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Anusha Kuppili
Anusha Kuppili

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Shrink Your Docker Image by 60% Using Multi-Stage Builds and Distroless Containers

#docker #devops #containers #womenintech

Hey Devs! 👋

I’m Anusha, the voice behind Data Enthusiast Era — a channel where I simplify DevOps, Data Science, and MLOps, especially for folks getting started.

Recently, I managed to reduce a Docker image from 146MB to just 57MB.

No tricks. Just Multi-Stage Docker Builds and Distroless Containers.

Here’s how I did it — explained in a way that actually makes sense if you're new to Docker or DevOps.

🐳 The Problem: Docker Images Get Bloated Fast

When we use official base images like python:3.11 or node, they include:

  • a shell
  • compilers
  • package managers
  • other stuff you don’t need at runtime

This makes the image:

  • Bigger
  • Slower to deploy
  • More vulnerable

✨ The Solution: Multi-Stage Builds

With Multi-Stage Builds, we split the Dockerfile into two parts:

  1. One for building (with all tools needed)
  2. One for running (with only the app and its dependencies)

It’s like packing light for production — just what you need to survive!

🔒 Bonus: Use Distroless Images

Distroless images are minimal base images built by Google.

They don’t include:

  • /bin/bash
  • a shell
  • any package manager

Which means:

  • ✨ Smaller
  • 🔐 More secure
  • ⚡ Faster to run

⚙️ My Real Example (Python App)

Step 1: Traditional Dockerfile 

FROM python:3.11-slim
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
CMD ["python", "main.py"]
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🛑 Image size: 146MB

Step 2: Multi-Stage + Distroless

FROM python:3.11-slim AS builder
WORKDIR /app
COPY requirements.txt .
RUN pip install --target=/install -r requirements.txt
COPY . .

FROM gcr.io/distroless/python3
COPY --from=builder /install /usr/local/lib/python3.11/site-packages
COPY --from=builder /app /app
WORKDIR /app
CMD ["main.py"]
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✅ Image size: 57.8MB

📊 Result:
Build Type Image Name Size
Traditional demo-bloat 146MB
Distroless demo-distroless 57.8MB

🎉 That’s a 60% image size reduction — in production, that’s a huge win.

🔍 Why This Matters
⚡ Pull/push images faster

🔐 Reduce attack surface

🧹 Avoid leftover tools and clutter

💸 Save cloud storage and bandwidth

🎥 Watch the Full Demo
Want to see me explain and run this live?
▶️ Watch the full video on YouTube

🙌 Final Thoughts
If you’re starting out with Docker or DevOps, don’t wait to learn about multi-stage builds — it’s a game changer.

I’m Anusha Kuppili — a woman in tech and the creator of Data Enthusiast Era, where I make tech concepts simple, visual, and fun to learn.

Let me know in the comments:
👉 How big is your Docker image right now?
Let’s shrink it together!

💡 Follow me on:
🎥 YouTube: https://www.youtube.com/@DataEnthusiastEra

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