Automatic Tags For All EKS Nodes On AWS Account Using Lambda, EventBridge, And CloudTrail

Managing AWS resources efficiently often requires proper tagging, especially for cost allocation and resource tracking. However, manually tagging resources can be error-prone and time-consuming. This article explores how to automate tagging for Elastic Kubernetes Service (EKS) worker nodes using AWS Lambda, EventBridge, and CloudTrail.

How It Works

CloudTrail Logs API Activity – AWS CloudTrail captures all API calls, including EKS node creation.
EventBridge Rule Triggers on Events – An EventBridge rule detects when new EKS nodes are launched.
Lambda Function Applies Tags – A Lambda function processes the event and applies predefined tags automatically.

You Should Know: Practical Implementation

1. Set Up CloudTrail

Ensure CloudTrail is enabled in your AWS account to log management events:

aws cloudtrail create-trail --name AutoTagTrail --s3-bucket-name YOUR_BUCKET_NAME --is-multi-region-trail

2. Create an EventBridge Rule

Define a rule to trigger when an EKS node is created:

{
"source": ["aws.eks"],
"detail-type": ["AWS API Call via CloudTrail"],
"detail": {
"eventSource": ["eks.amazonaws.com"],
"eventName": ["CreateNodegroup"]
}
}

3. Deploy the Lambda Function

Use Python to apply tags dynamically:

import boto3

def lambda_handler(event, context):
eks = boto3.client('eks')
resource_arn = event['detail']['responseElements']['nodegroup']['nodegroupArn']

tags = {
'Environment': 'Production',
'CostCenter': 'DevOps',
'ManagedBy': 'Automation'
}

eks.tag_resource(resourceArn=resource_arn, tags=tags)
return {"status": "Tags applied successfully"}

4. Test & Monitor

Verify the automation by creating an EKS node group and checking tags:

aws eks list-nodegroups --cluster-name YOUR_CLUSTER
aws eks describe-nodegroup --cluster-name YOUR_CLUSTER --nodegroup-name YOUR_NODEGROUP

What Undercode Say

Automating AWS resource tagging ensures consistency and reduces manual effort. This approach can be extended to other AWS services like EC2, RDS, or S3. Key takeaways:
– CloudTrail is essential for tracking AWS API activity.
– EventBridge enables real-time event-driven automation.
– Lambda provides serverless flexibility for custom tagging logic.