AutoScalingGroupProps

class aws_cdk.aws_autoscaling.AutoScalingGroupProps(*, allow_all_outbound=None, associate_public_ip_address=None, auto_scaling_group_name=None, block_devices=None, capacity_rebalance=None, cooldown=None, default_instance_warmup=None, desired_capacity=None, group_metrics=None, health_check=None, ignore_unmodified_size_properties=None, instance_monitoring=None, key_name=None, key_pair=None, max_capacity=None, max_instance_lifetime=None, min_capacity=None, new_instances_protected_from_scale_in=None, notifications=None, signals=None, spot_price=None, ssm_session_permissions=None, termination_policies=None, termination_policy_custom_lambda_function_arn=None, update_policy=None, vpc_subnets=None, vpc, init=None, init_options=None, instance_type=None, launch_template=None, machine_image=None, max_healthy_percentage=None, min_healthy_percentage=None, mixed_instances_policy=None, require_imdsv2=None, role=None, security_group=None, user_data=None)

Bases: CommonAutoScalingGroupProps

Properties of a Fleet.

Parameters:

allow_all_outbound (Optional[bool]) – Whether the instances can initiate connections to anywhere by default. Default: true
associate_public_ip_address (Optional[bool]) – Whether instances in the Auto Scaling Group should have public IP addresses associated with them. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - Use subnet setting.
auto_scaling_group_name (Optional[str]) – The name of the Auto Scaling group. This name must be unique per Region per account. Default: - Auto generated by CloudFormation
block_devices (Optional[Sequence[Union[BlockDevice, Dict[str, Any]]]]) – Specifies how block devices are exposed to the instance. You can specify virtual devices and EBS volumes. Each instance that is launched has an associated root device volume, either an Amazon EBS volume or an instance store volume. You can use block device mappings to specify additional EBS volumes or instance store volumes to attach to an instance when it is launched. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - Uses the block device mapping of the AMI
capacity_rebalance (Optional[bool]) – Indicates whether Capacity Rebalancing is enabled. When you turn on Capacity Rebalancing, Amazon EC2 Auto Scaling attempts to launch a Spot Instance whenever Amazon EC2 notifies that a Spot Instance is at an elevated risk of interruption. After launching a new instance, it then terminates an old instance. Default: false
cooldown (Optional[Duration]) – Default scaling cooldown for this AutoScalingGroup. Default: Duration.minutes(5)
default_instance_warmup (Optional[Duration]) – The amount of time, in seconds, until a newly launched instance can contribute to the Amazon CloudWatch metrics. This delay lets an instance finish initializing before Amazon EC2 Auto Scaling aggregates instance metrics, resulting in more reliable usage data. Set this value equal to the amount of time that it takes for resource consumption to become stable after an instance reaches the InService state. To optimize the performance of scaling policies that scale continuously, such as target tracking and step scaling policies, we strongly recommend that you enable the default instance warmup, even if its value is set to 0 seconds Default instance warmup will not be added if no value is specified Default: None
desired_capacity (Union[int, float, None]) – Initial amount of instances in the fleet. If this is set to a number, every deployment will reset the amount of instances to this number. It is recommended to leave this value blank. Default: minCapacity, and leave unchanged during deployment
group_metrics (Optional[Sequence[GroupMetrics]]) – Enable monitoring for group metrics, these metrics describe the group rather than any of its instances. To report all group metrics use GroupMetrics.all() Group metrics are reported in a granularity of 1 minute at no additional charge. Default: - no group metrics will be reported
health_check (Optional[HealthCheck]) – Configuration for health checks. Default: - HealthCheck.ec2 with no grace period
ignore_unmodified_size_properties (Optional[bool]) – If the ASG has scheduled actions, don’t reset unchanged group sizes. Only used if the ASG has scheduled actions (which may scale your ASG up or down regardless of cdk deployments). If true, the size of the group will only be reset if it has been changed in the CDK app. If false, the sizes will always be changed back to what they were in the CDK app on deployment. Default: true
instance_monitoring (Optional[Monitoring]) – Controls whether instances in this group are launched with detailed or basic monitoring. When detailed monitoring is enabled, Amazon CloudWatch generates metrics every minute and your account is charged a fee. When you disable detailed monitoring, CloudWatch generates metrics every 5 minutes. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - Monitoring.DETAILED
key_name (Optional[str]) – (deprecated) Name of SSH keypair to grant access to instances. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified You can either specify keyPair or keyName, not both. Default: - No SSH access will be possible.
key_pair (Optional[IKeyPair]) – The SSH keypair to grant access to the instance. Feature flag AUTOSCALING_GENERATE_LAUNCH_TEMPLATE must be enabled to use this property. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified. You can either specify keyPair or keyName, not both. Default: - No SSH access will be possible.
max_capacity (Union[int, float, None]) – Maximum number of instances in the fleet. Default: desiredCapacity
max_instance_lifetime (Optional[Duration]) – The maximum amount of time that an instance can be in service. The maximum duration applies to all current and future instances in the group. As an instance approaches its maximum duration, it is terminated and replaced, and cannot be used again. You must specify a value of at least 604,800 seconds (7 days). To clear a previously set value, leave this property undefined. Default: none
min_capacity (Union[int, float, None]) – Minimum number of instances in the fleet. Default: 1
new_instances_protected_from_scale_in (Optional[bool]) – Whether newly-launched instances are protected from termination by Amazon EC2 Auto Scaling when scaling in. By default, Auto Scaling can terminate an instance at any time after launch when scaling in an Auto Scaling Group, subject to the group’s termination policy. However, you may wish to protect newly-launched instances from being scaled in if they are going to run critical applications that should not be prematurely terminated. This flag must be enabled if the Auto Scaling Group will be associated with an ECS Capacity Provider with managed termination protection. Default: false
