Actions

Glances can trigger actions on events for warning and critical thresholds.

By action, we mean all shell command line. For example, if you want to execute the foo.py script if the last 5 minutes load are critical then add the _action line to the Glances configuration file:

[load]
critical=5.0
critical_action=python /path/to/foo.py

All the stats are available in the command line through the use of the Mustache syntax. Chevron is required to render the mustache’s template syntax.

Additionaly to the stats of the current plugin, the following variables are also available: - {{time}}: current time in ISO format - {{critical}}: critical threshold value - {{warning}}: warning threshold value - {{careful}}: careful threshold value

Another example would be to create a log file containing used vs total disk space if a space trigger warning is reached:

[fs]
warning=70
warning_action=python /path/to/fs-warning.py {{mnt_point}} {{used}} {{size}}

Note

For security reasons, Mustache-rendered values are sanitized: the characters &&, |, > and >> are replaced by spaces before execution. This prevents command injection through user-controllable data such as process names, container names or mount points.

As a consequence, shell operators (pipes, redirections, command chaining) cannot be used directly in action command lines. If your action requires pipes, redirections or chained commands, write a shell script and call it from the action instead.

For example, to create a log file containing the total user disk space usage for a device and notify by email each time a space trigger critical is reached, create a shell script /etc/glances/actions.d/fs-critical.sh:

#!/bin/bash
# Usage: fs-critical.sh <time> <device_name> <percent>
echo "$1 $2 $3" > /tmp/fs.alert
python /etc/glances/actions.d/fs-critical.py

Then reference it in the configuration file:

[fs]
critical=90
critical_action_repeat=/etc/glances/actions.d/fs-critical.sh {{time}} {{device_name}} {{percent}}

Within /etc/glances/actions.d/fs-critical.py:

import subprocess
from requests import get

fs_alert = open('/tmp/fs.alert', 'r').readline().strip().split(' ')
device = fs_alert[0]
percent = fs_alert[1]
system = subprocess.check_output(['uname', '-rn']).decode('utf-8').strip()
ip = get('https://api.ipify.org').text

body = 'Used user disk space for ' + device + ' is at ' + percent + '%.\nPlease cleanup the filesystem to clear the alert.\nServer: ' + str(system)+ '.\nIP address: ' + ip
ps = subprocess.Popen(('echo', '-e', body), stdout=subprocess.PIPE)
subprocess.call(['mail', '-s', 'CRITICAL: disk usage above 90%', '-r', 'postmaster@example.com', 'glances@example.com'], stdin=ps.stdout)

Note

You can use all the stats for the current plugin. See https://github.com/nicolargo/glances/wiki/The-Glances-RESTFUL-JSON-API for the stats list.

It is also possible to repeat action until the end of the alert. Keep in mind that the command line is executed every refresh time so use with caution:

[load]
critical=5.0
critical_action_repeat=/home/myhome/bin/bipper.sh