Graph data with Grafana

This section is optional. Using Grafana, you can read the Redis database and graph it. Only the emulated deployment with QEMU will be detailed here, but grafana can be used with a real board too.

Prerequisites

Redis configuration

The grafana service will be running on the host. In order to make it work, it is compulsory to modify Redis configuration’s file on target. There are two ways to do this:

Start the service with another config file given with the package industrial-demo-config
Modify Redis configuration file in /etc/redis.conf everytime you start a new session on target

First method

First, stop Redis service:

systemctl stop redis

Then, start Redis with the new configuration file:

redis-server /etc/gateway/redis.conf

Second method

sudo vim /etc/redis.conf

There are two lines to change:

l-69: change bind 127.0.0.1 to bind 0.0.0.0
l-88: change protected-mode yes to protected-mode no

Then, restart the Redis service:

systemctl restart redis

QEMU configuration

Since Grafana will be installed on the host, we have to forward Redis’ port when QEMU is started. If you use Redis default port (6379), use this new command to start QEMU:

# For Ubuntu
OVMF="/usr/share/qemu/OVMF.fd"
# Uncomment/change for Fedora
#OVMF="/usr/share/OVMF/OVMF_CODE.fd"
PORT_SSH=3333

qemu-system-x86_64 \
    -hda "Redpesk-OS.img" \
    -enable-kvm -m 2048 \
    -cpu kvm64 \
    -cpu qemu64,+ssse3,+sse4.1,+sse4.2,+popcnt \
    -smp 4 \
    -vga virtio \
    -device virtio-rng-pci \
    -serial mon:stdio \
    -serial null \
    -soundhw hda \
    -net nic \
    -net user,hostfwd=tcp::$PORT_SSH-:22,hostfwd=tcp::6379-:6379 \
    -bios $OVMF

Note that, by default redpesk has a firewall enabled that would block incoming connections to TCP/6379. You could either enable incoming connections in redpesk’s firewall or use an SSH connection to the virtual machine to forward the Redis’ port.

In order to change redpesk firewall’s configuration, use the following for a temporary configuration:
sudo firewall-cmd --zone=public --add-port=6379/tcp

Or, for a permanent configuration:

sudo firewall-cmd --add-port 6379/tcp --permanent
sudo firewall-cmd --reload

In order to open an SSH tunnel to the Redis’ port:
ssh -L 6379:localhost:6379 root@localhost -p $PORT_SSH

Grafana installation

In this demo, we will install Grafana natively. You can find further information here.

Installing on Debian

On a native Debian or Ubuntu system:

sudo apt-get install -y apt-transport-https
sudo apt-get install -y software-properties-common wget
wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -

Then, add this repository for stable releases:

echo "deb https://packages.grafana.com/oss/deb stable main" | sudo tee -a /etc/apt/sources.list.d/grafana.list

After you add the repository:

sudo apt-get update
sudo apt-get install grafana

Start the service:

sudo systemctl restart daemon-reload
sudo systemctl start grafana-server

Installing on Fedora

sudo dnf install grafana
sudo systemctl start grafana-server

Installing on OpenSUSE

sudo zypper install grafana
sudo systemctl start grafana-server

Grafana configuration

You can access to gafana UI on localhost:3000, default username and password are admin.

Install the Redis plugin

Go to Configuration > Plugins, and install the plugin named redis.

Add a data source

In Configuration > Data sources, click on add data source and select redis. You should get a configuration like this (you just have to put 127.0.0.1:6379 for the address):

Database configuration

Add a dashboard

Now that the database is added, let’s create a dashboard. You can either create one or use a configuration created for the demonstration.

The dashboard should use the Redis datasource and use a query to redis through TS.GET on the key wind_direction_deg. Make sure the data is refresh every second by setting a streaming interval of 1000 ms.

The configuration file is available with this command:

wget https://github.com/redpesk-samples/anemometer-industrial-demo/-/raw/master/configs/grafana_config.json

In the grafana UI, go to Dashboards > Import, and upload this file.

Results

There we go, the demo is deployed and the data are on a grafana dashboard.

Grafana dashboard

Discover the demo