notifications (Optional[Sequence[Union[NotificationConfiguration, Dict[str, Any]]]]) – Configure autoscaling group to send notifications about fleet changes to an SNS topic(s). Default: - No fleet change notifications will be sent.
signals (Optional[Signals]) – Configure waiting for signals during deployment. Use this to pause the CloudFormation deployment to wait for the instances in the AutoScalingGroup to report successful startup during creation and updates. The UserData script needs to invoke cfn-signal with a success or failure code after it is done setting up the instance. Without waiting for signals, the CloudFormation deployment will proceed as soon as the AutoScalingGroup has been created or updated but before the instances in the group have been started. For example, to have instances wait for an Elastic Load Balancing health check before they signal success, add a health-check verification by using the cfn-init helper script. For an example, see the verify_instance_health command in the Auto Scaling rolling updates sample template: https://github.com/awslabs/aws-cloudformation-templates/blob/master/aws/services/AutoScaling/AutoScalingRollingUpdates.yaml Default: - Do not wait for signals
spot_price (Optional[str]) – The maximum hourly price (in USD) to be paid for any Spot Instance launched to fulfill the request. Spot Instances are launched when the price you specify exceeds the current Spot market price. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: none
ssm_session_permissions (Optional[bool]) – Add SSM session permissions to the instance role. Setting this to true adds the necessary permissions to connect to the instance using SSM Session Manager. You can do this from the AWS Console. NOTE: Setting this flag to true may not be enough by itself. You must also use an AMI that comes with the SSM Agent, or install the SSM Agent yourself. See Working with SSM Agent in the SSM Developer Guide. Default: false
termination_policies (Optional[Sequence[TerminationPolicy]]) – A policy or a list of policies that are used to select the instances to terminate. The policies are executed in the order that you list them. Default: - TerminationPolicy.DEFAULT
termination_policy_custom_lambda_function_arn (Optional[str]) – A lambda function Arn that can be used as a custom termination policy to select the instances to terminate. This property must be specified if the TerminationPolicy.CUSTOM_LAMBDA_FUNCTION is used. Default: - No lambda function Arn will be supplied
update_policy (Optional[UpdatePolicy]) – What to do when an AutoScalingGroup’s instance configuration is changed. This is applied when any of the settings on the ASG are changed that affect how the instances should be created (VPC, instance type, startup scripts, etc.). It indicates how the existing instances should be replaced with new instances matching the new config. By default, nothing is done and only new instances are launched with the new config. Default: - UpdatePolicy.rollingUpdate() if using init, UpdatePolicy.none() otherwise
vpc_subnets (Union[SubnetSelection, Dict[str, Any], None]) – Where to place instances within the VPC. Default: - All Private subnets.
vpc (IVpc) – VPC to launch these instances in.
init (Optional[CloudFormationInit]) – Apply the given CloudFormation Init configuration to the instances in the AutoScalingGroup at startup. If you specify init, you must also specify signals to configure the number of instances to wait for and the timeout for waiting for the init process. Default: - no CloudFormation init
init_options (Union[ApplyCloudFormationInitOptions, Dict[str, Any], None]) – Use the given options for applying CloudFormation Init. Describes the configsets to use and the timeout to wait Default: - default options
instance_type (Optional[InstanceType]) – Type of instance to launch. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - Do not provide any instance type
launch_template (Optional[ILaunchTemplate]) – Launch template to use. Launch configuration related settings and MixedInstancesPolicy must not be specified when a launch template is specified. Default: - Do not provide any launch template
machine_image (Optional[IMachineImage]) – AMI to launch. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - Do not provide any machine image
max_healthy_percentage (Union[int, float, None]) – Specifies the upper threshold as a percentage of the desired capacity of the Auto Scaling group. It represents the maximum percentage of the group that can be in service and healthy, or pending, to support your workload when replacing instances. Value range is 0 to 100. After it’s set, both minHealthyPercentage and maxHealthyPercentage to -1 will clear the previously set value. Both or neither of minHealthyPercentage and maxHealthyPercentage must be specified, and the difference between them cannot be greater than 100. A large range increases the number of instances that can be replaced at the same time. Default: - No instance maintenance policy.
min_healthy_percentage (Union[int, float, None]) – Specifies the lower threshold as a percentage of the desired capacity of the Auto Scaling group. It represents the minimum percentage of the group to keep in service, healthy, and ready to use to support your workload when replacing instances. Value range is 0 to 100. After it’s set, both minHealthyPercentage and maxHealthyPercentage to -1 will clear the previously set value. Both or neither of minHealthyPercentage and maxHealthyPercentage must be specified, and the difference between them cannot be greater than 100. A large range increases the number of instances that can be replaced at the same time. Default: - No instance maintenance policy.
mixed_instances_policy (Union[MixedInstancesPolicy, Dict[str, Any], None]) – Mixed Instances Policy to use. Launch configuration related settings and Launch Template must not be specified when a MixedInstancesPolicy is specified. Default: - Do not provide any MixedInstancesPolicy
require_imdsv2 (Optional[bool]) – Whether IMDSv2 should be required on launched instances. Default: false
role (Optional[IRole]) – An IAM role to associate with the instance profile assigned to this Auto Scaling Group. The role must be assumable by the service principal ec2.amazonaws.com: launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: A role will automatically be created, it can be accessed via the role property
security_group (Optional[ISecurityGroup]) – Security group to launch the instances in. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - A SecurityGroup will be created if none is specified.
user_data (Optional[UserData]) – Specific UserData to use. The UserData may still be mutated after creation. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified Default: - A UserData object appropriate for the MachineImage’s Operating System is created.

