Flask App in Docker: 
Docker installation: 
Open terminal 

• sudo apt update  
• sudo apt install docker.io 
• sudo chmod 666 /var/run/docker.sock 
• sudo systemctl start docker 

1. Creating a flask App: 

Create a newfolder:  

flask-docker-app 

Create a python file app.py: 

from flask import Flask 
app = Flask(__name__)
@app.route('/') 
def hello_world(): 
    return 'Hello, Docker!' 
if __name__ == '__main__': 
    app.run(host='0.0.0.0', port=5000) 


2. Create a requirements.txt file to list your dependencies: 
Flask==3.0.3    

3. Create a docker file with name Dockerfile 

FROM python:3.9-slim 
WORKDIR /app 
COPY . /app 
RUN pip install --no-cache-dir -r requirements.txt 
EXPOSE 5000
CMD ["python3", "app.py"] 

4. Building Docker image: 
docker build -t flask-docker-app . 
docker run -p 5000:5000 flask-docker-app 

5. Open browser an run: http://localhost:5000 