Raspberry Pi monitor

Info

With RPi-Monitor you can monitor various aspects of your Raspberry Pi. The package has its own simple webserver. It works well for smaller screens (mobile phone) and history can be visualized with some graphs. If it still isn't to your liking it allows for some serious tinkering.

• https://xavierberger.github.io/RPi-Monitor-docs/index.html
• https://github.com/XavierBerger/RPi-Monitor

Local webservice, access within the local network with:

• http://192.168.1.2:8888/

Install

Install packages:

sudo apt install librrds-perl libhttp-daemon-perl libjson-perl libipc-sharelite-perl 
sudo apt install libfile-which-perl libsnmp-extension-passpersist-perl
sudo apt install aptitude

Download and install monitor:

wget https://github.com/XavierBerger/RPi-Monitor-deb/blob/develop/packages/rpimonitor_latest.deb
sudo dpkg -i rpimonitor_latest.deb

Remove

Monitor package:

sudo apt-get purge rpimonitor
rm -fr /etc/rpimonitor
rm -fr /usr/share/rpimonitor

Configure

Documentation

man rpimonitord
man rpimonitord.conf
rpimonitord -i

Main configuration files

Main configuration-file with possible references to the other templates:

sudo nano /etc/rpimonitor/template/raspbian.conf

Configuration of the daemon:

sudo nano /etc/rpimonitor/daemon.conf

Modify interval

Default is 10 seconds, changed it to 30 seconds.

sudo nano -l +6 /etc/rpimonitor/daemon.conf

daemon.delay=30

sudo systemctl restart rpimonitor

Note: that if you change the delay, you probably want to delete the "rrd" files that contain the graph history. The delay is used during their creation. They wil be automatically recreated but obviously you will loose the history.

sudo rm /var/lib/rpimonitor/stat/*.rrd

sudo systemctl restart rpimonitor

More info:

• https://oss.oetiker.ch/rrdtool/
• https://codeblog.dotsandbrackets.com/quick-intro-to-rrdtool/

Network monitoring

Uncomment all lines that are commented and comment the lines that contain the configuration message.

sudo nano /etc/rpimonitor/template/network.conf

Tweaking

Edit services.conf to check for running apache webservice

sudo nano /etc/rpimonitor/template/services.conf

dynamic.3.name=http
dynamic.3.source=systemctl show -p SubState --value apache2
dynamic.3.regexp=(.*)

web.status.1.content.1.line.1= Label(data.http,"=='running'","Apache","success") + Label(data.http,"!='running'","apache","danger")

Edit cpu.conf to include CPU throttling

(Rapberry Pi 3)

sudo nano /etc/rpimonitor/template/cpu.conf

dynamic.1.name=cpu_frequency
dynamic.1.source=vcgencmd measure_clock arm | sed -e "s/frequency(45)=//g"
dynamic.1.regexp=(.*)
dynamic.1.postprocess=$1/1000000
dynamic.1.rrd=

Link from the main page directly to the corresponding graph

• Included in new version v2.13+

Modify the function Start() in "rpimonitor.statistics.js" to read a parameter 'graph':

sudo nano -l +26 /usr/share/rpimonitor/web/js/rpimonitor.statistics.js

// ...

function Start() {
  static = getData('static')
  graphconf = getData('statistics')

  //modified: read activestat from url graph parameter
  activestat = GetURLParameter('graph');
  if (activestat == null){
    activestat = localStorage.getItem('activestat') || 0;
  }

  // ... unchanged ...

  activePage = GetURLParameter('activePage');

  // ...
}

// ...

Then modify "uptime.conf" (graph=0) to include a link to the graph. Same for for "cpu.conf" (graph=1), "temperature.conf" (graph=2), etc:

sudo nano /etc/rpimonitor/template/uptime.conf

web.status.1.content.1.name=<a target=_blank href=statistics.html?graph=0>Uptime</a>

Link to logfiles

cd /usr/share/rpimonitor/web
sudo ln -f -s /var/log/wjv/main.log main.log.txt
sudo ln -f -s /var/log/wjv/main.log.1 main.log.1.txt

Graph dips and spikes

There seems to be a problem where recorded values show dips and spikes while the actual value doesn't change. For example, receiving 2.478 continuously, the recorded value would fall to 2.446, then jump to 2.510 and then goes back to 2.478. This may happen about every 10 minutes. Note that at this time the recording delay was set at 60 seconds.

