Learn Docker

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Day 1 — Foundations: Why Containers Exist

Goal: Understand the problem Docker solves

We will learn:

• What virtualization means in computing

• How traditional servers evolved → Virtual Machines → Containers

• What a VM actually contains (hypervisor, guest OS, resources)

• What a container actually contains (process isolation, shared kernel)

• Difference between VM and container in:

  • startup time
  • resource usage
  • portability
  • scalability

• Real industry problems solved by containers (works on my machine issue)

• Basic terminology:

  • image
  • container
  • host
  • runtime

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Day 2 — Running Containers & Accessing Applications

Goal: Run our first container and access an app

We will learn:

• Networking basics needed for Docker:

  • IP address
  • ports
  • how browser reaches an application

• Docker architecture overview:

  • Docker CLI
  • Docker Engine
  • Docker Registry

• Installing Docker Desktop / Docker Engine

• Running containers using public images

• Basic Docker commands (run, ps, stop, rm, images)

• Understanding images vs containers

• Accessing an application via browser using ports

• Understanding: “application is running inside a container”

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Day 3 — Building Our Own Image (React Application)

Goal: Create our first custom Docker image

We will learn:

• Running React app without Docker (local setup problems)
• Why we build our own images instead of using public ones
• What a Dockerfile is and why it exists
• Build image → run container workflow
• Accessing our own application from browser
• Image tagging (versioning & naming)
• Docker Hub introduction
• Pushing image to Docker Hub

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Day 4 — Backend Containers & Data Persistence

Goal: Containerizing backend and managing runtime data

We will learn:

• Dockerizing a Python (FastAPI) application
• Inspecting running containers
• Viewing container logs
• Executing commands inside containers
• Why container data disappears
• Docker volumes concept
• Docker volume types
• Creating and attaching volumes
• Persisting application data

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Day 5 — Docker Networking Concepts

Goal: Understand how containers communicate

We will learn:

• What networking means in containers
• Bridge network concept
• Running multiple containers
• Container-to-container communication
• Accessing internet from container
• Different kinds of Docker networks
• Basic troubleshooting connectivity

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Day 6 — Networking Practical Deep Dive

Goal: Real hands-on networking behavior

We will do:

• Create custom networks
• Connect containers to same network
• Multi-container communication demo
• Network isolation demo
• Understanding internal vs external access

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Day 7 — Dockerfile Deep Dive

Goal: Understand how images are built internally

We will learn:

• All Dockerfile instructions explained
• Build vs runtime commands
• Entrypoint VS Cmd difference
• Best practices in writing Dockerfile
• Optimization strategies

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Day 8 — Multi-Stage Builds & Image Optimization

Goal: Production-ready images

We will learn:

• Why large images are bad
• Multi-stage builds concept
• Build stage vs runtime stage
• Creating lightweight production images
• Security improvements in containers

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Day 9 — Docker Compose & Real Application

Goal: Run complete application stack

We will learn:

• Docker Compose basics

• Running multiple services together

• Deploying a 3-tier application:

  • frontend
  • backend
  • database

• Container resource limits

• Introduction to orchestration (Docker Swarm concept overview)

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Course Outcome

By the end, students will be able to:

• Understand containers internally
• Build production-ready images
• Run multi-service applications
• Debug container issues

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