#!/usr/bin/env python3
import boto
import boto.ec2
import boto.utils
import common
import os


class NetworkInterfaceAttachment(object):

    def __init__(self, conn, logger, role, subnet_id, instance_id, device_index=1):
        self.conn = conn
        self.logger = logger
        self.role = role
        self.subnet_id = subnet_id
        self.instance_id = instance_id
        self.device_index = device_index
        self.logger.info(
            "Initializing NetworkInterfaceAttachment {0.role} in subnet {0.subnet_id} to instance {0.instance_id} on index {0.device_index}".format(
                self))

    def __find_network_interface(self):
        return self.conn.get_all_network_interfaces(
            filters={'tag:Role': self.role, 'subnet-id': self.subnet_id}
        )[0]

    def attach(self):
        network_interface = self.__find_network_interface()
        self.logger.info("Attaching Network Interface {0} to {1}".
                         format(network_interface, self.instance_id))
        network_interface.attach(self.instance_id, self.device_index)


def main():
    instance_metadata = boto.utils.get_instance_metadata()
    instance_id = instance_metadata['instance-id']
    subnet_id = list(instance_metadata['network']['interfaces']['macs'].values())[
        0]['subnet-id']

    conn = boto.ec2.connect_to_region(
        boto.utils.get_instance_identity()['document']['region'])
    
    role = common.InstanceTags(ec2_conn, instance_id).get_role()
    
    logger = common.build_logger(
        NetworkInterfaceAttachment.__name__, os.environ['LOGGLY_TOKEN'], [instance_id, role])
    
    try:
        NetworkInterfaceAttachment(
            conn, logger, role, subnet_id, instance_id).attach()
    except:
        logger.exception("Failed to attach network interface.")


if __name__ == '__main__':
    main()

@@ -1454,12 +1454,8 @@
 ags(
-ec2_
 conn

fix ec2_conn -> conn