Help Center> Auto Scaling> API Reference> APIs> Lifecycle Hooks> Creating a Lifecycle Hook

Updated on 2023-07-06 GMT+08:00

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Creating a Lifecycle Hook

Function

This interface is used to create a lifecycle hook for an AS group. Up to five lifecycle hooks can be created for one AS group.

After the creation, when the AS group performs a scaling action, the lifecycle hook suspends the target instance and sets it to be in Wait (Adding to AS group) or Wait (Removing from AS group) status. This status retains until the timeout duration expires or you manually call back this status.
During the instance waiting duration, you can perform customized operations. For example, you can install or configure software on a newly started instance, or download the log file from the instance before the instance terminates.

URI

POST /autoscaling-api/v1/{project_id}/scaling_lifecycle_hook/{scaling_group_id}

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
project_id	Yes	String	Specifies the project ID.
scaling_group_id	Yes	String	Specifies the AS group ID.

Request

**Table 2** Request parameters
Parameter	Mandatory	Type	Description
lifecycle_hook_name	Yes	String	Specifies the lifecycle hook name. The name contains only letters, digits, underscores (_), and hyphens (-), and cannot exceed 32 characters.
lifecycle_hook_type	Yes	String	Specifies the lifecycle hook type. Options: INSTANCE_TERMINATING: The hook suspends the instance when the instance is terminated. INSTANCE_LAUNCHING: The hook suspends the instance when the instance is started.
default_result	No	String	Specifies the default lifecycle hook callback operation. By default, this operation is performed when the timeout duration expires. ABANDON CONTINUE NOTE: If an instance is starting, CONTINUE indicates that your customized operations are successful and the instance can be used. ABANDON indicates that your customized operations failed, and the instance will be terminated. In such a case, the scaling action fails, and you must create a new instance. If an instance is stopping, both ABANDON and CONTINUE allow instance termination. The difference between the two states is as follows: ABANDON stops other lifecycle hooks, but CONTINUE allows the completion of other lifecycle hooks. The default value of this parameter is ABANDON.
default_timeout	No	Integer	Specifies the lifecycle hook timeout duration, which ranges from 60 to 86400 in the unit of second. The default value is 3600. By default, this parameter specifies the instance waiting duration. You can prolong the timeout duration or perform the CONTINUE or ABANDON operation before the timeout duration expires.
notification_topic_urn	Yes	String	Specifies a unique topic in SMN. This parameter specifies a notification object for a lifecycle hook. When an instance is suspended by the lifecycle hook, the SMN service sends a notification to the object. This notification contains the basic instance information, your customized notification content, and the token for controlling lifecycle operations.
notification_metadata	No	String	Specifies a customized notification, which contains no more than 256 characters in length. The message cannot contain the following characters: <>&'() After a notification object is configured, the SMN service sends your customized notification to the object.

Example Request

This example creates a lifecycle hook named test-hook1 in the AS group with ID e5d27f5c-dd76-4a61-b4bc-a67c5686719a. The configuration is as follows: The callback operation is ABANDON, the timeout duration is 3600 seconds; the notification topic_urn is urn:smn:regionId:b53e5554fad0494d96206fb84296510b:gsh, the hook suspends the instance when the instance is started.

POST https://{Endpoint}/autoscaling-api/v1/{project_id}/scaling_lifecycle_hook/e5d27f5c-dd76-4a61-b4bc-a67c5686719a

{
    "lifecycle_hook_name": "test-hook1",
    "default_result": "ABANDON",
    "default_timeout": 3600,
    "notification_topic_urn": "urn:smn:regionId:b53e5554fad0494d96206fb84296510b:gsh",
    "lifecycle_hook_type": "INSTANCE_LAUNCHING"
}

Response

**Table 3** Response parameters
Parameter	Type	Description
lifecycle_hook_name	String	Specifies the lifecycle hook name.
lifecycle_hook_type	String	Specifies the lifecycle hook type. INSTANCE_TERMINATING INSTANCE_LAUNCHING
default_result	String	Specifies the default lifecycle hook callback operation. ABANDON CONTINUE
default_timeout	Integer	Specifies the lifecycle hook timeout duration in the unit of second.
notification_topic_urn	String	Specifies a unique topic in SMN.
notification_topic_name	String	Specifies the topic name in SMN.
notification_metadata	String	Specifies the notification message.
create_time	String	Specifies the UTC-compliant time when the lifecycle hook is created.

Example Response

{
    "lifecycle_hook_name": "test-hook1",
    "default_result": "ABANDON",
    "default_timeout": 3600,
    "notification_topic_urn": "urn:smn:regionId:b53e5554fad0494d96206fb84296510b:gsh",
    "notification_topic_name": "gsh",
    "lifecycle_hook_type": "INSTANCE_LAUNCHING",
    "notification_metadata": null,
    "create_time": "2019-03-18T16:00:11Z"
}

Returned Values

Normal
200

Abnormal

Returned Value	Description
400 Bad Request	The server failed to process the request.
401 Unauthorized	You must enter the username and password to access the requested page.
403 Forbidden	You are forbidden to access the requested page.
404 Not Found	The server could not find the requested page.
405 Method Not Allowed	You are not allowed to use the method specified in the request.
406 Not Acceptable	The response generated by the server could not be accepted by the client.
407 Proxy Authentication Required	You must use the proxy server for authentication to process the request.
408 Request Timeout	The request timed out.
409 Conflict	The request could not be processed due to a conflict.
500 Internal Server Error	Failed to complete the request because of an internal service error.
501 Not Implemented	Failed to complete the request because the server does not support the requested function.
502 Bad Gateway	Failed to complete the request because the request is invalid.
503 Service Unavailable	Failed to complete the request because the system is unavailable.
504 Gateway Timeout	A gateway timeout error occurred.