AutoScalingGroup

class aws_cdk.aws_autoscaling.AutoScalingGroup(scope, id, *, 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, 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, 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)

Bases: Resource

A Fleet represents a managed set of EC2 instances.

The Fleet models a number of AutoScalingGroups, a launch configuration, a security group and an instance role.

It allows adding arbitrary commands to the startup scripts of the instances in the fleet.

The ASG spans the availability zones specified by vpcSubnets, falling back to the Vpc default strategy if not specified.

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)
    )
)

Parameters:

scope (Construct) –
id (str) –
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.
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]) – Name of SSH keypair to grant access to instances. launchTemplate and mixedInstancesPolicy must not be specified when this property is specified 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.

Methods

add_lifecycle_hook(id, *, lifecycle_transition, default_result=None, heartbeat_timeout=None, lifecycle_hook_name=None, notification_metadata=None, notification_target=None, role=None)

Send a message to either an SQS queue or SNS topic when instances launch or terminate.

Parameters:

id (str) –
lifecycle_transition (LifecycleTransition) – The state of the Amazon EC2 instance to which you want to attach the lifecycle hook.
default_result (Optional[DefaultResult]) – The action the Auto Scaling group takes when the lifecycle hook timeout elapses or if an unexpected failure occurs. Default: Continue
heartbeat_timeout (Optional[Duration]) – Maximum time between calls to RecordLifecycleActionHeartbeat for the hook. If the lifecycle hook times out, perform the action in DefaultResult. Default: - No heartbeat timeout.
lifecycle_hook_name (Optional[str]) – Name of the lifecycle hook. Default: - Automatically generated name.
notification_metadata (Optional[str]) – Additional data to pass to the lifecycle hook target. Default: - No metadata.
notification_target (Optional[ILifecycleHookTarget]) – The target of the lifecycle hook. Default: - No target.
role (Optional[IRole]) – The role that allows publishing to the notification target. Default: - A role will be created if a target is provided. Otherwise, no role is created.

Return type:

LifecycleHook

add_security_group(security_group)

Add the security group to all instances via the launch template security groups array.

Parameters:: security_group (ISecurityGroup) – : The security group to add.
Return type:: None

add_to_role_policy(statement)

Adds a statement to the IAM role assumed by instances of this fleet.

Parameters:

statement (PolicyStatement) –

Return type:

None

add_user_data(*commands)

Add command to the startup script of fleet instances.

The command must be in the scripting language supported by the fleet’s OS (i.e. Linux/Windows). Does nothing for imported ASGs.

Parameters:

commands (str) –

Return type:

None

add_warm_pool(*, max_group_prepared_capacity=None, min_size=None, pool_state=None, reuse_on_scale_in=None)

Add a pool of pre-initialized EC2 instances that sits alongside an Auto Scaling group.

Parameters:

max_group_prepared_capacity (Union[int, float, None]) – The maximum number of instances that are allowed to be in the warm pool or in any state except Terminated for the Auto Scaling group. If the value is not specified, Amazon EC2 Auto Scaling launches and maintains the difference between the group’s maximum capacity and its desired capacity. Default: - max size of the Auto Scaling group
min_size (Union[int, float, None]) – The minimum number of instances to maintain in the warm pool. Default: 0
pool_state (Optional[PoolState]) – The instance state to transition to after the lifecycle actions are complete. Default: PoolState.STOPPED
reuse_on_scale_in (Optional[bool]) – Indicates whether instances in the Auto Scaling group can be returned to the warm pool on scale in. If the value is not specified, instances in the Auto Scaling group will be terminated when the group scales in. Default: false

Return type:

WarmPool

apply_cloud_formation_init(init, *, config_sets=None, embed_fingerprint=None, ignore_failures=None, include_role=None, include_url=None, print_log=None)

Use a CloudFormation Init configuration at instance startup.

This does the following:

Attaches the CloudFormation Init metadata to the AutoScalingGroup resource.
Add commands to the UserData to run cfn-init and cfn-signal.
Update the instance’s CreationPolicy to wait for cfn-init to finish before reporting success.

