Events are not generated for App Load balancer scale up/down

Question

I am looking to automate the workflow of creating "Traffic Mirror Session" with source as App Load Balancer ELB interface when whenever new ELB instance created by AWS.

The Eventbridge is not showing any events for App LB scale up/down or when aws creates new instances though all the events in the account is enabled for the event bus.

Please suggest how to receive events when new ELB instances or new App LB ELB interface created by AWS.

Accepted Answer

Thanks for the clear description.

As you may already know, there's no specific ALB event when ALB scales up/down. However, when ALB scales, we will see changes in terms of network interfaces. We could therefore monitor the following event pattern (leveraging CloudTrail events) for potential automation:

// monitor all ELB calls for interface changes

```
{
  "source": ["aws.ec2"],
  "detail-type": ["AWS API Call via CloudTrail"],
  "detail": {
    "eventSource": ["ec2.amazonaws.com"],
    "eventName": ["CreateNetworkInterface", "DeleteNetworkInterface"],
    "userAgent": ["elasticloadbalancing.amazonaws.com"]
  }
}
```

// or monitor all calls from specific ELB for interface changes

```
{
  "source": ["aws.ec2"],
  "detail-type": ["AWS API Call via CloudTrail"],
  "detail": {
    "eventSource": ["ec2.amazonaws.com"],
    "eventName": ["CreateNetworkInterface", "DeleteNetworkInterface"],
    "requestParameters": {
      "description": ["ELB app/alb_name/dbe23be94aa68888"]
    }
  }
}
```

Events are not generated for App Load balancer scale up/down

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