Proof of concept: handle TERM signal but finish a job if it's already started

closer.py

#!/usr/bin/python -u
# closer.py
#
# Just a trivial demo that handlers a TERM signal to exit cleanly, while still finishing
# any job that could have been running.

import signal
import sys
import time


JOB_COUNT = 0 
STOP_FLAG = False


def stop(signum, stack):
    """Doesn't really stop now: just set a mark.
    """
    global STOP_FLAG

    STOP_FLAG = True


# Call function stop() when killed.
signal.signal(signal.SIGTERM, stop)




def get_job():
    """Just a dirty counter, returns incremental job ids.
    """
    global JOB_COUNT
    JOB_COUNT += 1 
    return JOB_COUNT


def do_job(job_id):
    """Run your job here.
    """
    print "Job #{} started".format(job_id),
    for i in range(20):
        print '.',
        time.sleep(.1)
    print "Job #{} finished".format(job_id)
    return



while True:
    if STOP_FLAG:
        # Don't take more jobs, just exit.
        sys.exit(0)
    else:
        # Process another job.
        job_id = get_job()
        do_job(job_id)