FROM instruction for base image in Docker - Mini Project: Build & Apply

Using the FROM Instruction to Set a Base Image in Docker

📖 Scenario: You want to create a simple Docker container that runs a Python application. To do this, you need to start with a base image that already has Python installed.

🎯 Goal: Build a Dockerfile that uses the FROM instruction to specify the official Python 3.12 base image.

📋 What You'll Learn

Create a Dockerfile

Use the FROM instruction with the exact base image python:3.12-slim

💡 Why This Matters

🌍 Real World

Dockerfiles are used to create container images that package applications with their environment. Starting with a base image is the first step in building a container.

💼 Career

Understanding the <code>FROM</code> instruction is essential for DevOps engineers and developers working with containers and continuous deployment pipelines.

1

Create a Dockerfile with the FROM instruction

Create a file named Dockerfile and write the FROM instruction with the exact base image python:3.12-slim.

Docker

# Your code here

Need a hint?

The FROM instruction must be the first line in your Dockerfile.

2

Add a label to describe the image

Add a LABEL instruction below the FROM line with the exact key description and value "Python 3.12 slim base image".

Docker

FROM python:3.12-slim
# Your code here

Need a hint?

Use the syntax LABEL key="value" to add metadata.

3

Set the working directory

Add a WORKDIR instruction below the LABEL line to set the working directory to /app.

Docker

FROM python:3.12-slim
LABEL description="Python 3.12 slim base image"
# Your code here

Need a hint?

The WORKDIR instruction sets the directory where commands will run inside the container.

4

Display the Dockerfile content

Write a command to display the contents of the Dockerfile to verify your instructions.

Docker

FROM python:3.12-slim
LABEL description="Python 3.12 slim base image"
WORKDIR /app
# Your code here

Need a hint?

Use RUN cat Dockerfile to print the Dockerfile content during build.