Multi-stage builds for smaller images in MLOps - Mini Project: Build & Apply

Multi-stage builds for smaller images

📖 Scenario: You are working on a machine learning project that requires a Docker image to run your model training script. You want to keep the final Docker image small to save storage and speed up deployment.Multi-stage builds in Docker help you do this by letting you use one image to build your code and another smaller image to run it.

🎯 Goal: Build a Dockerfile using multi-stage builds that first installs all dependencies and copies your training script, then creates a smaller final image that only contains the necessary runtime files.

📋 What You'll Learn

Create a first build stage named builder using the python:3.12-slim image

In the builder stage, copy train.py and install scikit-learn

Create a second stage named runtime using the python:3.12-alpine image

Copy only the train.py file from the builder stage to the runtime stage

Set the default command to run python train.py in the runtime stage

💡 Why This Matters

🌍 Real World

Multi-stage builds are used in real projects to reduce Docker image size, which saves bandwidth and speeds up deployment.

💼 Career

Understanding multi-stage builds is important for DevOps and MLOps roles to optimize containerized machine learning workflows.

1

Create the builder stage

Write a Dockerfile line to start a build stage named builder using the image python:3.12-slim.

MLOps

# Your code here

Need a hint?

Use the FROM instruction with AS builder to name the stage.

2

Copy train.py and install dependencies in builder

In the builder stage, add lines to copy train.py into the image and install the scikit-learn package using pip.

MLOps

FROM python:3.12-slim AS builder
# Your code here

Need a hint?

Use COPY train.py /app/train.py and RUN pip install scikit-learn.

3

Create the runtime stage and copy train.py

Start a new stage named runtime using python:3.12-alpine. Then copy train.py from the builder stage to /app/train.py in this stage.

MLOps

FROM python:3.12-slim AS builder
COPY train.py /app/train.py
RUN pip install scikit-learn
# Your code here

Need a hint?

Use FROM python:3.12-alpine AS runtime and COPY --from=builder /app/train.py /app/train.py.

4

Set the default command to run train.py

In the runtime stage, add a line to set the default command to python /app/train.py using the CMD instruction.

MLOps

FROM python:3.12-slim AS builder
COPY train.py /app/train.py
RUN pip install scikit-learn

FROM python:3.12-alpine AS runtime
COPY --from=builder /app/train.py /app/train.py
# Your code here

Need a hint?

Use CMD ["python", "/app/train.py"] to set the default command.