main.py

import json
import uuid
import os

CURRENT_PATH = os.getcwd()
KEA_DHCP_INPUT_FILE_PATH = os.path.join(CURRENT_PATH, 'config', 'kea_dhcp_input.json')
KEA_DHCP_OUTPUT_FILE_PATH = os.path.join(CURRENT_PATH, 'config', 'kea_dhcp_output.json')
SITE_ID_GUID_MAP_PATH = os.path.join(CURRENT_PATH, 'config', 'fits_id_guid_map.json')

# Define the dhcp option data structure.
option_data = [
    {
        "name": "delivery-optimisation",
        "space": "dhcp4",
        "code": 234,
        "data": "",
    }
]


def main():
    # Open the kea dhcp config fie, load the json into a python dictionary and close the input file.
    kea_config_file = open(KEA_DHCP_INPUT_FILE_PATH, 'r')
    kea_data = json.load(kea_config_file)
    kea_config_file.close()

    # Open the fits id guid map config fie, load the json into a python dictionary and close the input file.
    fits_id_guid_map_file = open(SITE_ID_GUID_MAP_PATH, 'r')
    fits_id_guid_map_data = json.load(fits_id_guid_map_file)
    fits_id_guid_map_file.close()

    # Break out the shared networks element from the kea config.
    shared_nets = kea_data['Dhcp4']['shared-networks']
    # Iterate through the shared networks.
    for shared_net in shared_nets:
        subnets = shared_net['subnet4']
        if not subnets:
            continue
        for subnet in subnets:
            site_id = subnet['user-context']['site-id']
            if site_id not in fits_id_guid_map_data:
                fits_id_guid_map_data[site_id] = str(uuid.uuid4())

            if 'option-data' in subnet:
                continue
            # Populate the option data field with the guid based on the site id.
            option_data[0]['data'] = fits_id_guid_map_data[site_id]
            # Populate the subnet with the option data.
            subnet["option-data"] = option_data

    # Open the file and Write the site_id_map_json data back to a file.
    site_id_map_json = open(SITE_ID_GUID_MAP_PATH, 'w')
    site_id_map_json.write(json.dumps(fits_id_guid_map_data))
    site_id_map_json.close()
    # Open the file and Write the updated kea dhcp config to a new file.
    kea_dhcp_output_file = open(KEA_DHCP_OUTPUT_FILE_PATH, 'w')
    kea_dhcp_output_file.write(json.dumps(kea_data))
    kea_dhcp_output_file.close()


if __name__ == '__main__':
    main()