Auto Scaling:Automate the addition or removal of the private IP addresses of ECS instances to or from the IP address whitelist of a Redis instance

Create the permission policy

1. Log on to the RAM console.

2. In the left-side navigation pane, choose Permissions > Policies.

3. Click Create Policy.

4. On the Create Policy page, click the JSON tab and enter the following policy document:

   {
       "Version": "1",
       "Statement": [
           {
               "Action": [
                   "ecs:DescribeInstances"
               ],
               "Resource": "*",
               "Effect": "Allow"
           },
           {
               "Action": [
                   "kvstore:ModifySecurityIps"
               ],
               "Resource": "*",
               "Effect": "Allow"
           },
           {
               "Action": [
                   "ess:CompleteLifecycleAction"
               ],
               "Resource": "*",
               "Effect": "Allow"
           }
       ]
   }

5. Set Name to ESSHookPolicyForRedisWhitelist and click OK.

Attach the policy to OOSServiceRole

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

2. Find the OOSServiceRole RAM role and click Grant Permission in the Actions column.

3. In the Grant Permission panel, set Resource Scope to Account and select the ESSHookPolicyForRedisWhitelist custom policy.

4. Click Grant permissions.

Create the lifecycle hook

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 your scaling group is located.

4. Find the scaling group and click its ID in the Scaling Group Name/ID column, or click Details in the Actions column.

5. Click the Lifecycle Hook tab, then click Create Lifecycle Hook.

6. Configure the following parameters and click OK:

   Parameter	Value
   Name	ESSHookForAddRedisWhitelist
   Scaling Activity	Scale-out Event
   Timeout Period	300 (seconds). Configure this parameter based on your business requirements. We recommend that you estimate the period of time required to perform custom operations on instances and set this value accordingly. If the timeout period is shorter than the actual execution time, the O&M tasks may fail.
   Default Execution Policy	Continue
   Send Notification When Lifecycle Hook Takes Effect	Select OOS Template > Public Templates > ACS-ESS-LifeCycleModifyRedisIPWhitelist

7. In the ACS-ESS-LifeCycleModifyRedisIPWhitelist template, configure the following parameters:

   Parameter	Value
   dbInstanceId	The ID of the Tair instance
   modifyMode	Append — adds the private IP address to the whitelist during scale-out
   OOSAssumeRole	OOSServiceRole

Lifecycle hooks do not take effect when you manually add or remove ECS instances to or from a scaling group. They only fire during automated scaling events triggered by scaling rules, scheduled tasks, or event-triggered tasks.

Trigger a scale-out event

Create and execute a scaling rule to trigger the lifecycle hook.

1. Click the Scaling Rules and Event-triggered Tasks tab.

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

3. Configure the following parameters and click OK:

   Parameter	Value
   Rule Name	Add1
   Rule Type	Simple Scaling Rule
   Operation	Add 1 Instances

4. Find the Add1 scaling rule and click Execute in the Actions column.

5. In the Execute Scaling Rule dialog box, click OK.

After the rule executes, Auto Scaling adds one ECS instance to the scaling group. The instance enters the Pending Add state while the lifecycle hook is active. During the timeout period, Auto Scaling notifies OOS to run the O&M tasks defined in the ACS-ESS-LifeCycleModifyRedisIPWhitelist template.