Updated on 2022-02-22 GMT+08:00

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 Message

  • Request parameters
    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 300 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 shows how to create 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 Message

  • Response parameters
    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 so that the request can be processed.

    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.

Error Codes

See Error Codes.