Week 8 - Docker and Deployment

📘 Overview

Welcome to Week 8 of the Learn Java for Beginners mentorship program.

In the previous weeks, you learned:

Core Java programming
Collections and exception handling
File IO and multithreading
Design patterns
Spring Boot development
JPA and Hibernate
Testing and validation

Now it is time to learn how real backend applications are packaged, deployed, and executed in modern environments using Docker.

This week introduces containerization concepts and deployment fundamentals that are essential for modern backend developers and cloud-native engineers.

🎯 Learning Objectives

By the end of this week, you should be able to:

Understand what Docker is and why it is used
Understand containerization fundamentals
Create Docker images for Java applications
Write and understand Dockerfiles
Build and run Docker containers
Use Docker Compose for multi-container applications
Containerize a Spring Boot application
Run a backend application with a database using Docker Compose
Understand basic deployment concepts

📚 Topics Covered

1. Introduction to Docker

What is Docker
Containers vs Virtual Machines
Why containers are important
Advantages of containerization

2. Docker Fundamentals

Docker Engine
Docker Images
Docker Containers
Docker Registry
Docker Hub

3. Essential Docker Commands

docker build
docker run
docker ps
docker images
docker logs
docker exec
docker stop
docker rm

4. Writing Dockerfiles

Dockerfile structure
Base images
COPY instruction
WORKDIR
EXPOSE
ENTRYPOINT
CMD

5. Containerizing Spring Boot Applications

Building executable JAR files
Creating Docker images for Spring Boot
Running Spring Boot containers

6. Docker Compose

Multi-container applications
Connecting application and database
docker-compose.yml basics

7. Basic Deployment Concepts

Local deployment
Environment variables
Port mapping
Persistent storage basics
Introduction to cloud-native deployment concepts

🛠 Practical Activities

During this week, you will:

Install Docker
Build your first Docker image
Run Java applications inside containers
Create Dockerfiles
Containerize your Spring Boot application
Run MySQL/PostgreSQL using Docker
Connect Spring Boot with database containers
Use Docker Compose to manage services

🧪 Testing Focus

As part of this week, you should verify:

Whether containers start correctly
Whether application logs are visible
Whether APIs are reachable
Whether database connections work properly
Whether port mappings are configured correctly

You should also practice debugging failed containers using logs and Docker commands.

📂 Files in This Week

File	Purpose
study-material.md	Detailed learning material
exercises.md	Practice exercises
assignment.md	Weekly implementation assignment
quiz.md	Conceptual and practical quiz
assessment.md	Weekly assessment criteria
review-checklist.md	Weekly mentor review checklist
solutions.md	Reference solutions and explanations

⏱ Recommended Schedule

Activity	Suggested Time
Study Material	3-4 Hours
Hands-on Practice	4-5 Hours
Exercises	2 Hours
Assignment	3-4 Hours
Review Preparation	1 Hour

🧠 Mentorship Guidance

This week is extremely important because it bridges the gap between:

Writing code and
Running applications in real environments

Modern backend engineers are expected not only to write APIs but also to understand how applications are packaged, deployed, and executed reliably.

Take your time to understand the workflow practically by running commands and debugging issues yourself.

✅ Expected Outcome

By the end of Week 8, you should be capable of:

Packaging backend applications using Docker
Running containerized Spring Boot applications
Managing application dependencies using Docker Compose
Understanding basic deployment workflows
Troubleshooting container-related issues

🚀 Next Steps After This Week

After completing this week, you can continue learning:

Kubernetes
OpenShift
CI/CD Pipelines
Helm Charts
Cloud Deployments
Container Security
Observability and Monitoring

📜 License

This project is licensed under the GNU GPL-3.0 License.

Maintained by Aditya Pratap Bhuyan LinkedIn: https://linkedin.com/in/adityabhuyan