Parameters:

init (CloudFormationInit) –
config_sets (Optional[Sequence[str]]) – ConfigSet to activate. Default: [‘default’]
embed_fingerprint (Optional[bool]) – Force instance replacement by embedding a config fingerprint. If true (the default), a hash of the config will be embedded into the UserData, so that if the config changes, the UserData changes and instances will be replaced (given an UpdatePolicy has been configured on the AutoScalingGroup). If false, no such hash will be embedded, and if the CloudFormation Init config changes nothing will happen to the running instances. If a config update introduces errors, you will not notice until after the CloudFormation deployment successfully finishes and the next instance fails to launch. Default: true
ignore_failures (Optional[bool]) – Don’t fail the instance creation when cfn-init fails. You can use this to prevent CloudFormation from rolling back when instances fail to start up, to help in debugging. Default: false
include_role (Optional[bool]) – Include –role argument when running cfn-init and cfn-signal commands. This will be the IAM instance profile attached to the EC2 instance Default: false
include_url (Optional[bool]) – Include –url argument when running cfn-init and cfn-signal commands. This will be the cloudformation endpoint in the deployed region e.g. https://cloudformation.us-east-1.amazonaws.com Default: false
print_log (Optional[bool]) – Print the results of running cfn-init to the Instance System Log. By default, the output of running cfn-init is written to a log file on the instance. Set this to true to print it to the System Log (visible from the EC2 Console), false to not print it. (Be aware that the system log is refreshed at certain points in time of the instance life cycle, and successful execution may not always show up). Default: true

Return type:

None

apply_removal_policy(policy)

Apply the given removal policy to this resource.

The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you’ve removed it from the CDK application or because you’ve made a change that requires the resource to be replaced.

The resource can be deleted (RemovalPolicy.DESTROY), or left in your AWS account for data recovery and cleanup later (RemovalPolicy.RETAIN).

Parameters:

policy (RemovalPolicy) –

Return type:

None

are_new_instances_protected_from_scale_in()

Returns true if newly-launched instances are protected from scale-in.

Return type:: bool

attach_to_application_target_group(target_group)

Attach to ELBv2 Application Target Group.

Parameters:

target_group (IApplicationTargetGroup) –

Return type:

LoadBalancerTargetProps

attach_to_classic_lb(load_balancer)

Attach to a classic load balancer.

Parameters:

load_balancer (LoadBalancer) –

Return type:

None

attach_to_network_target_group(target_group)

Attach to ELBv2 Application Target Group.

Parameters:

target_group (INetworkTargetGroup) –

Return type:

LoadBalancerTargetProps

protect_new_instances_from_scale_in()

Ensures newly-launched instances are protected from scale-in.

Return type:: None

scale_on_cpu_utilization(id, *, target_utilization_percent, cooldown=None, disable_scale_in=None, estimated_instance_warmup=None)

Scale out or in to achieve a target CPU utilization.

Parameters:

id (str) –
target_utilization_percent (Union[int, float]) – Target average CPU utilization across the task.
cooldown (Optional[Duration]) – Period after a scaling completes before another scaling activity can start. Default: - The default cooldown configured on the AutoScalingGroup.
disable_scale_in (Optional[bool]) – Indicates whether scale in by the target tracking policy is disabled. If the value is true, scale in is disabled and the target tracking policy won’t remove capacity from the autoscaling group. Otherwise, scale in is enabled and the target tracking policy can remove capacity from the group. Default: false
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: - Same as the cooldown.

Return type:

TargetTrackingScalingPolicy

scale_on_incoming_bytes(id, *, target_bytes_per_second, cooldown=None, disable_scale_in=None, estimated_instance_warmup=None)

Scale out or in to achieve a target network ingress rate.

Parameters:

id (str) –
target_bytes_per_second (Union[int, float]) – Target average bytes/seconds on each instance.
cooldown (Optional[Duration]) – Period after a scaling completes before another scaling activity can start. Default: - The default cooldown configured on the AutoScalingGroup.
disable_scale_in (Optional[bool]) – Indicates whether scale in by the target tracking policy is disabled. If the value is true, scale in is disabled and the target tracking policy won’t remove capacity from the autoscaling group. Otherwise, scale in is enabled and the target tracking policy can remove capacity from the group. Default: false
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: - Same as the cooldown.