ExampleMetadata:

infused

Example:

# vpc: ec2.Vpc
# instance_type: ec2.InstanceType
# machine_image: ec2.IMachineImage


autoscaling.AutoScalingGroup(self, "ASG",
    vpc=vpc,
    instance_type=instance_type,
    machine_image=machine_image,

    # ...

    init=ec2.CloudFormationInit.from_elements(
        ec2.InitFile.from_string("/etc/my_instance", "This got written during instance startup")),
    signals=autoscaling.Signals.wait_for_all(
        timeout=Duration.minutes(10)
    )
)

Attributes

allow_all_outbound

Whether the instances can initiate connections to anywhere by default.

Default:: true

associate_public_ip_address

Whether instances in the Auto Scaling Group should have public IP addresses associated with them.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

Use subnet setting.

auto_scaling_group_name

The name of the Auto Scaling group.

This name must be unique per Region per account.

Default:

Auto generated by CloudFormation

block_devices

Specifies how block devices are exposed to the instance. You can specify virtual devices and EBS volumes.

Each instance that is launched has an associated root device volume, either an Amazon EBS volume or an instance store volume. You can use block device mappings to specify additional EBS volumes or instance store volumes to attach to an instance when it is launched.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

Uses the block device mapping of the AMI

See:

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html

capacity_rebalance

Indicates whether Capacity Rebalancing is enabled.

When you turn on Capacity Rebalancing, Amazon EC2 Auto Scaling attempts to launch a Spot Instance whenever Amazon EC2 notifies that a Spot Instance is at an elevated risk of interruption. After launching a new instance, it then terminates an old instance.

Default:: false
See:: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-as-group.html#cfn-as-group-capacityrebalance

cooldown

Default scaling cooldown for this AutoScalingGroup.

Default:: Duration.minutes(5)

default_instance_warmup

The amount of time, in seconds, until a newly launched instance can contribute to the Amazon CloudWatch metrics.

