Docker + Django in 10 Days: From Zero to Production [Day: 02]

🎯 Goal of Day 2

By the end of today, you will:

• Clearly understand Images vs Containers (practically)

• Run your first Docker container

• Learn the most important Docker commands

• See how Docker actually works on your machine

Today is hands-on, but still beginner-friendly.

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🔁 Quick Recap from Day 1 (30 seconds)

• Image = blueprint 🧱

• Container = running app 🏃

• Dockerfile = recipe 📜

• Docker = consistent environment everywhere

Keep this in mind as we move.

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🧠 Image vs Container (Real Example)

Let’s say:

• Image: python:3.12

• Container: Python running in your terminal

You can:

• Create 100 containers from 1 image

• Delete containers → image still stays

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🚀 Your First Docker Command

Open your terminal and run:

docker run hello-world

What just happened?

Docker did this automatically:

1. Looked for hello-world image locally

2. Didn’t find it

3. Downloaded it from Docker Hub

4. Created a container

5. Ran it

6. Printed a message

7. Exited

🎉 Congrats — you just ran your first container

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🌍 Docker Hub (Very Important)

Docker Hub is like GitHub for Docker images

Website:
https://hub.docker.com/

Examples:

• python

• postgres

• redis

• nginx

You’ll use these a LOT in Django-DRF.

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🧪 Running a Real Container (Python Example)

Run this:

docker run -it python:3.12

What this means:

• -it → interactive terminal

• python:3.12 → image name + version

You’ll enter a Python shell inside a container 🐍

Try inside it:

print("Hello from Docker")

Exit Python:

exit()

Exit container:

exit

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📦 Important Docker Commands (Must Know)

🔍 See Images

docker images

🔍 See Running Containers

docker ps

🔍 See All Containers (even stopped)

docker ps -a

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▶️ Run a Container

docker run image_name

Example:

docker run python:3.12

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🛑 Stop a Running Container

docker stop <container_id>

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❌ Remove a Container

docker rm <container_id>

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❌ Remove an Image

docker rmi <image_id>

⚠️ You must stop & remove containers first.

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🧠 Very Important Concept: Containers Are Ephemeral

When a container stops, its data is gone (by default).

Example:

• You install something inside container

• Stop it

• Run a new container

• It’s clean again

📌 Solution (later days):

• Volumes

• Bind mounts

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🧩 How This Relates to Django-DRF

In Django terms:

• Image → Django app template

• Container → Running Django server

• Rebuild image → Code/environment changes

Soon, you’ll do:

docker run django_app

Instead of:

python manage.py runserver

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🧠 Mental Model Update

Today you learned this loop:

docker run → container starts
container stops → container is gone
image stays → reusable

This is the heart of Docker.

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📚 Official Docs (Short Reads)

• Docker run command
  https://docs.docker.com/engine/reference/commandline/run/

• Docker Hub
  https://docs.docker.com/docker-hub/

Bookmark them — don’t memorize.

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📝 Homework for Day 2

1. Run:

    docker run hello-world
   

2. Run Python container:

    docker run -it python:3.12
   

3. Check:

    docker images
    docker ps -a
   

4. Stop & remove at least one container manually

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⚠️ Common Beginner Mistakes

• Forgetting to remove stopped containers

• Thinking containers store data permanently

• Panic when container exits 😄 (it’s normal)

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✅ End of Day 2 Summary

• You ran real containers

• You understand images vs containers practically

• You learned essential Docker commands

• You’re ready to build images next

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