python script which observes networked Wake on Lan calls and forwards them.

wol-observer.txt

-------------| Install deps
sudo apt install etherwake
pip3 install scapy

-------------| Allow unprivileged etherwake invocations
sudo ln -s /usr/sbin/etherwake /usr/bin/etherwake
sudo setcap cap_net_raw+ep /usr/sbin/etherwake

-------------| Get mac address
sudo iwconfig
OR
ip addr show
OR
sudo arp --verbose

-------------| Create:
from scapy.all import *

mac_address = "<< MAC ADDRESS HERE >>"
command = f"etherwake -i eth0 {mac_address}"

def wake_on_lan(packet):
  # NOTE: This doesn't do any validation of the packet (e.g not verifying it's a magic packet),
  #       which is fine as this is on a private tailscale network, but might not be okay for all
  #       use cases.
  print("received wake_on_lan packet", packet)

  try:
    subprocess.run(command, shell=True, check=True)
    print(f"wol signal sent to {mac_address}")
  except subprocess.CalledProcessError as e:
    print(f"subprocess failed. error: {e}")

sniff(prn=wake_on_lan, filter="udp and port 9", store=0)

-------------| Execute:
sudo -E python3 wol.py

-E preserves the caller environment which is required as pip dependencies shouldn't be called from elevated contexts