Class AutoScalingGroupProps

Properties of a Fleet.

Inheritance
object
AutoScalingGroupProps
Inherited Members
Namespace: Amazon.CDK.AWS.AutoScaling
Assembly: Amazon.CDK.Lib.dll
Syntax (csharp)
public class AutoScalingGroupProps : IAutoScalingGroupProps, ICommonAutoScalingGroupProps
Syntax (vb)
Public Class AutoScalingGroupProps Implements IAutoScalingGroupProps, ICommonAutoScalingGroupProps
Remarks

ExampleMetadata: infused

Examples
Vpc vpc;


            var mySecurityGroup = new SecurityGroup(this, "SecurityGroup", new SecurityGroupProps { Vpc = vpc });
            new AutoScalingGroup(this, "ASG", new AutoScalingGroupProps {
                Vpc = vpc,
                InstanceType = InstanceType.Of(InstanceClass.BURSTABLE2, InstanceSize.MICRO),
                MachineImage = MachineImage.LatestAmazonLinux2(),
                SecurityGroup = mySecurityGroup
            });

Synopsis

Constructors

AutoScalingGroupProps()

Properties of a Fleet.

Properties

AllowAllOutbound

Whether the instances can initiate connections to anywhere by default.
AssociatePublicIpAddress

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

The name of the Auto Scaling group.
AzCapacityDistributionStrategy

The strategy for distributing instances across Availability Zones.
BlockDevices

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

Indicates whether Capacity Rebalancing is enabled.
Cooldown

Default scaling cooldown for this AutoScalingGroup.
DefaultInstanceWarmup

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

Initial amount of instances in the fleet.
GroupMetrics

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

(deprecated) Configuration for health checks.
HealthChecks

Configuration for EC2 or additional health checks.
IgnoreUnmodifiedSizeProperties

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

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

Use the given options for applying CloudFormation Init.
InstanceMonitoring

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

Type of instance to launch.
KeyName

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

The SSH keypair to grant access to the instance.
LaunchTemplate

Launch template to use.
MachineImage

AMI to launch.
MaxCapacity

Maximum number of instances in the fleet.
MaxHealthyPercentage

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

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

Whether safety guardrail should be enforced when migrating to the launch template.
MinCapacity

Minimum number of instances in the fleet.
MinHealthyPercentage

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

Mixed Instances Policy to use.
NewInstancesProtectedFromScaleIn

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

Configure autoscaling group to send notifications about fleet changes to an SNS topic(s).
RequireImdsv2

Whether IMDSv2 should be required on launched instances.
Role

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

Security group to launch the instances in.
Signals

Configure waiting for signals during deployment.
SpotPrice

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

Add SSM session permissions to the instance role.
TerminationPolicies

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

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

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

Specific UserData to use.
Vpc

VPC to launch these instances in.
VpcSubnets

Where to place instances within the VPC.

Constructors

AutoScalingGroupProps()

Properties of a Fleet.

public AutoScalingGroupProps()
Remarks

ExampleMetadata: infused

Examples
Vpc vpc;


            var mySecurityGroup = new SecurityGroup(this, "SecurityGroup", new SecurityGroupProps { Vpc = vpc });
            new AutoScalingGroup(this, "ASG", new AutoScalingGroupProps {
                Vpc = vpc,
                InstanceType = InstanceType.Of(InstanceClass.BURSTABLE2, InstanceSize.MICRO),
                MachineImage = MachineImage.LatestAmazonLinux2(),
                SecurityGroup = mySecurityGroup
            });

Properties

AllowAllOutbound

Whether the instances can initiate connections to anywhere by default.

public bool? AllowAllOutbound { get; set; }
Property Value

bool?

Remarks

Default: true

AssociatePublicIpAddress

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

public bool? AssociatePublicIpAddress { get; set; }
Property Value

bool?

Remarks

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

Default: - Use subnet setting.

AutoScalingGroupName

The name of the Auto Scaling group.

public string? AutoScalingGroupName { get; set; }
Property Value

string

Remarks

This name must be unique per Region per account.

Default: - Auto generated by CloudFormation

AzCapacityDistributionStrategy

The strategy for distributing instances across Availability Zones.

public CapacityDistributionStrategy? AzCapacityDistributionStrategy { get; set; }
Property Value

CapacityDistributionStrategy?

Remarks

Default: None

BlockDevices

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

public IBlockDevice[]? BlockDevices { get; set; }
Property Value

IBlockDevice[]

Remarks

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

CapacityRebalance

Indicates whether Capacity Rebalancing is enabled.

public bool? CapacityRebalance { get; set; }
Property Value

bool?

Remarks

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.

public Duration? Cooldown { get; set; }
Property Value

Duration

Remarks

Default: Duration.minutes(5)

DefaultInstanceWarmup

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

public Duration? DefaultInstanceWarmup { get; set; }
Property Value

Duration

Remarks

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

DesiredCapacity

Initial amount of instances in the fleet.

public double? DesiredCapacity { get; set; }
Property Value

double?

Remarks

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

GroupMetrics

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

public GroupMetrics[]? GroupMetrics { get; set; }
Property Value

GroupMetrics[]

Remarks

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

HealthCheck

(deprecated) Configuration for health checks.

