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.

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

    
        

                

                

                

        
        

    

```

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).