Simple script to ping a list of IP addresses and alert on slack if they are down.
You will most likely need to run pip3 install slackweb from the command line to get this to work.
Create a slack webhook for the desired channel using these instructions, and paste the webhook into the slack variable:
https://api.slack.com/messaging/webhooks
Look for any variables that need to be changed... paths, webhook urls, etc.
Set your hostnames and IPs in hosts.csv.
set an @reboot crontab entry using crontab -e like so:
@reboot python3 /home/pi/pathtofile/ping-slackalert/ping.py
These instructions are geared toward raspi, but this should work on just about any *nix platform.