infrastructure-provisioning/src/general/scripts/azure/common_create_subnet.py

#!/usr/bin/python

# *****************************************************************************
#
# Copyright (c) 2016, EPAM SYSTEMS INC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# ******************************************************************************

import argparse
import json
from dlab.actions_lib import *
from dlab.meta_lib import *
import sys
import ipaddress


parser = argparse.ArgumentParser()
parser.add_argument('--resource_group_name', type=str, default='')
parser.add_argument('--subnet_name', type=str, default='')
parser.add_argument('--region', type=str, default='')
parser.add_argument('--vpc_name', type=str, default='')
parser.add_argument('--prefix', type=str, default='')
parser.add_argument('--vpc_cidr', type=str, default='')
args = parser.parse_args()


if __name__ == "__main__":
    empty_vpc = False
    private_subnet_size = ipaddress.ip_network(u'0.0.0.0/{}'.format(args.prefix)).num_addresses
    first_vpc_ip = int(ipaddress.IPv4Address(args.vpc_cidr.split('/')[0].decode("utf-8")))
    subnets_cidr = []
    subnets = AzureMeta().list_subnets(args.resource_group_name, args.vpc_name)
    for subnet in subnets:
        subnets_cidr.append(subnet.address_prefix)
    sorted_subnets_cidr = sorted(subnets_cidr)
    if not subnets_cidr:
        empty_vpc = True

    last_ip = first_vpc_ip
    for cidr in sorted_subnets_cidr:
        first_ip = int(ipaddress.IPv4Address(cidr.split('/')[0].decode("utf-8")))
        if first_ip - last_ip < private_subnet_size:
            subnet_size = ipaddress.ip_network(u'{}'.format(cidr)).num_addresses
            last_ip = first_ip + subnet_size - 1
        else:
            break
    if empty_vpc:
        dlab_subnet_cidr = '{0}/{1}'.format(ipaddress.ip_address(last_ip), args.prefix)
    else:
        dlab_subnet_cidr = '{0}/{1}'.format(ipaddress.ip_address(last_ip + 1), args.prefix)
    if args.subnet_name != '':
        if AzureMeta().get_subnet(args.resource_group_name, args.vpc_name, args.subnet_name):
            print("REQUESTED SUBNET {} ALREADY EXISTS".format(args.subnet_name))
        else:
            print("Creating Subnet {}".format(args.subnet_name))
            AzureActions().create_subnet(args.resource_group_name, args.vpc_name, args.subnet_name, dlab_subnet_cidr)
    else:
        sys.exit(1)