AWS Documentation » AWS CloudFormation » User Guide » Template Reference » AWS Resource and Property Types Reference » Amazon EC2 Auto Scaling Resource Types Reference » AWS::AutoScaling::LifecycleHook

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AWS::AutoScaling::LifecycleHook

Defines lifecycle hooks for an Amazon EC2 Auto Scaling group, which specify actions to perform when Amazon EC2 Auto Scaling launches or terminates instances. When you use a lifecycle hook, the Auto Scaling group pauses the instance either after it is launched (before it is put into service) or as it is terminated (before it is fully terminated). For more information, see Amazon EC2 Auto Scaling Lifecycle Hooks in the Amazon EC2 Auto Scaling User Guide.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "Type" : "AWS::AutoScaling::LifecycleHook",
  "Properties" : {
    "AutoScalingGroupName" : String,
    "DefaultResult" : String,
    "HeartbeatTimeout" : Integer,
    "LifecycleHookName" : String,
    "LifecycleTransition" : String,
    "NotificationMetadata" : String,
    "NotificationTargetARN" : String,
    "RoleARN" : String
  }
}

YAML

Type: AWS::AutoScaling::LifecycleHook
Properties:
  AutoScalingGroupName: String
  DefaultResult: String
  HeartbeatTimeout: Integer
  LifecycleHookName: String
  LifecycleTransition: String
  NotificationMetadata: String
  NotificationTargetARN: String
  RoleARN: String

Properties

For information about valid and default values, see PutLifecycleHook in the Amazon EC2 Auto Scaling API Reference.

AutoScalingGroupName

The name of the Auto Scaling group for the lifecycle hook.

Required: Yes

Type: String

Update requires: Replacement

DefaultResult

The action the Auto Scaling group takes when the lifecycle hook timeout elapses or if an unexpected failure occurs. Valid values are CONTINUE and ABANDON (default).

Required: No

Type: String

Update requires: No interruption

HeartbeatTimeout

The amount of time (in seconds) that can elapse before the lifecycle hook times out. When the lifecycle hook times out, Amazon EC2 Auto Scaling performs the action that you specified in the DefaultResult property.

Required: No

Type: Integer

Update requires: No interruption

LifecycleHookName

The name of the lifecycle hook. Length Constraints: Minimum length of 1. Maximum length of 255.

Required: No

Type: String

Update requires: Replacement

LifecycleTransition

The state of the Amazon EC2 instance to which you want to attach the lifecycle hook. For valid values, see the LifecycleTransition details for the PutLifecycleHook action in the Amazon EC2 Auto Scaling API Reference.

Required: Yes

Type: String

Update requires: No interruption

NotificationMetadata

Additional information that you want to include when Amazon EC2 Auto Scaling sends a message to the notification target.

Required: No

Type: String

Update requires: No interruption

NotificationTargetARN

The Amazon resource name (ARN) of the notification target that Amazon EC2 Auto Scaling uses to notify you when an instance is in the transition state for the lifecycle hook. You can specify an Amazon SQS queue or an Amazon SNS topic. The notification message includes the following information: lifecycle action token, user account ID, Auto Scaling group name, lifecycle hook name, instance ID, lifecycle transition, and notification metadata.

Required: No

Type: String

Update requires: No interruption

RoleARN

The ARN of the IAM role that allows the Auto Scaling group to publish to the specified notification target. The role requires permissions to Amazon SNS and Amazon SQS.

Required: No

Type: String

Update requires: No interruption

Return Value

When the logical ID of this resource is provided to the Ref intrinsic function, Ref returns the resource name. For example:

{ "Ref": "myLifecycleHook" }

Ref returns the lifecycle hook name, such as mylifecyclehookname.

For more information about using the Ref function, see Ref.

Example

In the following template snippet, the Amazon EC2 Auto Scaling pauses instances before completely terminating them. While in the pending state, you can, for example, connect to the instance and download logs or any other data before the instance is terminated.

JSON

"myLifecycleHook": {
  "Type": "AWS::AutoScaling::LifecycleHook",
  "Properties": {
    "AutoScalingGroupName": { "Ref": "myAutoScalingGroup" },
    "LifecycleTransition": "autoscaling:EC2_INSTANCE_TERMINATING",
    "NotificationTargetARN": { "Ref": "lifecycleHookTopic" },
    "RoleARN": { "Fn::GetAtt": [ "lifecycleHookRole", "Arn" ] }
  }
}

YAML

myLifecycleHook: 
  Type: AWS::AutoScaling::LifecycleHook
  Properties: 
    AutoScalingGroupName: 
      Ref: myAutoScalingGroup
    LifecycleTransition: "autoscaling:EC2_INSTANCE_TERMINATING"
    NotificationTargetARN: 
      Ref: lifecycleHookTopic
    RoleARN: 
      Fn::GetAtt: 
        - lifecycleHookRole
        - Arn

See Also

• PutLifecycleHook in the Amazon EC2 Auto Scaling API Reference (for valid values and default values)

• Amazon EC2 Auto Scaling Lifecycle Hooks in the Amazon EC2 Auto Scaling User Guide