Title: Simple network dashboard with vnstat

	Title: Simple network dashboard with vnstat
	Author: Solène
	Date: 25 November 2021
	Tags: openbsd networking nocloud
	Description: A simple how-to for making an html dashboard with network
	pictures about bandwidth usage

	# Introduction

	Hi! If you run a server or a router, you may want to have a nice view
	of the bandwidth usage and statistics. This is easy and quick to
	achieve using vnstat software. It will gather data regularly from
	network interfaces and store it in rrd files, it's very efficient and
	easy to use, and its companion program vnstati can generate pictures,
	perfect for easy visualization.

	My simple router network dashboard with vnstat
	vnstat project homepage

	Take a look at Abhinav's Notes for a similar setup with NixOS

	# Setup (on OpenBSD)

	Simply install vnstat and vnstati packages with pkg_add. All the
	network interfaces will be added to vnstatd databases to be monitored.

	```shell commands
	# pkg_add vnstat vnstati
	# rcctl enable vnstatd
	# rcctl start vnstatd
	# install -d -o _vnstat /var/www/htdocs/dashboard
	```

	Create a script in /var/www/htdocs/dashboard and make it executable:

	```shell script
	#!/bin/sh

	cd /var/www/htdocs/dashboard/ \|\| exit 1

	# last 60 entries of 5 minutes stats
	vnstati --fiveminutes 60 -o 5.png

	# vertical summary of last two days
	# refresh only after 60 minutes
	vnstati -c 60 -vs -o vs.png

	# daily stats for 14 last days
	# refresh only after 60 minutes
	vnstati -c 60 --days 14 -o d.png

	# monthly stats for last 5 months
	# refresh only after 300 minutes
	vnstati -c 300 --months 5 -o m.png
	```

	and create a simple index.html file to display pictures:

	```html sources
	<html>
	<body>
	<div style="display: inline-block;">
	<img src="vs.png" /><br />
	<img src="d.png" /><br />
	<img src="m.png" /><br />
	</div>
	<img src="5.png" /><br />
	</body>
	</html>
	```

	Add a cron as root to run the script every 10 minutes using _vnstat
	user:

	```crontab code
	# add /usr/local/bin to $PATH to avoid issues finding vnstat
	PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin

	/10 * * * -ns su -m _vnstat -c "/var/www/htdocs/dashboard/vnstat.sh"
	```

	My personal crontab runs only from 8h to 23h because I will never look
	at my dashboard while I'm sleeping so I don't need to keep it updated,
	just replace * by 8-23 for the hour field.

	# Http server

	Obviously you need to serve /var/www/htdocs/dashboard/ from your http
	server, I won't cover this step in the article.

	# Conclusion

	Vnstat is fast, light and easy to use, but yet it produces nice
	results.

	As an extra, you can run the vnstat commands (without the i) and use
	the raw text output to build an pure text dashboard if you don't want
	to use pictures (or http).