This is a simple script that will emit a warning to stderr when your disk usage surpasses a configured threshold. StdErr output was chosen for its simplicity, and because it's very easy to configure a cron job to send you an email any time an error occurs.
Python pyaml module
sudo pip3 install pyaml
logger program, which should be on most distributions
First, make sure you have python3 and pip3 installed
Use pip3 to make sure you have the python module "pyaml" installed
Create a configuration file somewhere.
Create a Crontab entry that will call this script with an argument "--config" followed by the path to your configuration file.
(examples found below)
This script needs command line arguments to work. Primarily, it needs to know the location of at least one valid configuration file
Specifies a path to a configuration file or directory. If a directory is specified, it will be scanned for configuration files.
Assuming you can invoke Python 3 with the command
python3, here's a quick example using two configuration files:
python3 /path/to/disk-usage-warn --config "/my/config/path-1" --config "/my/config/path-2"
As mentioned, the easiest way to use this script is with Crontabs. By default, cron jobs will send you an email any time a script outputs to stdout or stderr. Since this script will output lots of information onto stdout, and only output to stderr when a disk has become full, it's useful to redirect stdout to /dev/null, like so:
python3 /path/to/disk-usage-warn --config "/path-to-config" > /dev/null
So, in order to run this script every 5 minutes, use something like the following:
*/5 * * * * python3 /path/to/disk-usage-warn --config "/path-to-config" > /dev/null
The examples above assume you can invoke Python 3 with the command