This delay lets an instance finish initializing before Amazon EC2 Auto Scaling aggregates instance metrics, resulting in more reliable usage data. Set this value equal to the amount of time that it takes for resource consumption to become stable after an instance reaches the InService state.

To optimize the performance of scaling policies that scale continuously, such as target tracking and step scaling policies, we strongly recommend that you enable the default instance warmup, even if its value is set to 0 seconds

Default instance warmup will not be added if no value is specified

Default:: None
See:: https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-default-instance-warmup.html

desired_capacity

Initial amount of instances in the fleet.

If this is set to a number, every deployment will reset the amount of instances to this number. It is recommended to leave this value blank.

Default:: minCapacity, and leave unchanged during deployment
See:: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-as-group.html#cfn-as-group-desiredcapacity

group_metrics

Enable monitoring for group metrics, these metrics describe the group rather than any of its instances.

To report all group metrics use GroupMetrics.all() Group metrics are reported in a granularity of 1 minute at no additional charge.

Default:

no group metrics will be reported

health_check

Configuration for health checks.

Default:

HealthCheck.ec2 with no grace period

ignore_unmodified_size_properties

If the ASG has scheduled actions, don’t reset unchanged group sizes.

Only used if the ASG has scheduled actions (which may scale your ASG up or down regardless of cdk deployments). If true, the size of the group will only be reset if it has been changed in the CDK app. If false, the sizes will always be changed back to what they were in the CDK app on deployment.

Default:: true

init

Apply the given CloudFormation Init configuration to the instances in the AutoScalingGroup at startup.

If you specify init, you must also specify signals to configure the number of instances to wait for and the timeout for waiting for the init process.

Default:

no CloudFormation init

init_options

Use the given options for applying CloudFormation Init.

Describes the configsets to use and the timeout to wait

Default:

default options

instance_monitoring

Controls whether instances in this group are launched with detailed or basic monitoring.

When detailed monitoring is enabled, Amazon CloudWatch generates metrics every minute and your account is charged a fee. When you disable detailed monitoring, CloudWatch generates metrics every 5 minutes.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

Monitoring.DETAILED

See:

https://docs.aws.amazon.com/autoscaling/latest/userguide/as-instance-monitoring.html#enable-as-instance-metrics

instance_type

Type of instance to launch.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

Do not provide any instance type

key_name

(deprecated) Name of SSH keypair to grant access to instances.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

You can either specify keyPair or keyName, not both.

Default:

No SSH access will be possible.

Deprecated:

Use keyPair instead - https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_ec2-readme.html#using-an-existing-ec2-key-pair

Stability:

deprecated

key_pair

The SSH keypair to grant access to the instance.

Feature flag AUTOSCALING_GENERATE_LAUNCH_TEMPLATE must be enabled to use this property.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified.

You can either specify keyPair or keyName, not both.

Default:

No SSH access will be possible.

launch_template

Launch template to use.

Launch configuration related settings and MixedInstancesPolicy must not be specified when a launch template is specified.

Default:

Do not provide any launch template

machine_image

AMI to launch.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

Do not provide any machine image

max_capacity

Maximum number of instances in the fleet.

Default:: desiredCapacity

max_healthy_percentage

Specifies the upper threshold as a percentage of the desired capacity of the Auto Scaling group.

It represents the maximum percentage of the group that can be in service and healthy, or pending, to support your workload when replacing instances.

Value range is 0 to 100. After it’s set, both minHealthyPercentage and maxHealthyPercentage to -1 will clear the previously set value.

Both or neither of minHealthyPercentage and maxHealthyPercentage must be specified, and the difference between them cannot be greater than 100. A large range increases the number of instances that can be replaced at the same time.

Default:

No instance maintenance policy.

See:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-instance-maintenance-policy.html

max_instance_lifetime

The maximum amount of time that an instance can be in service.

The maximum duration applies to all current and future instances in the group. As an instance approaches its maximum duration, it is terminated and replaced, and cannot be used again.

You must specify a value of at least 604,800 seconds (7 days). To clear a previously set value, leave this property undefined.

Default:: none
See:: https://docs.aws.amazon.com/autoscaling/ec2/userguide/asg-max-instance-lifetime.html

min_capacity

Minimum number of instances in the fleet.

Default:: 1

min_healthy_percentage

Specifies the lower threshold as a percentage of the desired capacity of the Auto Scaling group.

It represents the minimum percentage of the group to keep in service, healthy, and ready to use to support your workload when replacing instances.

