:Automatically release secondary ENIs that have EIPs for ECS instances

Procedure

In this example, the ACS-ESS-LifeCycleDetachNetworkInterfaceAndDeleteEip public template is used to show how to automate the process of simultaneously releasing secondary ENIs and EIPs for ECS instances.

Step 1: Grant a RAM role the permissions on OOS

You must have the permissions to execute OOS templates. The ACS-ESS-LifeCycleDetachNetworkInterfaceAndDeleteEip template includes ECS, Auto Scaling, and EIP resources that are required to perform O&M tasks.

1. Log on to the RAM console.

2. In the left-side navigation pane, choose Identities > Roles.

3. Find OOSServiceRole and click Grant Permission in the Actions column.

   Add the required permissions for the OOSServiceRole RAM role that is assumed by OOS to complete the authorization.

4. In the Grant Permission panel, configure Resource Scope and Policy. After you complete the configuration, click Grant permissions.

   The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

   Parameter	Description
   Resource Scope	Set the value to Account.
   Policy	Select the following system policies: AliyunECSFullAccess, AliyunESSFullAccess, and AliyunEIPFullAccess.

Step 2: Create a lifecycle hook for scale-in purposes and trigger a scale-in event

1. Log on to the Auto Scaling console.

2. In the left-side navigation pane, click Scaling Groups.

3. In the top navigation bar, select the region where Auto Scaling is activated.

4. Find a scaling group and use one of the following methods to go to the scaling group details page:

   • Click the ID of the scaling group in the Scaling Group Name/ID column.

   • Click Details in the Actions column.

5. Create a lifecycle hook.

   1. In the upper part of the scaling group details page, click the Lifecycle Hook tab.

   2. Click Create Lifecycle Hook.

   3. Configure parameters based on your business requirements and click OK.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Name	Enter ESSHookForDeleteNicAndEip.
      Scaling Activity	Select Scale-in Event.
      Timeout Period	Configure Timeout Period based on your business requirements. In this example, set the value to 300. Unit: seconds. Note The timeout period is the period of time during which you can perform custom operations on instances. If the timeout period is shorter than the period of time that is required to perform custom operations, the operations may fail. We recommend that you estimate the period of time that is required to perform custom operations on instances and configure Timeout Period based on your estimates.
      Default Execution Policy	Select Continue.
      Send Notification When Lifecycle Hook Takes Effect	Configure the following parameters for the template: Select OOS Template. Select Public Templates. Select ACS-ESS-LifeCycleDetachNetworkInterfaceAndDeleteEip. In the ACS-ESS-LifeCycleDetachNetworkInterfaceAndDeleteEip public template, set OOSAssumeRole to OOSServiceRole. In Step 1, OOSServiceRole is granted the permissions on the ECS, Auto Scaling, and EIP resources. OOS obtains the preceding permissions after it assumes the RAM role.

6. Trigger a scale-in event.

   In this example, a scale-in event is manually triggered by executing a scaling rule. You can also trigger scale-in events by using scheduled or event-triggered tasks.

   Note

   If scaling activities are triggered when you manually execute scaling rules, lifecycle hooks take effect. Lifecycle hooks do not take effect when you manually add or remove ECS instances to or from a scaling group.

   1. In the upper part of the page that appears, click the Scaling Rules and Event-triggered Tasks tab.

   2. On the Scaling Rules tab, click Create Scaling Rule.

   3. In the Create Scaling Rule dialog box, configure parameters based on your business requirements and click OK.

      The following table describes the settings that are used in this example. Any parameters not covered in the following table default to their predefined settings.

      Parameter	Description
      Rule Name	Enter Delete1.
      Rule Type	Select Simple Scaling Rule.
      Operation	Set the value to Remove 1 Instances.

   4. On the Scaling Rules tab, find Delete1 and click Execute in the Actions column.

   5. In the Execute Scaling Rule message, click OK.

   After the scaling rule is executed, Auto Scaling removes one ECS instance from the scaling group. However, the ECS instance enters the Pending Remove state because of the ESSHookForDeleteNicAndEip lifecycle hook that is in effect. During the timeout period of the lifecycle hook, Auto Scaling notifies OOS to execute the O&M tasks that are defined in the ACS-ESS-LifeCycleDetachNetworkInterfaceAndDeleteEip public template.

7. Check whether the execution result meets your expectations.

   You can go to the Network Interfaces page to check whether the ENI exists and the Elastic IP Addresses page to check whether the EIP exists. If the ENI and the EIP do not exist, the release is successful.

   If the ECS instance is removed from the scaling group but the ENI or the EIP still exists, you can go to the OOS console to check the execution of the O&M tasks.

Step 3: (Optional) View the OOS execution

1. Log on to the OOS console.

2. In the left-side navigation pane, choose Automated Tasks > Task Execution Management.

3. Find the execution task by time and click Details in the Actions column.

4. On the execution details page that appears, view the related information.

   For example, in the Basic Information section, you can view the execution ID and status. In the Execution Steps and Results section, you can click a task node to view the execution details. For more information, see View the details of an execution.

   Note

   If the execution fails, an error message is displayed on the execution details page.

Common errors and troubleshooting