Setting the delay to be around 60 seconds probably causes RRD intervals (of 60 seconds) without a recorded value and therefore anomalies in the recorded values. It looks like this will happen a lot less with a lower value for the delay.

Using LAST instead of AVERAGE

I modified the consolidation function to "LAST" instead of "AVERAGE" for the small intervals so it would record exact values.

Modify the source code (Perl):

sudo nano -l +309 /usr/bin/rpimonitord

	...
	RRDs::create( "$filename",
		"--start", $start,
		"--step", $this->{'daemon'}->{'delay'},
		"DS:$name:$type:600:$min:$max",
		"RRA:LAST:0.5:1:8640",    # 1 day with interval of 10sec
		"RRA:LAST:0.5:6:2880",    # 2 day with interval of 1min
		"RRA:AVERAGE:0.5:60:2016",   # 2 week with interval of 10min
		"RRA:AVERAGE:0.5:180:1488",  # 1 month with interval of 30min
		"RRA:AVERAGE:0.5:360:8784"   # 1 year with interval of 1hour
		);
	...

The files need to be deleted and will be re-created on rspat of the service. RRD file info:

#backup-remove
sudo mv /var/lib/rpimonitor/stat/soc_temp.rrd /var/lib/rpimonitor/stat/soc_temp.rrd.bak
#restart
sudo systemctl restart rpimonitor
#check
rrdtool info /var/lib/rpimonitor/stat/soc_temp.rrd

Debugging

The StartServer-code is around line 1335:

sudo nano -l +1335 /usr/bin/rpimonitord

Start RPi-Monitor in a terminal with logging:

sudo systemctl stop rpimonitor
sudo rpimonitord -vvvvvv

Make it work with a webserver

The Web-server seems to stop regularly. In the Perl code (rpimonitord) there is a "Check if the server is up" part in "Monitor->Run". This is called once every "daemon.delay". With a higher daemon.delay the problem is quite annoying. I changed the code to break-up the delay in 10s parts and check the server every 10s. The problem will still be there but now I only need to wait 10 sec.

Disable the built-in webserver:

sudo nano /etc/rpimonitor/daemon.conf

	daemon.noserver=1

Problem: the rdd files can't be found by apache. We add a symbolic link to point to the right place:

cd /usr/share/rpimonitor/web
sudo ln -s /var/lib/rpimonitor/stat stat

Restart:

sudo service rpimonitor restart

Go to:

• http://<yourserver>/rpimonitor/status.html

Configure Apache2 webserver, port 80 virtual directory

sudo nano /etc/apache2/sites-available/raspberrypi.conf

	<VirtualHost _default_:80>
	 Alias /rpimonitor/ /usr/share/rpimonitor/web/
	 <Directory /usr/share/rpimonitor/web/>
	  AllowOverride None
	  Require all granted
	 </Directory>
	</VirtualHost>

Restart:

sudo systemctl restart apache2

Configure Nginx webserver, port 80 virtual directory

Some tips (for use of nginx webserver):

• https://xavierberger.github.io/RPi-Monitor-docs/35_external.html
• Nginx webserver configuration

sudo nano /etc/nginx/sites-available/raspberrypi4

  server
  {
    listen      80;
    server_name wjv.duckdns.org;
    autoindex off;
    index index.htm;

    location /rpimonitor {
        alias /usr/share/rpimonitor/web;
        allow all;
    }
  }

Restart:

sudo systemctl restart nginx

Snippets

Apply pending upgrades

The monitor notifies you of pending upgrades. To apply the upgrades:

pihole -up
sudo apt upgrade

Upgradable packages are refreshed once a day. To force a refresh manually:

sudo /etc/init.d/rpimonitor update
sudo systemctl restart rpimonitor