Very simple system load monitor.

load.py

#!/usr/bin/env python
# load.py
# Test the current load of this system and report through e-mail when it's
# above a given threshold.
#
# Koen Bollen <meneer@koenbollen.nl>
# GPLv2 2011
#

LOAD_THRESHOLD = 0.8 # normalized (load/cpus > LOAD_THRESHOLD)

TARGET = "Your Name <you@example.com>"
FROM = "load.py <system@example.com>"
SMTPSERVER = "smtp.example.com"


from email.mime.text import MIMEText
import multiprocessing
import os
import smtplib

def trigger_alarm(load=None):

    if load is None:
        load = getload()
    host = os.uname()[1]

    msg = MIMEText( """***Warning!***

    The load on the system {host} is extremely high!
    Current load: {load}

    Take action!

    Sincerely,
    load.py
    """.format(**locals()) )

    msg['Subject'] = "[load.py] {load}@{host}".format(**locals())
    msg['From'] = FROM
    msg['To'] = TARGET

    s = smtplib.SMTP( SMTPSERVER )
    s.sendmail( FROM, [TARGET], msg.as_string() )
    s.quit()

def getload( procloadavg="/proc/loadavg" ):
    with open( procloadavg ) as fp:
        return max( map(float, fp.readline().split()[:3]) )

def main():
    cpus = multiprocessing.cpu_count()
    load = getload()
    if load/cpus > LOAD_THRESHOLD:
        trigger_alarm(load)

if __name__ == "__main__":
    main()

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