Projects_devops

LSB Steganography (Least Significant Bit Steganography) LSB (Least Significant Bit) Steganography is a technique used to hide secret data inside an image by modifying the least significant bits of pixel values. Since these bits cause very little visible change in the image, it is an effective and simple way to hide information.

Updated Folder Structure Your project will now include:

php Copy Edit flask-steganography-app/ │── app.py # Main Flask application │── uploads/ # Folder to store uploaded files │── templates/ # HTML template files │ ├── index.html # Main UI for file upload │── static/ # Static files (CSS, JS, images if needed) │── steg.py # Steganography functions (hiding/extracting text) │── requirements.txt # Dependencies (Flask, Pillow, Stegano)

Step 1: Install Required Libraries Run the following command:

pip install flask pillow stegano Flask → For the web app Pillow → Image processing Stegano → Hiding and extracting text in images

to run the python application python app.py

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update the apt repo on your machine

sudo apt update

Installation of python3 and pip

sudo apt install python3 sudo apt install python3-pip

check the packages installed properly or not

python3 --version pip --version

installation of flask

cd ~
mkdir myproject
cd myproject
sudo  apt install python3.12-venv
. .venv/bin/activate
pip install Flask
cd ~

installation of stegano and libgl1

pip install stegano
sudo apt install libgl1

clone the repository

 cd ~
 git clone https://github.com/Rathnakeerthi/Projects_devops.git

install g unicorn

pip install gunicorn
gunicorn -b 0.0.0.0:8000 app:app

Run Gunicorn WSGI server to serve the Flask Application When you “run” flask, you are actually running Werkzeug’s development WSGI server, which forward requests from a web server. Since Werkzeug is only for development, we have to use Gunicorn, which is a production-ready WSGI server, to serve our application.

Install Gunicorn using the below command:

pip install gunicorn

Run Gunicorn:

gunicorn -b 0.0.0.0:8000 app:app 

Gunicorn is running (Ctrl + C to exit gunicorn)!

Use systemd to manage Gunicorn Systemd is a boot manager for Linux. We are using it to restart gunicorn if the EC2 restarts or reboots for some reason. We create a .service file in the /etc/systemd/system folder, and specify what would happen to gunicorn when the system reboots. We will be adding 3 parts to systemd Unit file — Unit, Service, Install

Unit — This section is for description about the project and some dependencies Service — To specify user/group we want to run this service after. Also some information about the executables and the commands. Install — tells systemd at which moment during boot process this service should start. With that said, create an unit file in the /etc/systemd/system directory

sudo vi /etc/systemd/system/steg.service

Then add this into the file.

[Unit]
Description=Flask Steganography App with Gunicorn
After=network.target

[Service]
User=ubuntu
Group=ubuntu
WorkingDirectory=/home/ubuntu/Project_Devops/Python_projects/flask-steganography-app
ExecStart=/home/ubuntu/Project_Devops/Python_projects/flask-steganography-app/venv/bin/gunicorn -b 0.0.0.0:8000 app:app

[Install]
WantedBy=multi-user.target

Then enable the service:

sudo systemctl daemon-reload
sudo systemctl start steg
sudo systemctl enable steg

Check if the app is running with

curl localhost:8000

Run Nginx Webserver to accept and route request to Gunicorn Finally, we set up Nginx as a reverse-proxy to accept the requests from the user and route it to gunicorn.

Install Nginx

sudo apt-get nginx

Start the Nginx service and go to the Public IP address of your EC2 on the browser to see the default nginx landing page

sudo systemctl start nginx
sudo systemctl enable nginx

Edit the default file in the sites-available folder.

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

Add the following code at the top of the file (below the default comments)

upstream flasksteg {
    server 127.0.0.1:8000;
}

Add a proxy_pass to flasksteg at location /

location / {
    proxy_pass http://flasksetg;
}

Restart Nginx

sudo systemctl restart nginx

Tada! Our application is up!

Run the app

 cd Projects_devops/Python_projects/flask-steganography-app/
 python app.py