AutoScalingGroup

Whether the instances can initiate connections to anywhere by default.

Default: true

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.

The name of the Auto Scaling group. This name must be unique per Region per account.

Default: - Auto generated by CloudFormation

The strategy for distributing instances across Availability Zones.

Default: None

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

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

Default scaling cooldown for this AutoScalingGroup.

Default: Duration.minutes(5)

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

Deletion protection for the Auto Scaling group.

Default: DeletionProtection.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

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

Configuration for health checks.

Default: - HealthCheck.ec2 with no grace period

Deprecated: Use `healthChecks` instead

Configuration for EC2 or additional health checks. Even when using `HealthChecks.withAdditionalChecks()`, the EC2 type is implicitly included.

Default: - EC2 type with no grace period

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

An instance lifecycle policy that defines how instances should be handled during lifecycle events, particularly when lifecycle hooks are abandoned or fail.

Default: None

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

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

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.

Maximum number of instances in the fleet.

Default: desiredCapacity

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 86,400 seconds (one day). To clear a previously set value, leave this property undefined.

Default: none

Minimum number of instances in the fleet.

Default: 1

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

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

Default: - No fleet change notifications will be sent.

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

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

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](https://docs.aws.amazon.com/systems-manager/latest/userguide/ssm-agent.html) in the SSM Developer Guide.

Default: false

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`

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

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

Where to place instances within the VPC.

Default: - All Private subnets.