Prepare to add a lifecycle hook to your Auto Scaling group

Create a Lambda function by using the Lambda console and note its Amazon Resource Name (ARN). For example, arn:aws-cn:lambda:region:123456789012:function:my-function. You need the ARN to create an EventBridge target. For more information, see Getting started with Lambda in the Amazon Lambda Developer Guide.

To create a rule that matches events for instance launch, use the following put-rule command.

aws events put-rule --name my-rule --event-pattern file://pattern.json --state ENABLED

The following example shows the pattern.json for an instance launch lifecycle action. Replace the text in italics with the name of your Auto Scaling group.

{
  "source": [ "aws.autoscaling" ],
  "detail-type": [ "EC2 Instance-launch Lifecycle Action" ],
  "detail": {
      "AutoScalingGroupName": [ "my-asg" ]
   }
}

If the command runs successfully, EventBridge responds with the ARN of the rule. Note this ARN. You'll need to enter it in step 4.

To create a rule that matches for other events, modify the event pattern. For more information, see Use EventBridge to handle Auto Scaling events.

To specify the Lambda function to use as a target for the rule, use the following put-targets command.

aws events put-targets --rule my-rule --targets Id=1,Arn=arn:aws-cn:lambda:region:123456789012:function:my-function

In the preceding command, my-rule is the name that you specified for the rule in step 2, and the value for the Arn parameter is the ARN of the function that you created in step 1.

To add permissions that allow the rule to invoke your Lambda function, use the following Lambda add-permission command. This command trusts the EventBridge service principal (events.amazonaws.com) and scopes permissions to the specified rule.

aws lambda add-permission --function-name my-function --statement-id my-unique-id \
  --action 'lambda:InvokeFunction' --principal events.amazonaws.com --source-arn arn:aws-cn:events:region:123456789012:rule/my-rule

In the preceding command:

If the command runs successfully, you receive output similar to the following.

{
  "Statement": "{\"Sid\":\"my-unique-id\",
    \"Effect\":\"Allow\",
    \"Principal\":{\"Service\":\"events.amazonaws.com\"},
    \"Action\":\"lambda:InvokeFunction\",
    \"Resource\":\"arn:aws-cn:lambda:us-west-2:123456789012:function:my-function\",
    \"Condition\":
      {\"ArnLike\":
        {\"AWS:SourceArn\":
         \"arn:aws-cn:events:us-west-2:123456789012:rule/my-rule\"}}}"
}

The Statement value is a JSON string version of the statement that was added to the Lambda function policy.

After you have followed these instructions, continue on to Add lifecycle hooks as a next step.

Create an Amazon SNS topic by using either the Amazon SNS console or the following create-topic command. Ensure that the topic is in the same Region as the Auto Scaling group that you're using. For more information, see Getting started with Amazon SNS in the Amazon Simple Notification Service Developer Guide.

aws sns create-topic --name my-sns-topic

Note the topic Amazon Resource Name (ARN), for example, arn:aws-cn:sns:region:123456789012:my-sns-topic. You need it to create the lifecycle hook.

Create an IAM service role to give Amazon EC2 Auto Scaling access to your Amazon SNS notification target.

To give Amazon EC2 Auto Scaling access to your SNS topic

1. Open the IAM console at https://console.amazonaws.cn/iam/.

2. In the navigation pane on the left, choose Roles.

3. Choose Create role.

4. For Select trusted entity, choose Amazon service.

5. For your use case, under Use cases for other Amazon services, choose EC2 Auto Scaling and then EC2 Auto Scaling Notification Access.

6. Choose Next twice to go to the Name, review, and create page.

7. For Role name, enter a name for the role (for example, my-notification-role) and choose Create role.

8. On the Roles page, choose the role that you just created to open the Summary page. Make a note of the role ARN. For example, arn:aws-cn:iam::123456789012:role/my-notification-role. You need it to create the lifecycle hook.

After you have followed these instructions, continue on to Add lifecycle hooks (Amazon CLI) as a next step.

Create an Amazon SQS queue by using the Amazon SQS console. Ensure that the queue is in the same Region as the Auto Scaling group that you're using. For more information, see Getting started with Amazon SQS in the Amazon Simple Queue Service Developer Guide.

Note the queue ARN, for example, arn:aws-cn:sqs:us-west-2:123456789012:my-sqs-queue. You need it to create the lifecycle hook.

Create an IAM service role to give Amazon EC2 Auto Scaling access to your Amazon SQS notification target.

To give Amazon EC2 Auto Scaling access to your SQS queue

1. Open the IAM console at https://console.amazonaws.cn/iam/.

2. In the navigation pane on the left, choose Roles.

3. Choose Create role.

4. For Select trusted entity, choose Amazon service.

5. For your use case, under Use cases for other Amazon services, choose EC2 Auto Scaling and then EC2 Auto Scaling Notification Access.

6. Choose Next twice to go to the Name, review, and create page.

7. For Role name, enter a name for the role (for example, my-notification-role) and choose Create role.

8. On the Roles page, choose the role that you just created to open the Summary page. Make a note of the role ARN. For example, arn:aws-cn:iam::123456789012:role/my-notification-role. You need it to create the lifecycle hook.

After you have followed these instructions, continue on to Add lifecycle hooks (Amazon CLI) as a next step.