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Print out "creation time" for EC2 instances (in reality, it's the first network interface attachement time)
import boto3
import datetime
# iterator over EC2 instances for region
def ec2_instances(region):
client = boto3.client('ec2', region_name = region)
for reservation in client.describe_instances().get('Reservations', []):
for instance in reservation.get('Instances', []):
yield instance
# iterator over EC2 regions
def ec2_regions():
for region in boto3.client('ec2').describe_regions().get('Regions', []):
yield region
# Name tag of EC2 instance
def instance_name(instance):
tags = {t['Key']: t['Value'] for t in instance.get('Tags', [])}
return tags.get('Name', 'NONAME')
# AttachTime for EC2 instance primary interface
def net_attach_time(instance):
default_time =
for interface in instance.get('NetworkInterfaces', []):
attachement = interface.get('Attachment', {})
if attachement.get('DeviceIndex') == 0:
return attachement.get('AttachTime', default_time)
return default_time
def lambda_handler(event, context):
for region in (r['RegionName'] for r in ec2_regions()):
for instance in ec2_instances(region):
print(' %s: %s' % (instance_name(instance), net_attach_time(instance)))
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