configure_dhcp_with_netbox.py

#!/usr/bin/env python3

"""
About this script:
1. Get the information on site subnet,
2. reserve new pool for site dhcp server
3. Configure router as dhcp server
The script is run from the environment where NSO is installed
"""

import ncs
import requests
import json

device_name = "router1-ams"

site = device_name.split("-")[1]
pool_name = site + "-office-dhcp"


netbox = "http://10.147.40.80:8000/api/"
token = "0123456789abcdef0123456789abcdef01234567"
headers = {
    'Authorization': 'Token ' + token,
    'Content-Type': 'application/json'
}


def get_subnet():
    url = netbox + "ipam/prefixes/?site=" + site
    response = requests.request("GET", url, headers=headers, data={}).json()
    subnet = response["results"][0]["prefix"]
    return subnet


def reserve_dhcp_pool(subnet):
    start_address = subnet.replace(".0/24", ".129/24")
    end_address = subnet.replace(".0/24", ".254/24")

    url = netbox + "ipam/ip-ranges/"
    payload = json.dumps({
        "start_address": start_address,
        "end_address": end_address,
        "description": pool_name
    })
    response = requests.request("POST", url, headers=headers, data=payload)
    return response


def configure_device(subnet):
    with ncs.maapi.single_write_trans('admin', 'python', groups=['ncsadmin']) as t:
        network_number = subnet.replace(".0/24", ".128")
        default_router = subnet.replace(".0/24", ".1")

        root = ncs.maagic.get_root(t)
        device_cdb = root.devices.device[device_name]
        device_cdb.config.ios__ip.dhcp.pool.create(pool_name)
        device_cdb.config.ios__ip.dhcp.pool[pool_name].default_router.create(default_router)
        device_cdb.config.ios__ip.dhcp.pool[pool_name].network.network_number = network_number
        device_cdb.config.ios__ip.dhcp.pool[pool_name].network.mask = "255.255.255.128"
        params = t.get_params()
        params.dry_run_native()
        result = t.apply_params(True, params)
        print(result['device'][device_name])
        t.apply_params(True, t.get_params())


def main():
    subnet = get_subnet()
    reserve_dhcp_pool(subnet)
    configure_device(subnet)


if __name__ == "__main__":
    main()