Labda function to shut down EC2 instances with a given tag

lambda_function.py

import boto3

region = 'eu-central-1'
testing_vpc_id = 'vpc-2352384b'

client = boto3.client('ec2', region_name=region)


def get_instances_in_vpc(vpc_id):
    response = client.describe_instances(Filters=[{'Name': 'vpc-id',
            'Values': [vpc_id]}])
    return response['Reservations']


def get_stopped_instances_in_vpc(reservations):
    instance_to_be_stopped = []
    for reservation in reservations:
        for instance in reservation['Instances']:
            if instance['State']['Name'] == 'running':
                for running_instance in instance['Tags']:
                    if(running_instance['Key'] == 'environment' and running_instance['Value'] == 'testing'):
                        instance_to_be_stopped.append(instance['InstanceId'])
    return instance_to_be_stopped

def lambda_handler(event, context):
    reservations_in_vpc = get_instances_in_vpc(testing_vpc_id)
    instances_to_stop = get_stopped_instances_in_vpc(reservations_in_vpc)
    client.stop_instances(
        DryRun=False,
        InstanceIds=instances_to_stop
    )
    print 'Stopped Instances: ' + str(instances_to_stop)