myservice.py

import time, signal

def exit_gracefully(signum, frame):
    global exit_now
    exit_now = True
    
signal.signal(signal.SIGTERM, exit_gracefully)

filename = "/home/<username>/myprogram/logs/myservice.log"
exit_now = False
with open(filename, "w") as fl:
    while not exit_now:
        fl.write(time.ctime() + '\n')
        time.sleep(1)