Consistent environments across teams in Docker - Mini Project: Build & Apply

Consistent environments across teams

📖 Scenario: Your team needs to ensure everyone uses the same software environment to avoid "it works on my machine" problems. Docker helps by packaging the app and its environment together.In this project, you will create a simple Docker setup for a Python app that prints a greeting. This will help your team run the app consistently on any computer.

🎯 Goal: Build a Dockerfile that sets up a Python environment, copies a Python script, and runs it inside a container. This ensures all team members run the same code with the same Python version and dependencies.

📋 What You'll Learn

Create a Python script named app.py that prints 'Hello from Docker!'

Write a Dockerfile that uses the official Python 3.12 image

Copy app.py into the Docker image

Set the container to run app.py when started

Build and run the Docker container to see the output

💡 Why This Matters

🌍 Real World

Teams use Docker to package apps with their environment so everyone runs the same setup, avoiding bugs caused by different software versions.

💼 Career

Knowing how to create Dockerfiles and run containers is a key skill for DevOps engineers and developers working in teams.

1

Create the Python script

Create a file named app.py with one line of code that prints exactly 'Hello from Docker!'.

Docker

# Create app.py with a print statement
# Your code here

Need a hint?

Use the print() function with the exact text inside single quotes.

2

Start the Dockerfile with Python base image

Create a file named Dockerfile and write the line FROM python:3.12 as the first line to use the official Python 3.12 image.

Docker

# Write FROM python:3.12 as the first line in Dockerfile
# Your code here

Need a hint?

The FROM instruction sets the base image for your Docker container.

3

Copy app.py and set the command

In the Dockerfile, add these two lines after FROM python:3.12: COPY app.py /app.py and CMD ["python", "/app.py"] to copy the script and run it.

Docker

FROM python:3.12
# Add COPY app.py /app.py
# Add CMD ["python", "/app.py"]
# Your code here

Need a hint?

COPY moves your script into the image. CMD tells Docker what to run when the container starts.

4

Build and run the Docker container

Run these two commands in your terminal: docker build -t my-python-app . to build the image, then docker run my-python-app to run the container and see the output.

Docker

FROM python:3.12
COPY app.py /app.py
CMD ["python", "/app.py"]
# Run docker build and docker run commands in terminal
# Your code here

Need a hint?

Use docker build -t my-python-app . then docker run my-python-app. The output should be Hello from Docker!