AWS Lambda for AMI and Snapshot Age Monitoring-Python

Introduction

In this blog post, we’ll explore an AWS Lambda function designed to monitor the age of Amazon Machine Images (AMIs), EBS snapshots, and RDS snapshots in your AWS environment. This script checks for resources older than a specified threshold, providing insights into potential cleanup or rotation actions.

Prerequisites

Before we dive into the Lambda function, make sure you have the following:

• AWS account with the necessary permissions to describe EC2 images, snapshots, and RDS snapshots.
• AWS Lambda configured with an execution role that has permissions to interact with EC2 and RDS services.

The Lambda Function

import json
import boto3
from datetime import datetime, timedelta, timezone

import json
import os
import boto3
from datetime import datetime, timedelta, timezone

def lambda_handler(event, context):
Ami = []
Snapshot = []
n_days_threshold = int(os.environ['days'])

utc_timezone = timezone.utc

ec2 = boto3.client('ec2')
rds = boto3.client('rds')

current_time = datetime.now(utc_timezone)

# Include EC2 AMIs
amis = ec2.describe_images(Owners=['self'])['Images']

for ami in amis:
creation_time = ami['CreationDate']
creation_datetime = datetime.strptime(creation_time, "%Y-%m-%dT%H:%M:%S.%fZ").replace(tzinfo=utc_timezone)
age = current_time - creation_datetime

if age.days > n_days_threshold:
print(f"EC2 AMI {ami['ImageId']} created more than {n_days_threshold} days ago.")
Ami.append({'ImageId': ami['ImageId']})

# Include EC2 snapshots
snapshots = ec2.describe_snapshots(OwnerIds=['self'])['Snapshots']

for snapshot in snapshots:
start_time = snapshot['StartTime'].astimezone(utc_timezone)
age = current_time - start_time

if age.days > n_days_threshold:
print(f"EC2 Snapshot ID: {snapshot['SnapshotId']} is older than {n_days_threshold} days.")
print(f"Snapshot Start Time: {start_time}")
Snapshot.append({'snapshot': snapshot['SnapshotId']})

# Include RDS snapshots
rds_snapshots = rds.describe_db_snapshots()['DBSnapshots']

for rds_snapshot in rds_snapshots:
snapshot_time = rds_snapshot['SnapshotCreateTime']
snapshot_datetime = snapshot_time.replace(tzinfo=utc_timezone)
age = current_time - snapshot_datetime

if age.days > n_days_threshold:
print(f"RDS Snapshot ID: {rds_snapshot['DBSnapshotIdentifier']} is older than {n_days_threshold} days.")
print(f"RDS Snapshot Create Time: {snapshot_datetime}")
Snapshot.append({'snapshot': rds_snapshot['DBSnapshotIdentifier']})

# Correct the message generation part
message = f"EC2 AMI {'/'.join(item['ImageId'] for item in Ami)} created more than {n_days_threshold} days ago.\n"
message += f"EC2 Snapshot ID: {'/'.join(item['snapshot'] for item in Snapshot)} is older than {n_days_threshold} days."

print(message)

# You can further modify the function based on your use case, e.g., sending notifications, deleting snapshots, etc.

return {
'statusCode': 200,
'body': json.dumps('Function executed successfully!')
}

How to Deploy and Test

Create a Lambda Function:

• Open the AWS Lambda console.
• Click “Create function.”
• Choose “Author from scratch.”
• Configure the basic settings and create a new execution role with EC2 and RDS permissions.

Copy and Paste Code:

• In the Lambda function code editor, replace the existing code with the provided Python script.

Adjust Configurations:

• Modify the n_days_threshold variable to set your desired threshold for resource age.

Test the Lambda Function:

• Save the Lambda function.
• Manually test the Lambda function to observe its output in the AWS CloudWatch Logs.

Conclusion

This AWS Lambda function provides a powerful solution for monitoring the age of AMIs, snapshots, and RDS snapshots in your AWS environment. By customizing the script based on your specific requirements and scheduling it to run periodically, you can ensure that outdated resources are regularly identified and cleaned up.

Feel free to integrate additional features or notifications to suit your needs. AWS Lambda offers a scalable solution for automating tasks and responding to events within your AWS environment.

Optimize your AWS costs! This Lambda function monitors AMIs, snapshots, and RDS snapshots, identifying potentially outdated resources. Schedule it to run regularly and automate cleanup, saving you storage costs.