vnStat Alert

What is it?

This is a simple python script to control data usage by shutting down the machine when a set limit is reached and sends an email alert to the admin.

Requirements

• vnStat

vnStat Configuration

1. Edit /etc/vnstat.conf

• Change MonthRotate on line 10 to start date of billing period (1-28)

2. Setup vnStat monitoring

• sudo vnstat -u -i eth0
  • Replace eth0 with network interface to be monitored, the command vnstat --iflist will show all available network interfaces

3. Start the vnStat daemon and set to run on boot

• sudo vnstatd -d
• Add vnstat -d above exit 0 line in /etc/rc.local

Script Configuration

1. Change the number on Line 7 to the usage limit in GB (whole numbers only)
2. Add script to crontab to run automatically

• Add 5 * * * * /path/to/script.py to root crontab (sudo crontab -e)
  • Replace the 5 with how often you want the script to check usage in minutes
  • Replace /path/to/script.py with the actual path to the script (obviously)

Comments

• Update and addition of conversion code is because vnStat uses GiB (gibibyte) rather than GB (gigabyte) and 1 GiB is more than 1 GB

Changelog

Version 2.0

• Completely changed how script retrieves usage data

Version 2.1

• Added conversion from GB to GiB within the script for more accuracy
• Added units checking for MiB and GiB

Version 3.0

• Cleanup and new README
• Email capable version of script added

Licence

This software is licensed under the MIT License, you can view the license terms at https://jibreil.mit-license.org/ or, in the LICENSE.md file.