Question

I have tried writing a shell script which alerts admin when the disk usage reaches up to 70%. I want write this script in python

#!/bin/bash
ADMIN="[e-mail]"
INFORM=70

df -H  | grep -vE ‘^Filesystem|tmpfs|cdrom’ | awk ‘{ print $5 ” ” $6 }’ | while read   output;
do
use=$(echo $output | awk ‘{ print $1}’ | cut -d’%’ -f1  )
partition=$(echo $output | awk ‘{ print $2 }’ )
if [ $use -ge $INFORM ]; then
echo “Running out of space \”$partition ($use%)\” on $(hostname) as on $(date)” |
mail -s “DISK SPACE ALERT: $(hostname)” $ADMIN
fi
done

Answer 1

The easiest(understandable) approach for you would be to run the df command on an external process and extract the details from the returned output.

To execute a shell command in Python, you need to use subprocess module. You can use smtplib module to send emails to the admin.

I cooked up a small script that should do the job of filtering the filesystems you don’t need to monitor, does some string manipulation to pull out the filesystem and % used values and prints out when the usage exceeds the threshold.

#!/bin/python
import subprocess
import datetime

IGNORE_FILESYSTEMS = ('Filesystem', 'tmpfs', 'cdrom', 'none')
LIMIT = 70

def main():
  df = subprocess.Popen(['df', '-H'], stdout=subprocess.PIPE)
  output = df.stdout.readlines()
  for line in output:
    parts = line.split()
    filesystem = parts[0]
    if filesystem not in IGNORE_FILESYSTEMS:
      usage = int(parts[4][:-1])  # Strips out the % from 'Use%'
      if usage > LIMIT:
        # Use smtplib sendmail to send an email to the admin.
        print 'Running out of space %s (%s%%) on %s"' % (
            filesystem, usage, datetime.datetime.now())


if __name__ == '__main__':
  main()

The output of the executed script would be something like this:

Running out of space /dev/mapper/arka-root (72%) on 2013-02-11 02:11:27.682936
Running out of space /dev/sda1 (78%) on 2013-02-11 02:11:27.683074
Running out of space /dev/mapper/arka-usr+local (81%) on 2013-02-11 02:11