🐳 Spring Boot with MySQL & Adminer using Docker Compose

This project demonstrates how to containerize a Spring Boot application with MySQL and Adminer using Docker Compose.

• Swagger Url: http://localhost:8080/swagger-ui/index.html#/
• UI Url: http://localhost:8080/

📌 Project Structure

project-root/
├── src/main/java       # Java source code
├── src/main/resources  # Configuration files
├── Dockerfile          # Defines how to build the Spring Boot app image
├── docker-compose.yml  # Defines multi-container setup
├── README.md           # Project documentation

🧑‍💻 Technologies Used

• Spring Boot
• Spring Web
• Thymeleaf
• HTML/CSS/JavaScript

🔧 Services Overview

• MySQL (mysql-service)
  • Runs MySQL database on port 3306 (internal Docker network)
  • Stores data in a persistent volume
• Spring Boot Application (springApplication-service)
  • Connects to MySQL at mysql-service:3306
  • Exposes API on port 8080
• Adminer (adminer-service)
  • Provides a web-based database UI
  • Runs on port 8081 (accessible from browser)

📡 Docker Network Diagram

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🚀 Getting Started

1️⃣ Clone the Repository

git clone https://github.com/beneite/SpringBootBasics.git
cd SpringWithDocker

2️⃣ Build and Run Containers

docker compose --profile entireApp up --build

• --profile entireApp will spin up the tagged services with 'entireApp' only
• -d runs containers in detached mode
• --build forces a rebuild of the Spring Boot image
• The docker compose will also take care of building the docker file/image.
• The docker file used is a multistage where in stage 1st i am creating the .jar file using the same in 2nd stage to bring the application up.

3️⃣ Check Running Containers

docker ps

4️⃣ Access Services

• Spring Boot API → http://localhost:8080
• Adminer UI → http://localhost:8081
  • System: MySQL
  • Server: mysql-service
  • Username: ashish
  • Password: ashish@123
  • database: userManagementDb

5️⃣ Stop and Remove Containers

docker-compose --profile entireApp down

🔹 Explanation of docker-compose.yml File

docker-compose.yml file defines four services and uses Docker Compose profiles to control which services start together.

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🚀 Services Breakdown

1️⃣ MySQL Service for entireApp Profile (mysql-service)

  mysql-service:
    image: mysql:latest
    environment:
      MYSQL_DATABASE: userManagementDb
      MYSQL_ROOT_PASSWORD: ashish@123
      MYSQL_USER: ashish
      MYSQL_PASSWORD: ashish@123
    volumes:
      - ./src/main/resources/dockerizedEntireApp/init-script:/docker-entrypoint-initdb.d
      - ./src/main/resources/dockerizedEntireApp/volumes/mysql_data:/var/lib/mysql
    profiles:
      - entireApp

🔹 Purpose:

• Runs a MySQL database only when using the entireApp profile.
• Stores database files in a persistent volume (mysql_data).
• Initializes the database using scripts from init-script.

🔹 Why No ports Mapping?

• The MySQL container is not accessible from outside Docker because there is no port mapping (8082:3306).
• It can be accessed only by other services inside Docker (like springApplication-service).

---

2️⃣ MySQL Service for onlyDb Profile (mysql-service-onlyDb)

  mysql-service-onlyDb:
    image: mysql:latest
    environment:
      MYSQL_DATABASE: userManagementDb
      MYSQL_ROOT_PASSWORD: ashish@123
      MYSQL_USER: ashish
      MYSQL_PASSWORD: ashish@123
    ports:
      - "8082:3306"
    volumes:
      - ./src/main/resources/dockerizedEntireApp/init-script:/docker-entrypoint-initdb.d
      - ./src/main/resources/dockerizedEntireApp/volumes/mysql_data:/var/lib/mysql
    profiles:
      - onlyDb

🔹 Purpose:

• Runs a separate MySQL instance when using the onlyDb profile.
• Exposes port 8082:3306 so you can connect to the database from outside Docker (e.g., via MySQL Workbench, a local application, etc.).

🔹 Why a Separate Service?

• Docker Compose profiles do not support conditional port mappings.
• This duplication allows one version of MySQL to expose a port (8082:3306) while the other does not.

---

3️⃣ Adminer Service (adminer-service)

  adminer-service:
    image: adminer
    ports:
      - "8081:8080"
    profiles:
      - onlyDb
      - entireApp

🔹 Purpose:

• Runs Adminer, a web-based database management tool (like phpMyAdmin).
• Accessible at http://localhost:8081 in your browser.
• Included in both profiles (onlyDb and entireApp) so that it works in both modes.

---

4️⃣ Spring Boot Application (springApplication-service)

  springApplication-service:
    build: .
    image: userserviceimage:v1
    ports:
      - "8080:8080"
    environment:
      spring.datasource.url: "jdbc:mysql://mysql-service:3306/userManagementDb?useSSL=false&allowPublicKeyRetrieval=true"
    depends_on:
      - mysql-service
    profiles:
      - entireApp

🔹 Purpose:

• Runs a Spring Boot application.
• Accessible at http://localhost:8080.
• Connects to MySQL (mysql-service) using JDBC.

🔹 Key Configuration:

• Depends on mysql-service, meaning MySQL starts before Spring Boot.
• Database URL:

  jdbc:mysql://mysql-service:3306/userManagementDb
  

  This tells Spring Boot to connect to the MySQL service inside Docker.

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🎯 How Profiles Work in This Setup

1️⃣ Running Only the Database (onlyDb Profile)

docker compose --profile onlyDb up

✔ Starts:
✅ mysql-service-onlyDb (with 8082:3306 exposed).
✅ adminer-service.
❌ Does NOT start Spring Boot (springApplication-service).

2️⃣ Running the Full Application (entireApp Profile)

docker compose --profile entireApp up

✔ Starts:
✅ mysql-service (without exposing ports).
✅ adminer-service.
✅ springApplication-service.
❌ Does NOT start mysql-service-onlyDb (no duplicate MySQL).

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🔥 Why This Approach is Useful

✔ Avoids exposing MySQL publicly when not needed.
✔ Allows local access (8082:3306) when using onlyDb profile.
✔ Keeps entireApp profile isolated (Spring Boot can access MySQL internally).