Value range is 0 to 100. After it’s set, both minHealthyPercentage and maxHealthyPercentage to -1 will clear the previously set value.

Both or neither of minHealthyPercentage and maxHealthyPercentage must be specified, and the difference between them cannot be greater than 100. A large range increases the number of instances that can be replaced at the same time.

Default:

No instance maintenance policy.

See:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-instance-maintenance-policy.html

mixed_instances_policy

Mixed Instances Policy to use.

Launch configuration related settings and Launch Template must not be specified when a MixedInstancesPolicy is specified.

Default:

Do not provide any MixedInstancesPolicy

new_instances_protected_from_scale_in

Whether newly-launched instances are protected from termination by Amazon EC2 Auto Scaling when scaling in.

By default, Auto Scaling can terminate an instance at any time after launch when scaling in an Auto Scaling Group, subject to the group’s termination policy. However, you may wish to protect newly-launched instances from being scaled in if they are going to run critical applications that should not be prematurely terminated.

This flag must be enabled if the Auto Scaling Group will be associated with an ECS Capacity Provider with managed termination protection.

Default:: false

notifications

Configure autoscaling group to send notifications about fleet changes to an SNS topic(s).

Default:

No fleet change notifications will be sent.

See:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-as-group.html#cfn-as-group-notificationconfigurations

require_imdsv2

Whether IMDSv2 should be required on launched instances.

Default:: false

role

An IAM role to associate with the instance profile assigned to this Auto Scaling Group.

The role must be assumable by the service principal ec2.amazonaws.com:

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:: A role will automatically be created, it can be accessed via the role property

Example:

role = iam.Role(self, "MyRole",
    assumed_by=iam.ServicePrincipal("ec2.amazonaws.com")
)

security_group

Security group to launch the instances in.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

A SecurityGroup will be created if none is specified.

signals

Configure waiting for signals during deployment.

Use this to pause the CloudFormation deployment to wait for the instances in the AutoScalingGroup to report successful startup during creation and updates. The UserData script needs to invoke cfn-signal with a success or failure code after it is done setting up the instance.

Without waiting for signals, the CloudFormation deployment will proceed as soon as the AutoScalingGroup has been created or updated but before the instances in the group have been started.

For example, to have instances wait for an Elastic Load Balancing health check before they signal success, add a health-check verification by using the cfn-init helper script. For an example, see the verify_instance_health command in the Auto Scaling rolling updates sample template:

https://github.com/awslabs/aws-cloudformation-templates/blob/master/aws/services/AutoScaling/AutoScalingRollingUpdates.yaml

Default:

Do not wait for signals

spot_price

The maximum hourly price (in USD) to be paid for any Spot Instance launched to fulfill the request.

Spot Instances are launched when the price you specify exceeds the current Spot market price.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:: none

ssm_session_permissions

Add SSM session permissions to the instance role.

Setting this to true adds the necessary permissions to connect to the instance using SSM Session Manager. You can do this from the AWS Console.

NOTE: Setting this flag to true may not be enough by itself. You must also use an AMI that comes with the SSM Agent, or install the SSM Agent yourself. See Working with SSM Agent in the SSM Developer Guide.

Default:: false

termination_policies

A policy or a list of policies that are used to select the instances to terminate.

The policies are executed in the order that you list them.

Default:

TerminationPolicy.DEFAULT

See:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-instance-termination.html

termination_policy_custom_lambda_function_arn

A lambda function Arn that can be used as a custom termination policy to select the instances to terminate.

This property must be specified if the TerminationPolicy.CUSTOM_LAMBDA_FUNCTION is used.

Default:

No lambda function Arn will be supplied

See:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/lambda-custom-termination-policy.html

update_policy

What to do when an AutoScalingGroup’s instance configuration is changed.

This is applied when any of the settings on the ASG are changed that affect how the instances should be created (VPC, instance type, startup scripts, etc.). It indicates how the existing instances should be replaced with new instances matching the new config. By default, nothing is done and only new instances are launched with the new config.

Default:

UpdatePolicy.rollingUpdate() if using init, UpdatePolicy.none() otherwise

user_data

Specific UserData to use.

The UserData may still be mutated after creation.

launchTemplate and mixedInstancesPolicy must not be specified when this property is specified

Default:

A UserData object appropriate for the MachineImage’s

Operating System is created.

vpc: VPC to launch these instances in.

vpc_subnets

Where to place instances within the VPC.

Default:

All Private subnets.