Show current DHCP leases for all interfaces when using systemd networkd as DHCP server

dhcp-leases.py

#!/usr/bin/env python3
import json
from os import listdir, path
from datetime import datetime

# this is the default path on Debian-based distros
DHCP_DIR = '/var/lib/systemd/network/dhcp-server-lease'

def main():
    lfiles = [path.join(DHCP_DIR,lf) for lf in listdir(DHCP_DIR)]
    for lfile in lfiles:
        print_file(lfile)

def print_file(lfile):
    # Read the JSON file
    with open(lfile, 'r') as file:
        data = json.load(file)

    # Extract and print the HardwareAddress in hexadecimal
    for lease in data.get('Leases', []):
        address = '.'.join(map(str, lease.get('Address', [])))
        hostname = lease.get('Hostname', 'N/A')[:18]
        expire_usec = lease.get('ExpirationRealtimeUSec', 'N/A') / 1000000
        expiration = datetime.fromtimestamp(expire_usec).strftime('%y-%m-%d %H:%M:%S')
        hardware_address = lease.get('HardwareAddress', [])[:6]
        hex_address = ':'.join(f'{value:02x}' for value in hardware_address)
        print(f"{address}  {hostname:<15} \t {hex_address:<18} \t {expiration}")

if __name__ == '__main__':
    main()