Install Monit on Debian

Monit is an open-source monitoring tool for Linux.

Installation

Monit is available in Debian repositories:

sudo apt update
sudo apt install monit

Enable it to run as a service:

sudo systemctl enable monit.service

Basic Setup

The default configuration file is at /etc/monit/monitrc:

sudo nano /etc/monit/monitrc

Example configuration with some options updated:

set daemon 20           # Update healthcheck interval to 20s
   with start delay 120 # Delay the first check by 2 minutes after Monit start
...
set httpd port 2812 and
    use address 127.0.0.1  # Your IP Address
    allow admin:monit      # Require user 'admin' with password 'monit'

This enables the web interface at http://127.0.0.1:2812.

Note: Change the IP address in the configuration file to match your server.

In this example, Monit monitors NGINX and restarts it when it stops unexpectedly. Enable the bundled NGINX config:

sudo ln -s /etc/monit/conf-available/nginx /etc/monit/conf-enabled/

Reload Monit to apply:

sudo systemctl reload monit.service

Done. Try stopping NGINX and watch Monit restart it automatically.

References

• Using Monit process monitoring on Ubuntu/Debian