Return type:

TargetTrackingScalingPolicy

scale_on_metric(id, *, metric, scaling_steps, adjustment_type=None, cooldown=None, datapoints_to_alarm=None, estimated_instance_warmup=None, evaluation_periods=None, metric_aggregation_type=None, min_adjustment_magnitude=None)

Scale out or in, in response to a metric.

Parameters:

id (str) –
metric (IMetric) – Metric to scale on.
scaling_steps (Sequence[Union[ScalingInterval, Dict[str, Any]]]) – The intervals for scaling. Maps a range of metric values to a particular scaling behavior. Must be between 2 and 40 steps.
adjustment_type (Optional[AdjustmentType]) – How the adjustment numbers inside ‘intervals’ are interpreted. Default: ChangeInCapacity
cooldown (Optional[Duration]) – Grace period after scaling activity. Default: Default cooldown period on your AutoScalingGroup
datapoints_to_alarm (Union[int, float, None]) – The number of data points out of the evaluation periods that must be breaching to trigger a scaling action. Creates an “M out of N” alarm, where this property is the M and the value set for evaluationPeriods is the N value. Only has meaning if evaluationPeriods != 1. Must be less than or equal to evaluationPeriods. Default: - Same as evaluationPeriods
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: Same as the cooldown
evaluation_periods (Union[int, float, None]) – How many evaluation periods of the metric to wait before triggering a scaling action. Raising this value can be used to smooth out the metric, at the expense of slower response times. If datapointsToAlarm is not set, then all data points in the evaluation period must meet the criteria to trigger a scaling action. Default: 1
metric_aggregation_type (Optional[MetricAggregationType]) – Aggregation to apply to all data points over the evaluation periods. Only has meaning if evaluationPeriods != 1. Default: - The statistic from the metric if applicable (MIN, MAX, AVERAGE), otherwise AVERAGE.
min_adjustment_magnitude (Union[int, float, None]) – Minimum absolute number to adjust capacity with as result of percentage scaling. Only when using AdjustmentType = PercentChangeInCapacity, this number controls the minimum absolute effect size. Default: No minimum scaling effect

Return type:

StepScalingPolicy

scale_on_outgoing_bytes(id, *, target_bytes_per_second, cooldown=None, disable_scale_in=None, estimated_instance_warmup=None)

Scale out or in to achieve a target network egress rate.

Parameters:

id (str) –
target_bytes_per_second (Union[int, float]) – Target average bytes/seconds on each instance.
cooldown (Optional[Duration]) – Period after a scaling completes before another scaling activity can start. Default: - The default cooldown configured on the AutoScalingGroup.
disable_scale_in (Optional[bool]) – Indicates whether scale in by the target tracking policy is disabled. If the value is true, scale in is disabled and the target tracking policy won’t remove capacity from the autoscaling group. Otherwise, scale in is enabled and the target tracking policy can remove capacity from the group. Default: false
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: - Same as the cooldown.

Return type:

TargetTrackingScalingPolicy

scale_on_request_count(id, *, target_requests_per_minute=None, cooldown=None, disable_scale_in=None, estimated_instance_warmup=None)

Scale out or in to achieve a target request handling rate.

The AutoScalingGroup must have been attached to an Application Load Balancer in order to be able to call this.

Parameters:

id (str) –
target_requests_per_minute (Union[int, float, None]) – Target average requests/minute on each instance. Default: - Specify exactly one of ‘targetRequestsPerMinute’ and ‘targetRequestsPerSecond’
cooldown (Optional[Duration]) – Period after a scaling completes before another scaling activity can start. Default: - The default cooldown configured on the AutoScalingGroup.
disable_scale_in (Optional[bool]) – Indicates whether scale in by the target tracking policy is disabled. If the value is true, scale in is disabled and the target tracking policy won’t remove capacity from the autoscaling group. Otherwise, scale in is enabled and the target tracking policy can remove capacity from the group. Default: false
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: - Same as the cooldown.

Return type:

TargetTrackingScalingPolicy

scale_on_schedule(id, *, schedule, desired_capacity=None, end_time=None, max_capacity=None, min_capacity=None, start_time=None, time_zone=None)

Scale out or in based on time.