[Obsolete("Use `healthChecks` instead")]
public HealthCheck? HealthCheck { get; set; }
Property Value

HealthCheck

Remarks

Default: - HealthCheck.ec2 with no grace period

Stability: Deprecated

HealthChecks

Configuration for EC2 or additional health checks.

public HealthChecks? HealthChecks { get; set; }
Property Value

HealthChecks

Remarks

Even when using HealthChecks.withAdditionalChecks(), the EC2 type is implicitly included.

Default: - EC2 type with no grace period

See: https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-health-checks.html

IgnoreUnmodifiedSizeProperties

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

public bool? IgnoreUnmodifiedSizeProperties { get; set; }
Property Value

bool?

Remarks

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.

public CloudFormationInit? Init { get; set; }
Property Value

CloudFormationInit

Remarks

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

InitOptions

Use the given options for applying CloudFormation Init.

public IApplyCloudFormationInitOptions? InitOptions { get; set; }
Property Value

IApplyCloudFormationInitOptions

Remarks

Describes the configsets to use and the timeout to wait

Default: - default options

InstanceMonitoring

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

public Monitoring? InstanceMonitoring { get; set; }
Property Value

Monitoring?

Remarks

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

InstanceType

Type of instance to launch.

public InstanceType? InstanceType { get; set; }
Property Value

InstanceType

Remarks

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

Default: - Do not provide any instance type

KeyName

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

[Obsolete("- 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")]
public string? KeyName { get; set; }
Property Value

string

Remarks

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.

Stability: Deprecated

KeyPair

The SSH keypair to grant access to the instance.

public IKeyPair? KeyPair { get; set; }
Property Value

IKeyPair

Remarks

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.

LaunchTemplate

Launch template to use.

public ILaunchTemplate? LaunchTemplate { get; set; }
Property Value

ILaunchTemplate

Remarks

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

Default: - Do not provide any launch template

MachineImage

AMI to launch.

public IMachineImage? MachineImage { get; set; }
Property Value

IMachineImage

Remarks

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

Default: - Do not provide any machine image

MaxCapacity

Maximum number of instances in the fleet.

public double? MaxCapacity { get; set; }
Property Value

double?

Remarks

Default: desiredCapacity

MaxHealthyPercentage

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

public double? MaxHealthyPercentage { get; set; }
Property Value

double?

Remarks

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

MaxInstanceLifetime

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

public Duration? MaxInstanceLifetime { get; set; }
Property Value

Duration

Remarks

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

See: https://docs.aws.amazon.com/autoscaling/ec2/userguide/asg-max-instance-lifetime.html

MigrateToLaunchTemplate

Whether safety guardrail should be enforced when migrating to the launch template.

public bool? MigrateToLaunchTemplate { get; set; }
Property Value

bool?

Remarks

Default: false

MinCapacity

Minimum number of instances in the fleet.

public double? MinCapacity { get; set; }
Property Value

double?

Remarks

Default: 1

MinHealthyPercentage

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

public double? MinHealthyPercentage { get; set; }
Property Value

double?

Remarks

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

MixedInstancesPolicy

Mixed Instances Policy to use.

public IMixedInstancesPolicy? MixedInstancesPolicy { get; set; }
Property Value

IMixedInstancesPolicy

Remarks

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

Default: - Do not provide any MixedInstancesPolicy

NewInstancesProtectedFromScaleIn

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

public bool? NewInstancesProtectedFromScaleIn { get; set; }
Property Value

bool?

Remarks

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).

public INotificationConfiguration[]? Notifications { get; set; }
Property Value

INotificationConfiguration[]

Remarks

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

RequireImdsv2

Whether IMDSv2 should be required on launched instances.

public bool? RequireImdsv2 { get; set; }
Property Value

bool?

Remarks

Default: false

Role

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

public IRole? Role { get; set; }
Property Value

IRole

Remarks

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

Examples
var role = new Role(this, "MyRole", new RoleProps {
                 AssumedBy = new ServicePrincipal("ec2.amazonaws.com")
             });

SecurityGroup

Security group to launch the instances in.

public ISecurityGroup? SecurityGroup { get; set; }
Property Value

ISecurityGroup

Remarks

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.

public Signals? Signals { get; set; }
Property Value

Signals

Remarks

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

SpotPrice

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

public string? SpotPrice { get; set; }
Property Value

string

Remarks

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

SsmSessionPermissions

Add SSM session permissions to the instance role.

public bool? SsmSessionPermissions { get; set; }
Property Value

bool?

Remarks

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

TerminationPolicies

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

public TerminationPolicy[]? TerminationPolicies { get; set; }
Property Value

TerminationPolicy[]

Remarks

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

TerminationPolicyCustomLambdaFunctionArn

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

public string? TerminationPolicyCustomLambdaFunctionArn { get; set; }
Property Value

string

Remarks

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

UpdatePolicy

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

public UpdatePolicy? UpdatePolicy { get; set; }
Property Value

UpdatePolicy

Remarks

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

UserData

Specific UserData to use.

public UserData? UserData { get; set; }
Property Value

UserData

Remarks

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.

public IVpc Vpc { get; set; }
Property Value

IVpc

Remarks

ExampleMetadata: infused

VpcSubnets

Where to place instances within the VPC.

public ISubnetSelection? VpcSubnets { get; set; }
Property Value

ISubnetSelection

Remarks

Default: - All Private subnets.

Implements