code-dumps/aws/lambda-ec2StartStop.py

# reference: https://aws.amazon.com/premiumsupport/knowledge-center/start-stop-lambda-eventbridge/
import boto3
import os
import json
import time
import logging

logging.basicConfig(
    format='%(asctime)s %(levelname)-8s %(message)s',
    level=logging.INFO,
    datefmt='%Y-%m-%d %H:%M:%S')
logger = logging.getLogger(__name__)


def start_instances(instances: list[str]) -> dict:
    ec2 = boto3.client('ec2', region_name=os.environ['AWS_REGION'])
    resp = ec2.start_instances(InstanceIds=instances)
    ec2.close()
    return resp


def stop_instances(instances: list[str]) -> dict:
    ec2 = boto3.client('ec2', region_name=os.environ['AWS_REGION'])
    resp = ec2.stop_instances(InstanceIds=instances)
    ec2.close()
    return resp


def instance_status(instances: list[str]) -> str:
    time.sleep(10)
    ec2 = boto3.client('ec2', region_name=os.environ['AWS_REGION'])
    ec2Array: list[dict] = []
    response = ec2.describe_instances(InstanceIds=instances)
    for r in response['Reservations']:
        for i in r['Instances']:
            for t in i['Tags']:
                if t['Key'] == 'Name':
                    ec2Array.append({'id': i['InstanceId'], 'name': t['Value'], 'state': i['State']['Name']})
    ec2.close()
    return json.dumps(ec2Array)


def lambda_handler(event, context):
    instances: list[str] = json.loads(os.environ['instances'])
    if event['action'] == 'start':
        logger.info('Starting instances: ' + str(instances))
        resp = start_instances(instances)
        logger.info(instance_status(instances))
    elif event['action'] == 'stop':
        logger.info('Stopping instances: ' + str(instances))
        resp = stop_instances(instances)
        logger.info(instance_status(instances))
    else:
        resp = "Event action not provided"
    return resp