Monitor Fritz!Box connection statistics with Grafana, InfluxDB and Raspberry Pi

I’ve recently stumbled over an article in the german magazine C’T about visualisations of your Fritz!Box’s connection. The solution looked quite boring and outdated, since it used MRTG for the graph creation.

I’ve started searching for a better solution using Grafana, InfluxDB and my Raspberry Pi and found this great blog post. I’ve already explained how to install Grafana and InfluxDB in this post, so I’ll concentrate on the Fritz!Box related parts:

Start with the installation of fritzcollectd. It is a plugin for collectd.

sudo apt-get install -y python-pip
sudo apt-get install -y libxml2-dev libxslt1-dev
sudo pip install fritzcollectd

Now create a user account in the Fritz!Box for collectd. Go to System, Fritz!Box-user and create a new user with password, who has access from internet disabled. The important part is to enable „Fritz!Box settings“.

Additionally make sure that your Fritz!Box is configured to support connection queries using UPnP. You can configure this under „Home Network > Network > Networksettings“. Select „Allow access for applications“ as well as „Statusinformation using UPnP“.

Next part is the installation and configuration of collectd:

sudo apt-get install -y collectd
sudo nano /etc/collectd/collectd.conf

Enable the python and network plugins by removing the hashtag

LoadPlugin python
[...]
LoadPlugin network

Scroll down till you’ll see the plugin configuration and configure the port and IP for collectd

<Plugin network>
    Server "127.0.0.1" "25826"
</Plugin>

Enable the python plugin and configure the module with the username and password of the user you’ve created. Make also sure to use the right address.

<Plugin python>
    Import "fritzcollectd"

    <Module fritzcollectd>
        Address "fritz.box"
        Port 49000
        User "user"
        Password "password"
        Hostname "FritzBox"
        Instance "1"
        Verbose "False"
    </Module>
</Plugin>

Since you’ve already got a running InfluxDB, you’ll just need to enable collectd as data source:

sudo nano /etc/influxdb/influxdb.conf

Search for the [collectd] part and replace it with

[[collectd]]
  enabled = true
  bind-address = "127.0.0.1:25826"
  database = "collectd"
  typesdb = "/usr/share/collectd/types.db"

Reboot collectd and influx to activate the changes made

sudo systemctl restart collectd
sudo systemctl restart influxdb

Login to your grafana installation and configure a new datasource. Make sure to set the collectd database. If you’re using credentials for the InfluxDB, you can add them now. If you’re not using authentication you can disable the „With credentials“ checkbox.

Check if your configuration is working by clicking on „Save & Test“.

If everything worked, you can proceed to importing the Fritz!Box Dashboard from the Grafana.com dashboard. The ID is 713. Make sure to select the right InfluxDB during the import setup.

After clicking on import, you’ll should be able to see your new Dashboard. It might take a few minutes/hours until you’ve gathered enough data to properly display graphs.

Be aware though that if you start gathering this much data you’ll might end up with „insufficient memory“ errors. You’ll might want to tweak your InfluxDB settings accordingly.

Auto mount NFS shares on Raspbian

I’m using influxdb on my Raspberry Pi in combination with a NFS mount. The NFS mount is on my Synology NAS and should store the database data of influxdb. Reason for this setup is that I fear that the SD card won’t survive the many write/read cycles caused by a database writing to it.

The shared folder on my Synology is configured to be accessible by various IPs in my network:

The problem with Raspbian is that I’ve tried to auto mount the NFS share on startup, so that the influxdb service can directly write to the NFS mount. 

I’ve used these settings in my /etc/fstab to mount the volume automatically:

<DS IP>:/volume1/databases /mnt/databases nfs auto,user,rw,nolock,nosuid 0 0

This doesn’t work properly since my influxdb is often dead after a restart, but if I check the mounted volumes I see the NFS volume mounted properly.

However, there’s a tool called autofs which already helped me with a similar problem on my Mac when I moved my iTunes library to the Synology share.

