ha-nat-eip

#!/usr/bin/python
# coding: UTF-8

import boto
import boto.ec2
import boto.vpc
from boto.utils import get_instance_metadata

import argparse
import os
import sys
import time


def main():
    try:
        ec2_conn = boto.ec2.connect_to_region(args.region,aws_access_key_id=args.aws_access_key_id,aws_secret_access_key=args.aws_secret_access_key,profile_name=args.profile)
        vpc_conn = boto.vpc.connect_to_region(args.region,aws_access_key_id=args.aws_access_key_id,aws_secret_access_key=args.aws_secret_access_key,profile_name=args.profile)
    except:
        print "UNKNOWN: Unable to connect to reqion %s" %(args.region)
        sys.exit(1)

    change_privateip(vpc_conn)
    change_eip(ec2_conn)
    sys.exit(0)

def change_privateip(vpc_conn):
    try:
        rt = vpc_conn.get_all_route_tables(filters={'tag:Name':args.routetable})[0]
    except:
        print "UNKNOWN: Was not found %s" %(args.routetable)
        sys.exit(1)

    has_default_route = False

    for route in rt.routes:
        if route.destination_cidr_block == args.network:
            has_default_route = True

    if has_default_route:
        vpc_conn.replace_route(
                route_table_id=rt.id,
                destination_cidr_block=args.network,
                instance_id=get_instance_metadata()['instance-id'])
    else:
        vpc_conn.create_route(
                route_table_id=rt.id,
                destination_cidr_block=args.network,
                instance_id=get_instance_metadata()['instance-id'])

    try:
        rt = vpc_conn.get_all_route_tables(filters={'tag:Name':args.routetable})[0]
    except:
        print "UNKNOWN: Was not found %s" %(args.routetable)
        sys.exit(1)

    has_default_route = False

    for route in rt.routes:
        if route.destination_cidr_block == args.network:
            has_default_route = True
            prt=route

    if has_default_route:
        print "%s cidr:%s gateway:%s" %(time.strftime("%c"),prt.destination_cidr_block,prt.instance_id)
    else:
        print "ERROR: Route is not registered %s" %(args.network)
        sys.exit(1)

def change_eip(ec2_conn):

    eip=ec2_conn.get_all_addresses(allocation_ids=args.allocation_id)[0]

    try:
        ec2_conn.disassociate_address(eip.public_ip)
    except:
        print "ERROR: Allocation-id is not registered %s" %(args.allocation_id)
        sys.exit(1)

    try:
        ec2_conn.associate_address(instance_id=get_instance_metadata()['instance-id'],
                                    allocation_id=args.allocation_id)
    except:
        print "ERROR: Registration error of ElasticIP %s" %(args.allocation_id)
        sys.exit(1)

    print "%s InstanceID:%s EIP:%s" %(time.strftime("%c"),eip.instance_id,eip.public_ip)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Instance Start Stop')

    parser.add_argument('-a', '--aws-access-key-id', required=False, dest='aws_access_key_id', help='AWS Access Key')
    parser.add_argument('-s', '--aws-secret-access-key', required=False, dest='aws_secret_access_key', help='AWS Secret Access Key')
    parser.add_argument('--profile', required=False, dest='profile', help=' Profile name of AWS shared credential file entry.')
    parser.add_argument('-r', '--region', required=True, dest='region', help='AWS Region')
    parser.add_argument('-n', '--name', required=False, dest='tagname', help='Name_Tag')
    parser.add_argument('-f', '--filename', required=False, dest='filename', help='List File')
    parser.add_argument('-R', '--route-table', required=True, dest='routetable', help='AWS Route Table Name')
    parser.add_argument('-N', '--network', required=True, dest='network', help='AWS Network Address')
    parser.add_argument('-E', '--allocation-id', required=True, dest='allocation_id', help='AWS EIP Allocation ID')

    args = parser.parse_args()

    main()