Parameters:

id (str) –
schedule (Schedule) – When to perform this action. Supports cron expressions. For more information about cron expressions, see https://en.wikipedia.org/wiki/Cron.
desired_capacity (Union[int, float, None]) – The new desired capacity. At the scheduled time, set the desired capacity to the given capacity. At least one of maxCapacity, minCapacity, or desiredCapacity must be supplied. Default: - No new desired capacity.
end_time (Optional[datetime]) – When this scheduled action expires. Default: - The rule never expires.
max_capacity (Union[int, float, None]) – The new maximum capacity. At the scheduled time, set the maximum capacity to the given capacity. At least one of maxCapacity, minCapacity, or desiredCapacity must be supplied. Default: - No new maximum capacity.
min_capacity (Union[int, float, None]) – The new minimum capacity. At the scheduled time, set the minimum capacity to the given capacity. At least one of maxCapacity, minCapacity, or desiredCapacity must be supplied. Default: - No new minimum capacity.
start_time (Optional[datetime]) – When this scheduled action becomes active. Default: - The rule is activate immediately.
time_zone (Optional[str]) – Specifies the time zone for a cron expression. If a time zone is not provided, UTC is used by default. Valid values are the canonical names of the IANA time zones, derived from the IANA Time Zone Database (such as Etc/GMT+9 or Pacific/Tahiti). For more information, see https://en.wikipedia.org/wiki/List_of_tz_database_time_zones. Default: - UTC

Return type:

ScheduledAction

scale_to_track_metric(id, *, metric, target_value, cooldown=None, disable_scale_in=None, estimated_instance_warmup=None)

Scale out or in in order to keep a metric around a target value.

Parameters:

id (str) –
metric (IMetric) – Metric to track. The metric must represent a utilization, so that if it’s higher than the target value, your ASG should scale out, and if it’s lower it should scale in.
target_value (Union[int, float]) – Value to keep the metric around.
cooldown (Optional[Duration]) – Period after a scaling completes before another scaling activity can start. Default: - The default cooldown configured on the AutoScalingGroup.
disable_scale_in (Optional[bool]) – Indicates whether scale in by the target tracking policy is disabled. If the value is true, scale in is disabled and the target tracking policy won’t remove capacity from the autoscaling group. Otherwise, scale in is enabled and the target tracking policy can remove capacity from the group. Default: false
estimated_instance_warmup (Optional[Duration]) – Estimated time until a newly launched instance can send metrics to CloudWatch. Default: - Same as the cooldown.

Return type:

TargetTrackingScalingPolicy

to_string()

Returns a string representation of this construct.

Return type:: str

Attributes

auto_scaling_group_arn: Arn of the AutoScalingGroup.

auto_scaling_group_name: Name of the AutoScalingGroup.

connections: The network connections associated with this resource.

env

The environment this resource belongs to.

For resources that are created and managed by the CDK (generally, those created by creating new class instances like Role, Bucket, etc.), this is always the same as the environment of the stack they belong to; however, for imported resources (those obtained from static methods like fromRoleArn, fromBucketName, etc.), that might be different than the stack they were imported into.

grant_principal: The principal to grant permissions to.

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

node: The tree node.

os_type: The type of OS instances of this fleet are running.

role

The IAM Role in the instance profile.

Throws:: an error if a launch template is given

spot_price

The maximum spot price configured for the autoscaling group.

undefined indicates that this group uses on-demand capacity.

stack: The stack in which this resource is defined.

user_data

The Base64-encoded user data to make available to the launched EC2 instances.

Throws:: an error if a launch template is given and it does not provide a non-null userData

Static Methods

classmethod from_auto_scaling_group_name(scope, id, auto_scaling_group_name)

Parameters:

scope (Construct) –
id (str) –
auto_scaling_group_name (str) –

Return type:

IAutoScalingGroup

classmethod is_construct(x)

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters:: x (Any) – Any object.
Return type:: bool
Returns:: true if x is an object created from a class which extends Construct.

classmethod is_owned_resource(construct)

Returns true if the construct was created by CDK, and false otherwise.

Parameters:

construct (IConstruct) –

Return type:

bool

classmethod is_resource(construct)

Check whether the given construct is a Resource.

Parameters:

construct (IConstruct) –

Return type:

bool