Amazon EC2 Auto Scaling
API Reference (API Version 2011-01-01)

PutLifecycleHook

Creates or updates a lifecycle hook for the specified Auto Scaling group.

A lifecycle hook tells Amazon EC2 Auto Scaling to perform an action on an instance when the instance launches (before it is put into service) or as the instance terminates (before it is fully terminated).

This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group:

  1. (Optional) Create a Lambda function and a rule that allows CloudWatch Events to invoke your Lambda function when Amazon EC2 Auto Scaling launches or terminates instances.

  2. (Optional) Create a notification target and an IAM role. The target can be either an Amazon SQS queue or an Amazon SNS topic. The role allows Amazon EC2 Auto Scaling to publish lifecycle notifications to the target.

  3. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate.

  4. If you need more time, record the lifecycle action heartbeat to keep the instance in a pending state using using RecordLifecycleActionHeartbeat.

  5. If you finish before the timeout period ends, complete the lifecycle action using CompleteLifecycleAction.

For more information, see Amazon EC2 Auto Scaling Lifecycle Hooks in the Amazon EC2 Auto Scaling User Guide.

If you exceed your maximum limit of lifecycle hooks, which by default is 50 per Auto Scaling group, the call fails.

You can view the lifecycle hooks for an Auto Scaling group using DescribeLifecycleHooks. If you are no longer using a lifecycle hook, you can delete it using DeleteLifecycleHook.

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

AutoScalingGroupName

The name of the Auto Scaling group.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1600.

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: Yes

DefaultResult

Defines the action the Auto Scaling group should take when the lifecycle hook timeout elapses or if an unexpected failure occurs. This parameter can be either CONTINUE or ABANDON. The default value is ABANDON.

Type: String

Required: No

HeartbeatTimeout

The maximum time, in seconds, that can elapse before the lifecycle hook times out. The range is from 30 to 7200 seconds. The default value is 3600 seconds (1 hour).

If the lifecycle hook times out, Amazon EC2 Auto Scaling performs the action that you specified in the DefaultResult parameter. You can prevent the lifecycle hook from timing out by calling RecordLifecycleActionHeartbeat.

Type: Integer

Required: No

LifecycleHookName

The name of the lifecycle hook.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 255.

Pattern: [A-Za-z0-9\-_\/]+

Required: Yes

LifecycleTransition

The instance state to which you want to attach the lifecycle hook. The valid values are:

  • autoscaling:EC2_INSTANCE_LAUNCHING

  • autoscaling:EC2_INSTANCE_TERMINATING

Conditional: This parameter is required for new lifecycle hooks, but optional when updating existing hooks.

Type: String

Required: No

NotificationMetadata

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

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1023.

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No

NotificationTargetARN

The 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. This target can be either an SQS queue or an SNS topic.

If you specify an empty string, this overrides the current ARN.

This operation uses the JSON format when sending notifications to an Amazon SQS queue, and an email key-value pair format when sending notifications to an Amazon SNS topic.

When you specify a notification target, Amazon EC2 Auto Scaling sends it a test message. Test messages contain the following additional key-value pair: "Event": "autoscaling:TEST_NOTIFICATION".

Type: String

Length Constraints: Minimum length of 0. Maximum length of 1600.

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No

RoleARN

The ARN of the IAM role that allows the Auto Scaling group to publish to the specified notification target, for example, an Amazon SNS topic or an Amazon SQS queue.

Conditional: This parameter is required for new lifecycle hooks, but optional when updating existing hooks.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1600.

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Required: No

Errors

For information about the errors that are common to all actions, see Common Errors.

LimitExceeded

You have already reached a limit for your Amazon EC2 Auto Scaling resources (for example, Auto Scaling groups, launch configurations, or lifecycle hooks). For more information, see DescribeAccountLimits.

HTTP Status Code: 400

ResourceContention

You already have a pending update to an Amazon EC2 Auto Scaling resource (for example, an Auto Scaling group, instance, or load balancer).

HTTP Status Code: 500

Example

Sample Request

http://autoscaling.amazonaws.com/?Action=PutLifecycleHook &LifecycleHookName=my-launch-hook &AutoScalingGroupName=my-asg &LifecycleTransition=autoscaling:EC2_INSTANCE_LAUNCHING &NotificationTargetARN=arn:aws:sqs:us-east-1:123456789012:my-queue &RoleARN=arn:aws:iam::123456789012:role/my-auto-scaling-role &Version=2011-01-01 &AUTHPARAMS

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: