load-monitoring script that pushes notifications to prowl when something goes wrong

prowl_monitor.py

#!/usr/bin/env python
"""
load-monitoring script that pushes notifications to growl when something goes wrong

requires jacobb's prowlpy http://github.com/jacobb/prowlpy/tree/master - and a prowl
account (http://prowl.weks.net/)

this version, with a "panic" function, is untested.
"""

from __future__ import with_statement #python 2.5 compatibility
from time import sleep
import prowlpy


API_KEY = 'xxxxx'
EMAIL = "xxx@example.org"
APP_NAME = 'XXXX'
LOAD_NOTIFY_LIMIT = 3.0
LOAD_PANIC_LIMIT = 15.0

import os #could be inside the fn to save memory, but that's no good if the server is already overloaded
def panic():
    os.system('killall -9 php-cgi')
    os.system('/etc/init.d/apache2 restart')

def get_load():
    with open('/proc/loadavg', 'r') as f:
        return float(f.read().split(' ')[0])

p = prowlpy.Prowl(API_KEY)

load = 0.0
subject = None
message = None
priority = -2

while True:
    try:
        load = get_load()
        if load > LOAD_NOTIFY_LIMIT:
            if load > LOAD_PANIC_LIMIT:
                (subject, message, priority) = (
                     'Server Overload Panic!',
                     "load average is %f. Running panic function" % load,
                     2
                )
                panic()
            else:
                subject, message, priority = 'Server Overloaded', "load average is %f" % load, 1
        else:
            subject, message, priority = None, None, -2
    except IOError, e:
        subject, message, priority = "Can't read server load", str(e), 2
    if subject:
        try:
            p.add(APP_NAME, subject, message, priority)
        except IOError:
            import smtplib
            s = smtplib.SMTP()
            s.sendmail(EMAIL, EMAIL, """Subject: %s
            %s""" % (subject, message))
    sleep(60)