Monit

https://www.the-hawkes.de/monitor-your-raspberrypi-with-monit.html https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-monit

sudo apt-get install monit

sudo nano /etc/monit/monitrc

change to\

set httpd port 2812
use address 192.168.x.x  # only accept connection from localhost
    allow 0.0.0.0/0.0.0.0    # allow localhost to connect to the server and
    allow admin:monit        # require user 'admin' with password 'monit'

monit
monit status
monit reload

Measure temperature of RaspberryPi

check program sensors with path /opt/vc/bin/vcgencmd measure_temp
    if status != 0 then alert