Simple Web Application

A minimal Python Flask web application used as the demo app in the KodeKloud Docker for Beginners course.

The app exposes two routes:

Route	Response
/	Welcome!
/how-are-you	I am good, how about you?

Run manually (without Docker)

These steps assume a fresh machine.

1. Select an OS - Ubuntu

2. Update the package index:

   sudo apt-get update

3. Install Flask (this also pulls in Python 3):

   sudo apt-get install -y python3-flask

4. Set the Flask app environment variable:

   export FLASK_APP=app.py

5. Start the application:

   flask run --host=0.0.0.0

Then open http://localhost:5000 and http://localhost:5000/how-are-you in a browser.

Run with Docker

git clone https://github.com/mmumshad/simple-webapp-flask.git
cd simple-webapp-flask
docker build -t simple-webapp-flask .
docker run -p 5000:5000 simple-webapp-flask

Then open http://localhost:5000 and http://localhost:5000/how-are-you in a browser.

The Dockerfile

FROM ubuntu

RUN apt-get update
RUN apt-get install -y python3-flask

COPY app.py /opt/app.py

ENV FLASK_APP=/opt/app.py

ENTRYPOINT ["flask", "run", "--host=0.0.0.0"]

Each instruction mirrors one of the manual steps above — making it easy to see how a Dockerfile is just an automated install script.