We would like to know if we are still being billed for ALBs with no current target instance.

Hi kat,

Check for Unused ALBs:

AWS Management Console:

Go to the EC2 Dashboard. Click on "Load Balancers" under "Load Balancing." Look for ALBs with no instances attached.

AWS CLI:

aws elbv2 describe-load-balancers --query 'LoadBalancers[*].[LoadBalancerName, LoadBalancerArn, State.Code]'
aws elbv2 describe-target-groups --load-balancer-arn <your-load-balancer-arn> --query 'TargetGroups[*].TargetGroupArn'
aws elbv2 describe-target-health --target-group-arn <your-target-group-arn> --query 'TargetHealthDescriptions[*].Target'

Delete Unused ALBs:

AWS Management Console:

In the EC2 Dashboard, select the ALB. Click "Actions" and select "Delete."

aws elbv2 delete-load-balancer --load-balancer-arn <your-load-balancer-arn>

Automate Cleanup (Optional):

• AWS Config Rules: Set up rules to detect and notify you about unused ALBs.
• **Lambda Function: **Use a Lambda function to periodically check and delete unused ALBs.

Example Lambda function:

import boto3

client = boto3.client('elbv2')

def lambda_handler(event, context):
    load_balancers = client.describe_load_balancers()
    for lb in load_balancers['LoadBalancers']:
        lb_arn = lb['LoadBalancerArn']
        target_groups = client.describe_target_groups(LoadBalancerArn=lb_arn)
        for tg in target_groups['TargetGroups']:
            tg_arn = tg['TargetGroupArn']
            targets = client.describe_target_health(TargetGroupArn=tg_arn)
            if not targets['TargetHealthDescriptions']:
                print(f"Deleting ALB: {lb['LoadBalancerName']} with no targets")
                client.delete_load_balancer(LoadBalancerArn=lb_arn)
    return {'statusCode': 200, 'body': 'Checked and deleted unused ALBs'}