) for full details. ## Additional information for users from Russia and Belarus * Russia has [illegally annexed Crimea in 2014](https://en.wikipedia.org/wiki/Annexation_of_Crimea_by_the_Russian_Federation) and [brought the war in Donbas](https://en.wikipedia.org/wiki/War_in_Donbas) followed by [full-scale invasion of Ukraine in 2022](https://en.wikipedia.org/wiki/2022_Russian_invasion_of_Ukraine). * Russia has brought sorrow and devastations to millions of Ukrainians, killed hundreds of innocent people, damaged thousands of buildings, and forced several million people to flee. * [Putin khuylo!](https://en.wikipedia.org/wiki/Putin_khuylo!)

AWS Auto Scaling Group (ASG) Terraform module

Terraform Module Source