Fast process monitor daemon in python with logger and email notifier

process_mon.py

#!/usr/bin/env python                                                                                                                                                                                                                                                         
                                                                                                                                                                                                                                                                               
import os, smtplib                                                                                                                                                                                                                                                             
from sys import exit                                                                                                                                                                                                                                                           
from time import sleep, gmtime, strftime                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                               
########## Configuration here ##############                                                                                                                                                                                                                                   
processname = 'init'                                                                                                                                                                                                                                                            
checkseconds = 5                                                                                                                                                                                                                                                               
maxalerts = 2                                                                                                                                                                                                                                                                  
sender = '[email protected]'                                                                                                                                                                                                                                                   
receivers = ['[email protected]']                                                                                                                                                                                                                                         
emailpassword = 'myemailpass'                                                                                                                                                                                                                                                     
smtpserver = 'smtp.server.net'                                                                                                                                                                                                                                                      
logfilename = 'monitor.log'                                                                                                                                                                                                                                                    
########## End configuration ###########                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                               
message = ("From: Monitor <%s>\r\nTo: Warning <%s>\r\nSubject: e-mail Alert Monitor\r\nProcess is down!" % (sender, ", ".join(receivers)))                                                                                                                                     
fail = 0                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                               
#Crazy logger                                                                                                                                                                                                                                                                  
                                                                                                                                                                                                                                                                               
def writelog (message):                                                                                                                                                                                                                                                        
                                                                                                                                                                                                                                                                               
  global logfile                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                               
  try:                                                                                                                                                                                                                                                                         
    # This tries to open an existing file but creates a new file if necessary.                                                                                                                                                                                                 
    logfile = open(logfilename, "a")                                                                                                                                                                                                                                           
    try:                                                                                                                                                                                                                                                                       
        logfile.write(message)                                                                                                                                                                                                                                                 
    finally:                                                                                                                                                                                                                                                                   
        logfile.close()                                                                                                                                                                                                                                                        
  except IOError:                                                                                                                                                                                                                                                              
    pass                                                                                                                                                                                                                                                                       
 


# Notifying via Email 
def advice():

        try:
                smtpObj = smtplib.SMTP(smtpserver, 25)
                smtpObj.login (sender,emailpassword)
                smtpObj.sendmail(sender, receivers, message)         
                writelog ("%s Successfully sent email\n" % (strftime("%d %b %Y %H:%M:%S", gmtime())))
                smtpObj.quit()
        except SMTPException:
                writelog ("%s Error: unable to send email\n" % (strftime("%d %b %Y %H:%M:%S", gmtime())))
#       print ("exiting...")
#       exit (1)

# Vicente trick of the hell
def monitor():
        global fail
        tmp = os.popen("ps -Af").read()
        proccount = tmp.count(processname)
        if proccount < 1:
                fail = fail + 1
                writelog ('%s %s **STOPPED** (alert %d)\n' % (strftime("%d %b %Y %H:%M:%S", gmtime()), processname, fail))
                if fail == maxalerts:
                        advice()
        else:
                fail = 0
        sleep(checkseconds)


def main():

  while 1:
        monitor()
 
# Dual fork hack to make process run as a daemon thanks to Active Programmer Network
if __name__ == "__main__":
  try:
    pid = os.fork()
    if pid > 0:
      exit(0)
  except OSError, e:
    exit(1)
 
  os.chdir("/tmp")
  os.setsid()
  os.umask(0)
 
  try:
    pid = os.fork()
    if pid > 0:
      exit(0)
  except OSError, e:
    exit(1)
 
  main()