hamzaziizzz/Kafka-WebApp

Configuring Raspberry Pi as a Recognition Message Displayer

1. Installing OS

Click the following link to get started with your Raspberry Pi:
https://www.raspberrypi.com/documentation/computers/getting-started.html

Additionally, you can walk through the following link to do your custom configurations:
https://www.raspberrypi.com/documentation/computers/configuration.html

2. Enabling Kafka Consumer's Flask Application Service

The Structure of Flask Application

Kafka-WebApp
   ├── static/
   │   └── img/
   │       ├── abesit_logo.png
   │       └── giventures_logo.png
   ├── templates/
   │   ├── index.html
   ├── app.py
   ├── parameters.py
   └── requirements.txt

The parameters.py file

The parameters.py file contains two important information to fetch messages from the Kafka Server which are the address of the Kafka Broker and the topic name. You need to change these as per your requiremnets.

# Kafka IP and Port
CONFLUENT_KAFKA_IP_ADDRESS = '192.168.12.1'
CONFLUENT_KAFKA_PORT = 9092

# Kafka topic for messages
CONFLUENT_KAFKA_TOPIC = 'feedback_messages_topic_for_library-gate'

Once you made these, the next step is install the requirements required by the Kafka-WebApp

The requirements.txt file

The requirements.txt file contains the packages/libraries required for the Kafka-WebApp

You can install these requirements by running the following command on the Raspberry Pi terminal

python3 -m venv venv
source venv/bin/activate

python3 -m pip install --upgrade pip
python3 -m pip install -r requirements.txt

Once you made these changes you are ready to setup your flask application service.

The Flask Application Service

Step - 1) Create flask-application-startup.sh

This file is responsible for starting the flask application.

First, copy the below contents.

#!/bin/bash

# Change directory to Kafka Web Application
cd /home/raspberry/Kafka-WebApp

# Activate the virtual environment
source venv/bin/activate

# Start the application at a specified port and open it to all incoming networks
python3 -m flask --app app.py run --host 0.0.0.0 --port 9090

Now, create a flask-application-startup.sh file by running the following command and paste the copied contents into it.

sudo nano /usr/local/bin/flask-application-startup.sh

Step - 2) Create flask-application-startup.service

This file is responsible for creating a service for our flask application which will help in automatically start the application on system reboot.

Copy the below contents.

[Unit]
Description=Kafka Web Application

[Service]
ExecStart=/usr/local/bin/flask-application-startup.sh

[Install]
WantedBy=multi-user.target

Now, create a flask-application-startup.service file by running the following command and paste the copied contents into it.

sudo nano /etc/systemd/system/flask-application-startup.service

Step - 3) Start and Enable the Service

Reload the daemon

sudo systemctl daemon-reload

Start the service

sudo systemctl start flask-application-startup.service

Check the Status of the Service

sudo systemctl status flask-application-startup.service

Enable the service to automatically restart on system reboot

sudo systemctl enable flask-application-startup.service

3. The KIOSK Mode

Step - 1) Install the Chromium Browser and Other Packages

sudo apt-get update
sudo apt-get install chromium-browser unclutter xdotool

Step - 2) Create kiosk-startup.sh

This file is responsible for starting the Chromium Browser in KIOSK Mode.

Copy the below contents.

#!/bin/bash

xset s noblank
xset s off
xset -dpms

unclutter -idle 0.5 -root &

sed -i 's/"exited_cleanly":false/"exited_cleanly":true/' /home/raspberry/.config/chromium/Default/Preferences
sed -i 's/"exit_type":"Crashed"/"exit_type":"Normal"/' /home/raspberry/.config/chromium/Default/Preferences

/usr/bin/chromium-browser --noerrdialogs --disable-infobars --kiosk http://localhost:9090 &  # Adjust the URL

while true; do
    xdotool keydown ctrl+Tab; xdotool keyup ctrl+Tab;
    sleep 10
done

Now, create a kiosk-startup.sh file by running the following command and paste the copied contents into it.

sudo nano /usr/local/bin/kiosk-startup.sh

Step - 3) Create kiosk-startup.service

This file is responsible for creating a service for our kiosk startup which will help in automatically start the kiosk on system reboot.

Copy the below contents.

[Unit]
Description=Kiosk Mode Flask Application
Wants=graphical.target
After=graphical.target

[Service]
Environment=DISPLAY=:0.0
Environment=XAUTHORITY=/home/raspberry/.Xauthority
Type=simple
ExecStart=/bin/bash /usr/local/bin/kiosk.sh
Restart=on-abort
User=raspberry
Group=raspberry

[Install]
WantedBy=graphical.target

Now, create a kiosk-startup.service file by running the following command and paste the copied contents into it.

sudo nano /etc/systemd/system/kiosk-startup.service

Step - 4) Start and Enable the Service

Reload the daemon

sudo systemctl daemon-reload

Start the service

sudo systemctl start kiosk-startup.service

Check the Status of the Service

sudo systemctl status kiosk-startup.service

Enable the service to automatically restart on system reboot

sudo systemctl enable kiosk-startup.service

4. Reboot the System

To make these settings effect on the system, we will bw needing to restart the system. You can do this by running the following command in your terminal.

sudo reboot -h now