Install autofs using

sudo apt-get install autofs

Open the file /etc/auto.master and add something like this

/mnt    /etc/auto.databases     -nosuid,noowners

Now create a file called /etc/auto.databases with this content

databases       -fstype=nfs,user,nolock,nosuid,rw <DS IP>:/volume1/databases

Unmount the existing NFS share. Remove/comment out the line for the nfs mount in your /etc/fstab so that it doesn’t conflict with autofs. Restart autofs with

sudo service autofs restart

Now check the content of your mount point with e.g.

ls /mnt/databases

Autofs should now automatically mount the NFS share. This might take a while, which is a good sign that the mount is loaded. You can also verify with

mount

that your NFS share is mounted to e.g. /mnt/databases. If you’ll restart now, influxdb should be happy on restart. When it tries to start, autofs will see the access to the mounted folder and will mount the NFS share before influxdb can start up properly.

Configure influxDB to store its data in a different folder

The default location of the influxDB data is /var/lib/influxdb. If you want to change the location, you’ll need to configure three folders to be in a different place. The changes should be done in the file /etc/influxdb/influxdb.conf

...
[meta]
  # Where the metadata/raft database is stored
  #dir = "/var/lib/influxdb/meta"
  dir = "/mnt/databases/influxdb/meta"
...
[data]
  # The directory where the TSM storage engine stores TSM files.
  #dir = "/var/lib/influxdb/data"
  dir = "/mnt/databases/influxdb/data"

  # The directory where the TSM storage engine stores WAL files.
  #wal-dir = "/var/lib/influxdb/wal"
  wal-dir = "/mnt/databases/influxdb/wal"

I’m using this to store the data on a NFS share which is mounted automatically. If you want to keep your existing data, move the existing content of /var/lib/influxdb to the new location.

Make sure, that the new location is owned by influxdb user and group.

Improve OpenVPN security on Synology DiskStations

I’m using OpenVPN on my Synology DiskStation with certificates instead of Preshared Keys. A few days ago I’ve wanted to login to my VPN and it wasn’t working. After checking the log file I’ve seen that there were some issues with the used configuration file for OpenVPN.

Tue Nov 20 23:04:27 2018 Cipher algorithm 'TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-256-CB' not found
Tue Nov 20 23:04:27 2018 Exiting due to fatal error

How can this be? The configuration worked for months without problems? I’ve started to remember that I’ve started to increase the security of my OpenVPN configuration using a few parameters. The Cipher algorithm is one of them. This page describes some of the changes I’ve made (unfortunately only in German).

I’ve added the tls-cipher and tls-auth options as last parameter lines to my configuration file. The synology web UI tried to parse those parameters as cipher and auth parameter when it shows those values as part of the DSM UI.

I’ve reorderded the tls-auth and tls-cipher parameter to be above the auth and cipher parameters and the DSM UI is now able to show those values correct. This will enable you to restart the OpenVPN service from the WebUI without the need to login via SSH.

How do you get supported values for auth, cipher and tls-cipher you might wonder? Just execute

openvpn --show-tls

to get the supported tls-cipher you might line up with a : separated.

openvpn --show-digests

shows you the allowed values for auth and

openvpn --show-ciphers

will show the allowed values for cipher. However, cipher and auth can also be preselected from the DSM UI.

Don’t forget to use the same values in your OpenVPN configuration on your VPN client as well, otherwise the connection won’t work.

Howto install InfluxDB and Grafana on a Raspberry Pi 3

Inspired by a friend I’ve decided to install InfluxDB and Grafana on my Raspberry Pi 3. InfluxDB is a database optimized for storing time related data like measurements of my recently installed particle sensor. Grafana is used to create beautiful graphs to display the stored data.

The InfluxDB installation can be done in a few simple steps:

This will install the InfluxDB without a user and any rights. You can read up further on that topic. Ideally you should setup an user for authentication but since some IoT devices do not support this I’m not going to explain it here.

The Grafana installation is similar simple:

Please make sure that you’ll get the most current version from github and replace it in the wget command:

First login to Grafana:

Now you’re ready to configure Grafana. Go to http://<ip-of-grafana-machine>:3000 and setup a new username and password for the webinterface. The default is admin/admin

Configure InfluxDB as datasource in Grafana:

You need to configure a datasource under http://<ip-of-grafana-machine>:3000/datasources

Enter as name the name of the database you’ve created earlier. In this case it was topic.

The type of the database is InfluxDB.

The HTTP connection URL is http://localhost:8086

Hit Save & Test, once you’ve configured everything to your liking. The connection to the database should work now.